key: cord-0063015-742ki3eh
authors: nan
title: Abstracts for the 2021 TSANZ Annual Scientific Meeting
date: 2021-05-06
journal: Transplant Direct
DOI: 10.1097/txd.0000000000001167
sha: d62e9e3b9cb8f0b3b1b27dca088beeed065fc2ca
doc_id: 63015
cord_uid: 742ki3eh

nan

Aims: Molecular alterations in hearts donated after circulatory death (DCD) are poorly understood. We aimed to characterise the phosphorylation status of key elements of signaling pathways with mitochondria as downstream target in hearts from a rat DCD model. Methods: Male Wistar rats were anesthetized, carotid artery cannulated for blood pressure monitoring, 500IU heparin injected, and trachea ligated. Circulatory arrest was declared when pulse pressure zeroed. Animals were randomised into either 10-, 15-or 20-minute asystolic warm ischemic times (aWIT) before hearts were excised and reperfused ex vivo 37oC, 1hr) . Sham group hearts were removed after heparin injection without tracheal ligation. Cardiac functional recovery was assessed by measurement of cardiac output, heart rate and coronary flow during reperfusion. LV tissues were collected at the end of reperfusion for western blots of total and phosphorylated AMPK, Erk, Akt, Stat3 and Drp1. Results: Compared to sham, cardiac functional recovery after reperfusion of all DCD hearts were significantly decreased proportional to aWIT (Table 1) . AMPK phosphorylation was significantly decreased in DCD hearts at the end of reperfusion (Fig 1a) , while Drp1 and Stat3 phosphorylation were increased (Fig 1b,1c) . Differences between DCD hearts were not significant. Phosphorylated Erk and Akt were increased significantly only in DCD20 hearts (Fig 1d,1e) . Background: Tolerogenic dendritic cells (TolDC) have the ability to regulate the innate immune response and we hypothesize they can provide protection in acute kidney injury (AKI). Aims: To determine if adoptively transferred TolDCs can reduce inflammation and severity of AKI. Methods: Bone marrow-derived TolDC were cultured from C57BL/6 (SynTolDC) or BALB/c mice (AlloTolDC) in media containing vitamin-D and interleukin-10 ± LPS on day 6. TolDC were harvested at day 7, enriched by CD11c + sorting and 1x10 6 cells were infused into 12-week-old male C57BL/6 mice the day prior to bilateral renal ischemia reperfusion injury (IRI). Mice were analyzed 24hours post-reperfusion for renal function, histology and biomolecular phenotyping. Results: Both AlloTolDC and alternatively activated LPS-SynTolDC protected against IRI compared to PBS-treated controls (creatinine 43.5±38.4, 18.2±8 vs 122±49.7μmol/L respectively, p<0.001).

There was less histological injury in AlloTolDC and LPS-SynTolDC groups compared to control, with diminished cell death (2.3±1.5, 4.87±3.2 vs 25.9±6.7 TUNEL+ve cells/hpf respectively, p=0.02). mRNA analysis of kidney homogenate demonstrated significant reduction in pro-inflammatory cytokine expression (IL-6, IL-1β, TNFα, CCL2, CXCL2) but no changes in antioxidant profile (SOD, iNOS, NADPH oxidase). CellViolet-labelled TolDC allowed detection in the kidney 24hrs post-IRI and tended to be higher in the LPS-STolDC group compared to STolDC alone (13.6% vs 6.7% of CD45+ cells, p=0.18). Whole kidney flow cytometry of immune cell populations demonstrated pro-inflammatory macrophages (CD11b+F480+Ly6C-hi) were lower in the LPS-SynTolDC group compared to controls (15.9 vs 33.5%, p=0.05). Conclusion: TolDCs demonstrate potent protective effects against renal IRI, with reduced levels of inflammation and cell death. Short and long-term kidney allograft outcomes are significantly influenced by the second warm ischaemic time (SWIT), which occurs during vascular anastomoses. This leads to time pressure and potentially technical complications, resulting in allograft loss. Intraoperative thermal regulation of the kidney could reduce the second warm ischaemic injury, minimising surgical complications due to easing time pressure, and reducing the ischemia-reperfusion injury (IRI).

Methods: A novel ischaemic-injury thermal protection jacket (iiPJ™) was developed in silicone and polyurethane (PU) variants, with no thermal insulation as the control. An ex vivo water bath model was developed to determine the thermal properties of porcine kidneys and study the insulative effect of the iiPJ™. The time taken to reach 15°C (metabolic threshold) was measured, with thermal energy transfer calculated from the area under the curve. Results: For both iiPJ™ versions, the time taken to reach the 15°C threshold was 35.2±1.4 minutes (Silicone), 38.4±3.1 minutes (PU), with 17.2±1.5 minutes for controls (n=5, P<0.001). The thermal energy transfer was also significant for both iterations of the iiPJ™ when compared to controls. The material selection of the iiPJ™ showed no significance. Conclusion: Insulating jackets are a potential method of protection from the second warm ischemic injury. With ongoing experiments including feasibility studies using discarded human kidneys, and a pilot clinical trial, clinical translation of the iiPJ™ through collaborative multi-centre clinical trials could improve surgical performance, facilitate teaching and training, decrease the second warm ischaemic injury and incidence of IRI, with improved short-and long-term outcomes. Background. Ischemia-reperfusion injury (IRI) detrimentally affects the function of transplanted organs. Ischemia increases acidity in affected tissue, activating the cell surface acid sensor ASIC1a and triggering cell death. The prototypic ASIC1a inhibitor psalmotoxin 1 (PcTx1), isolated from a South American tarantula, protects in murine models of stroke and renal IRI. Hi1a is a highly stable ASIC1a inhibitor from the Australian funnel web spider with superior specificity, potency and pharmacokinetic properties. We investigated whether targeting ASIC1a with Hi1a would protect against injury in a mouse model of unilateral renal IRI.

Methods. C57BL/6 mice underwent right nephrectomy followed by 22 min left renal ischemia, and were euthanased 24 hr after reperfusion for analysis of renal function (serum creatinine). Treatment groups (n=8) were injected intravenously with Hi1a 30 min pre-ischemia (100 µg/kg) or immediately post-reperfusion (100 µg/kg or 1000 µg/kg). PcTx1 was used as a comparator in the post-reperfusion treatment study.

Results. IRI is induced in this model as indicated by increased serum creatinine levels in vehicle control mice compared with sham (pandlt;0.0001). Pre-ischemia administration of 100 µg/ kg Hi1a was not protective. However, post-ischemia treatment dose-dependently preserved renal function. PcTx1 given post-reperfusion in an equimolar amount to the higher dose of Hi1a was similarly protective. Conclusion. Therapeutic administration of Hi1a significantly protected against renal IRI. These results confirm that ASIC1a is involved in the pathophysiology of renal IRI and identify Hi1a blockade as a promising new approach to improve organ transplant function.

Sligar C 1 , Adhikary S 2 , Sluyter R 1 , Watson D 1 1 Illawarra Health and Medical Research Institute, University of Wollongong, 2 University of Queensland

Background : Hematopoietic stem cell transplantation (HSCT) is a curative therapy for steroid refractory blood cancers. However, donor HSCT is restricted by the occurrence of graftversus-host disease (GVHD) in up to 60% of transplant recipients. Single nucleotide polymorphisms (SNPs) in the promoter region of the interleukin-6 gene (IL6) have been associated with numerous inflammatory diseases, including GVHD. The rs1800795 (-174 G → C) SNP in the promoter region of IL6 affects expression levels of interleukin (IL)-6 and may influence GVHD in HSCT recipients. Aim: To determine the effect of donor rs1800795 IL-6 SNP genotype of the development of GVHD in a humanised mouse model. Methods: A retrospective analysis was performed on data from NOD-SCID-IL2Rγnull (NSG) mice injected with hPBMCs isolated from donors either homozygous or heterozygous for the G allele (IL-6GG/GC mice) or donors homozygous for the C allele (IL-6CC mice) of the rs1800795 SNP.

Results: A lower splenic CD4+:CD8+ T cell ratio was observed in IL-6GG/GC mice compared to IL-6CC mice at three weeks post-transplant. However, both IL-6GG/GC and IL-6CC mice demonstrated similar proportions of CD4+ and CD8+ T cells at endpoint. IL-6GG/CC and IL-6CC mice developed GVHD, with comparable clinical scores. However, there was a significant decrease in median survival time (MST) in IL-6GG/CC mice (MST = 36 days, n = 62) compared to IL-6CC mice (MST = 46 days, n = 15) (P = 0.0242). Donor rs1800795 SNP genotype, however, did not influence GVHD-mediated tissue damage in the liver, skin, ear or duodenum of NSG mice. Conclusion: Donor rs1800795 SNP genotype can influence survival and T cell ratios at early time-points in humanised NSG mice, supporting a role for IL-6 in GVHD development in humanised mice and humans.

Introduction: Lung allografts contain large populations of donor-derived lymphocytes. The effect these lymphocytes have on lung allograft outcome it is not yet fully understood. We aimed to assess the proportion and phenotype of these "passenger" lymphocytes and establish a possible link with the development of chronic lung allograft dysfunction (CLAD). Methods: Flow cytometric analyses was performed on blood and bronchoalveolar lavage (BAL) from 17 lung transplant recipients from 2 weeks to 18 months post-transplant utilizing antibodies to (a) delineate lymphocyte subsets and donor and recipient HLA and (b) to identify lymphocyte subsets. These findings were then correlated to the development of CLAD within 3 years post lung transplant.

Results: Donor-derived lymphocytes were observed in the blood of lung transplant recipients and constituted 0-2% lymphocytes. This frequency declined rapidly in 10 patients reaching undetectable levels of donor-derived lymphocytes at 6 months post-transplant. However, in 3 patients, low levels of chimerism (andgt;0.5%) persisted and were observed 18 months post-transplant. The frequency of donor-derived lymphocytes in BAL decreased less rapidly following transplantation, with higher levels at 2 weeks (5-90%) and 18 months (0-20%) post-transplant than blood. Interestingly, patients with confirmed CLAD at 3 years post-transplant had on average lower initial lymphocyte chimerism (Blood: 0.64% vs 0.99%, BAL: 22.6% vs 55.2%) and reached undetectable levels earlier than patients without CLAD. Conclusion: These results support the hypothesis that donor-derived lymphocyte populations may play an important role in the modulation of the immune environment of lung allografts following transplantation. Grant support: Lungitude Foundation Figure 1 . Mean-Dispersion plot illustrating the range of differentially expressed gene within a dataset. Significant genes are coloured according to their log fold change and significance level. Genes upregulated and downregulated when comparing tolerogenic dendritic cell groups are coloured red and blue respectively.

Perkins G 1 , Kim J 1 , Hope C 2 , Coates T 3 , Hurtado P 4 1 School of Biological Sciences, University of Adelaide, 2 Paediatric Medicine, Women's and Children's Hospital, 3 Central and Northern Area Renal Transplantation Service, Royal Adelaide Hospital, 4 School of Medicine, University of Adelaide

Background: Th1 vs Th2 cytokines in allograft rejection is well established. More recently, B-cells cytokines have also been found to play an important role. Immature B-cells in particular have been implicated in transplant tolerance, and their polarisation towards IL-10 producing regulatory cells is predictive of favourable longterm kidney transplant outcome. Cytokine secretion is driven by toll-like receptor (TLR) ligands, which are released during transplantation, and initiate and direct the immune response. Aim: To identify mechanisms regulating the cytokine profile of TLR-stimulated B-cells, and to measure the influence exerted on the human immune response.

Methods: Untouched human B-cells (purity >97%) were cultured with CpGB DNA to stimulate IL-10 production, and Th1 and Th2 cytokines were investigated as regulators of the B-cell IL-10 response by ELISpot, ELISA, cytokine bead-array, intracellular flow cytometry, and using a B-cell-derived NF-kB reporter cell line. Regulatory capacity was assessed with a novel plasmacytoid dendritic cell (pDC) suppression assay.

Results: In response to TLR9 stimulation, secretion of cytoplasmic IL-10 was decreased in IL-4 primed B-cells by 60-80% (p=0.01). Conversely, IL-6 secretion was increased (p=0.017). IL-4 selectively modulated cytokine secretion without affecting canonical TLR signalling, or activation. In preliminary experiments, IL-4 primed B-cells were impaired in their capacity to suppress pDC function (p=0.2). Interferon-α/β/γ all restored IL-10 secretion in a dose-dependent manner. Conclusion: Th1 and Th2 microenvironments counter-regulate the suppressive function of TLR-activated B-cells. This work adds to our understanding of the immune networks governing tolerance vs inflammation and will inform ongoing research into B-cell targeted therapies for transplantation.

Introduction: The pig has become an important and increasingly used large animal model in transplantation, and in particular in islet transplantation. However, the effects of immunosuppressive drugs on pig cells have not been extensively studied. Aim: To assess the effect of calcineurin inhibitor tacrolimus on pig-T cell proliferation in vitro.

Methods: CellTrace™ Violet labelled pig-T cells were cultured with 1-10 µg/ml phytohemagglutinin (PHA) with or without tacrolimus (5, 20, 100 ng/ml) for 3-6 days, and in 5 day Mixed lymphocyte reaction (MLR) with human PBMC as stimulators. Suppression of proliferation was assessed by flow cytometry. The effect of tacrolimus on interleukin-2 (IL-2) messenger RNA was assessed in Real-time PCR.

Results: Pig T-cells stimulated with 10 µg/ml PHA reached over 90% proliferation after 5 days in culture, comparable to human T-cells. While 20 ng/ml tacrolimus inhibited proliferation of human T-cells at 5 days by 50-70%, pig T-cell proliferation was not inhibited. However, in PHA dose (1 -10 µg/ml) and time response experiments, significant inhibition of pig T-cell proliferation was observed at days 3 and 4, and not days 5 and 6. In 5 day MLR, pig T-cell proliferation was inhibited by tacrolimus, comparable to inhibition in human MLR. Pig IL-2 messenger RNA was upregulated with PHA and in MLR, and downregulated with tacrolimus at 24 h, 3 and 4 days and was reduced to background levels by days 5 and 6. Conclusion: In our in-vitro studies, mitogen and MLR stimulated pig-T cells proliferated efficiently and were inhibited by tacrolimus.

T Cell Biology PD-L1/PD-1 INTERACTIONS ARE CRITICAL FOR  TOLERANCE INDUCTION IN PRIMED SKIN GRAFT  RECIPIENTS FOLLOWING LIVER-DIRECTED MHC CLASS I  GENE TRANSFER Leong M School of Medicine, University of Sydney

Background : Transduction of C57BL/6 hepatocytes with donor MHC class I results in tolerance to subsequent skin grafts expressing the same mismatched allomorph. C57BL/6 (H-2 b ) CD8 + T cells encountering H-2K d in the liver express high levels of PD-1 1 . We aimed to determine whether PD-L1/PD-1 axis contributes to resolution of inflammation and investigate the contribution other coinhibitory molecules TIM3 and TIGIT may have towards tolerance induction. Methods: Naïve or primed C57BL/6 or PD-L1 KO mice (both H-2 b ) were inoculated with AAV-K d 5x10 11 vgc and samples collected for biochemistry, immunostaining and flow cytometry. Mice were challenged with B6.Kd skin grafts d7 post inoculation with AAV-K d alone, or in combination with twice weekly administration of anti-TIM3, anti-TIGIT or isotype control antibodies post AAV-K d administration.

Results: Liver ALT levels and morphology remained normal in AAV-K d -treated naïve C57BL/6 and PD-L1 KO mice. K d expression was near maximal by d7 persisting though d28 post inoculation. In primed C57BL/6 mice ALT peaked on d7 (269 ± 18.8 IU/L) before returning to baseline levels by d28. K d expression reflected that in naïve mice. Severe widespread inflammation was seen in primed PD-L1 deficient mice. ALT levels peaked on d7 (1364 ± 273.6 IU/L), with marked elevation of CD4 + and CD8 + T cells. K d expression was rapidly lost by d28 post inoculation. Untreated C57BL/6 and PD-L1 KO mice all rejected B6.Kd skin grafts. Tolerance to B6.Kd skin grafts was achieved in all AAV-K d treated naïve C57BL/6 and PD-L1 KO mice, and in C57BL/6 mice primed by rejection of a K d -bearing skin graft. In PD-L1 KO mice, concurrent blockade of TIM3 after AAV-K d resulted in abrogation of tolerance (MST 17 days) and concurrent TIGIT blockade resulted in 1 of 6 grafts surviving indefinitely. In primed C57BL/6 mice, blockade of TIM3 after AAV-K d resulted in 1 of 3 recipients achieving indefinite survival, and TIGIT blockade resulted in abrogation of tolerance (MST 43 days). Primed PD-L1 KO mice receiving AAV-K d rejected B6.Kd skin grafts with rapid tempo (MST 9.5 days).

Conclusions: The PD-L1/PD-1 axis is dispensable for control of inflammation and tolerance induction after AAV-K d inoculation in naïve mice, presumably because of the redundancy of co-inhibitory pathways. Blockade of these co-inhibitory pathways resulted disrupted tolerance induction and resulted in incomplete tolerance induction or complete abrogation of tolerance. Aims: We have recently identified over 40 H-2K b -peptide epitopes that are directly recognised by CD8 + T cells from allogeneic B10. BR (H-2 k ) or BALB/c (H-2 d ) mice. Some "super-epitopes" are strongly recognised by T cells from both strains. Here, we aimed to characterise the T cell receptor (TCR) repertoire responding to these epitopes. Methods: B10.BR or BALB/c mice were primed with a K b -bearing skin graft, and boosted by inoculation with AAV-K b . Single-cell index sorting was followed by multiplex nested PCR and sequencing of PCR products. The TCR sequences from dextramer-positive and PD-1bystander populations were compared. Results for K b -SNYLFTKL are described.

Results: 5-7 dominant clonotypes each representing between 4.2 and 26.7% of TCRs were found in the dextramer-positive cells from both B10.BR and BALB/c mice, while no clonal expansion was detected in the PD-1cells from either strain. Among the dominant clonotypes, 85.8% of B10.BR clones and 60.1% of BALB/c clones used the TRBV13-2 segment, and strong pairing preferences were observed, with B10.BR cells using mainly TRAV14-1 or TRAV16D/DV11 in combination with TRBV13-2, while BALB/c cells principally used TRAV12D-2 or TRAV16D/DV11 in conjunction with TRBV13-2. Despite the pairing of TRAV16D/DV11 -TRBV13-2 being utilised by both B10.BR and BALB/c, only one CDR3b sequence was common to clones from the two strains.

Conclusions: A limited number of dominant clonotypes are present within the T cell populations recognising K b -SNYLFTKL. Biophysical and structural studies of these and additional receptor-ligand pairs will enhance our understanding of the basis for alloreactivity. Figure 1 . Dominant clonotypes were discovered within the activated (CD44 + PD1 hi ) K b-SNYLFTKL Dex + CD8 + T cell populations from both B10.BR and BALB/c mice, indicated in shading. Clone with common CDR3b region shown in black shading. By comparison, no clonal expansion was present in the PD1cells. Conclusions: These data demonstrate key differences in immune response to variations in tissue and MHC mismatch in transplantation in the absence of immunosuppression. These findings may help us to better target immunosuppression post-transplantation in organ recipients.

Background : Blockade of the B7-CD28 and CD40-CD154 pathways induces tolerance towards porcine-islet-cell-cluster (NICC) xenografts in mice. Aims: 1) Investigate CD4 + Foxp3 + Tregs in mouse-model of NICC xenograft-tolerance, 2) identify in situ immune-cell subtypes using imaging mass cytometry (IMC) and 3) assess the function of these Foxp3 + Tregs. Methods: C57BL/6-DEREG-mice with diphtheria-toxin (DT)receptor/GFP attached to Foxp3-gene were transplanted with NICC under renal-capsule. Recipient-mice received CTLA-4-Fc and MR-1 mAb. Foxp3 + Tregs were depleted by DT from day 3-17 (induction-phase), or 80-100 days post-transplantation (maintenance-phase). NICC-xenograft function determined by insulin/ glucagon staining and serum porcine-c-peptide concentration. A 16-antibody panel for IMC was used to identify in situ cells and a bioinformatics pipeline was created for data analysis.

Results: More CD4 + Foxp3 + Tregs were seen in NICC-xenografts of treated mice on day-8 and 100 than day-20. Foxp3+ cells increased significantly in the draining-lymph-nodes of treated mice on day-8 (P=0.0010) and 100 (P=0.0128) when compared to the untreated/rejecting groups. CD4 + Foxp3 + Treg depletion led to rapid xenograft rejection. CD4 + Foxp3 + Tregs from lymphoid-organs of graft-tolerant DEREG-mice showed a significant increase in CD127, downregulated CD25, and reduced CD27 and CD62L expression compared to naïve/rejecting xenografts. IMC successfully quantified in situ immune-cell subsets (Fig. 1 ). CD127 +hi CD25 +/low CD44 +hi CD62L -CD27 -CD4 + Foxp3 + Tregs were transferred to NICC-transplanted Rag-\-mice and had a greater suppressive capacity than naïve-Tregs. Conclusion: Foxp3+Tregs are essential for NICC-xenograft survival in this model. Importantly, CD127 +hi CD44 +hi CD62L -CD27 -CD25 +/low CD4 + Foxp3 + Tregs were a subpopulation of Tregs that showed features of antigen-specific memory. IMC successfully visualised and quantified immune cell subgroups within the graft area, using supervised machine-learning and high-dimensional data analysis in R programming language.

Rakesh P, Verma N, Bedi S, Tran G, Hodgkinson S, Hall B Immune Tolerance Group, University of New South Wales

Aims: Naïve CD4 + CD25 + T regulatory cells (Treg) activated by antigen and rIL-4 generate Ts2 cells expressing IL-5Rα. Ts2 cells activated with rIL-5 and specific antigen generate more potent Th2-like Treg. Accurate assessment of specific in vitro suppression of effector cells is difficult due to presence of stimulator cells and Treg. We assessed the suppression by Th2-like Treg using a refined flow cytometry based assay. Methods: Th2-like Treg were generated by 4d culture of CD4 + CD25 + tTreg from naïve DA rats with PVG-stimulators and rIL-4 to generate Ts2 cells, which were further cultured with PVG-stimulators and rIL-5 for 3d. Serially diluted freshly isolated CD4 + CD25 + tTreg or Th2-like Treg were co-cultured for 5-7 days with constant number of CD4 + CD25 -T DA effector cells and PVG thymic stimulator cells. Suppression of CD4 + CD25 -T cell proliferation was analysed using FACS, and flow cytometry to assess the number of undivided CTV + CD4 + CD25 -T effector cells after exclusion of CFSE + stimulator cells and CD25-PE + Treg.

Results: CD4 + CD25 -T cells typically proliferated 5-6 cycles by 5d, consistent with 1-2% of original responder population proliferating against alloantigen. tTreg suppressed T effector cell proliferation at ratios of 1:1 to 1:4 (Treg:Responder). With Th2-like Treg, CD4 + CD25 -T cell proliferation was suppressed up to 1:128 or 1:512 in both 5 and 7 day cultures.

Conclusion: This assay specifically assessed the suppression of effector cells, avoiding interference from stimulator cells or Treg and confirmed that the two-step activation of tTreg, first with IL4/ antigen then IL-5/antigen, could induce highly potent Treg that suppress at high in vitro ratios of 1:128.

Scaffidi J 1 , Kim J 1 , Sadlon T 2 , bandara V 2 , Barry S 2 , Coates T 3 1 School of Medicine, University of Adelaide, 2 School of Women's and Children's Health, University of Adelaide, 3 Renal and Transplantation Unit, University of Adelaide Regulatory T cells (Tregs) have been extensively investigated as an alternative method of immunosuppression in transplantation. Antigen-specific Tregs are more superior to polyclonal Tregs in their migration to and persistence in target tissue, and prevention of unwanted widespread suppression. However, they are rare in peripheral blood, requiring significant expansion for therapeutic quantities, which can be costly and time-consuming. Therefore, this project aims to utilise chimeric antigen receptors (CARs) to confer antigen-specificity to Tregs. Method: We have generated lentivirus expressing various CARs specific for the Glutamic Acid Decarboxylase (GAD65), a key auto-antigen expressed in islets. These CARs differ in their spacer domain length (small, medium and large), a region between the antigen binding and transmembrane domain which is important for optimal CAR binding. CD3+ T cells isolated from human peripheral blood were transduced with this lentivirus and screened for CAR expression and antigen-specific proliferation.

We have generated GAD65-specific CAR T cells, with a high (70-90%) transduction efficiency. In addition, GAD65 CAR T cells with small and large spacer domains were highly viable with 88% and 73% proliferation respectively upon exposure to native GAD65 protein over a 5-day period, which was comparable with bead stimulation. Conversely, medium length spacer domain conferred andlt;20% proliferation and significantly lower viability. Moreover, when exposed to BSA, no proliferation was observed. The subcutaneous site represents an accessible alternative islet transplant site but suffers from poor vascularisation. Here we test a clinically proven Biodegradable-Temporising-Matrix; NovoSorb™ (IDT) repurposed from use in burn and wound treatment that may provide a platform for subcutaneous islet-transplants. IDT showed no impact on human islet viability in-vitro (Glucose-Stimulated-Insulin-Secretion). Mouse islets transplanted under the renal capsule of diabetic recipients pre-implanted with IDT resulted in complete recovery and long-term maintenance of euglycemia (>100-days). Neonatal porcine islets (NPI) transplanted with IDT showed increasing porcine insulin production through time (>300-days). Therefore IDT does not interfere with physiological function of human islets, mouse islets and NPI's. Mice were then transplanted with IDT alone to model the in-vivo foreign body reaction and assess formation of blood vessels and the tissue remodelling process (Zeiss 7MP two-photon microscope). We used transgenic (LysM-GFP+/tdTomTg) mice: blood vessels express tdTomato red and Lysozyme+ myeloid cells express GFP. At day 7 infiltrating LysM-GFP positive cells were clearly seen within the graft site with some cells showing proximity to the IDT. At day 14, LysM-GFP cell fusion events had occurred with the formation of giant cells, which appeared to be enriched along the exposed surface of the IDT. At day 30 the infiltrating cells changed to cells with dendritic appearance. Changes in cell populations accompanied tissue remodelling at the graft site. Vascular networks expressing tTomato red were further revealed by systemic infusion of Evans Blue. This allowed the visualisation of fine but scattered immature vascular networks at day 7 with dispersed loose collagen fibrils. By day 30 the vessels were characterised by increased branching and density whereas collagen increased in fibre thickness and density. This was particularly evident on the 'dorsal' face of the IDT in direct contact with the kidney parenchyma. To assess whether innate sensing of the islet graft would occur in the absence of a supportive scaffold, we transplanted islets from whole body tdTomTg mice (Tomato positive islets) into (LysM-GFP/+) mice and grafts were imaged 24 hour post transplantation. LysM-GFP positive cells were readily imaged migrating over the surface of Tomato-positive islets, and in some fields LysM-GFP positive cells were observed exhibiting neutrophil like 'swarming' behaviour with evident remodelling of Tomato-positive islet tissue. This analysis reveals a dynamic interaction between the innate immune system and both the newly engrafted islet and supportive matrix. This analysis reveals a dynamic interaction between the innate-immune system and the islet graft +/-IDT and that IDT can provide a neo-vascularization platform advantageous for subcutaneous islet transplantation. 

Bird K 1 , Adhikary S 1 , Casolin S 1 , Cuthbertson P 1 , Sluyter R 1 , Alexander S 2 , Watson D 1 1 Illawarra Health and Medical Research Institute, University of Wollongong, 2 The Children's Hospital at Westmead, Sydney

Background : Post-transplant cyclophosphamide (PTCy) decreases graft-versus-host disease (GVHD) incidence in humanised NOD-SCID-IL2Rγ null mice, as demonstrated by lowered clinical scores and prolonged survival. However, the mechanism of PTCy-mediated protection remains unclear. Furthermore, the involvement of the skin in GVHD remains largely unexplored in humanised mice. Aim: To investigate the mechanism of PTCy-mediated protection against GVHD and to further characterise GVHD involvement in the skin in humanised mice.

Methods: NOD-SCID-IL2Rγ null mice were injected i.p. with 20 x 10 6 human peripheral blood mononuclear cells (day 0) followed by PTCy (33 mg/kg) or saline (day 3 and 4). Mice were monitored for GVHD for up to 10 weeks. Human cell engraftment was examined by flow cytometry and gene expression measured by qPCR. Results: At week 3, PTCy-mice with subclinical GVHD (clinical score < 5) displayed significantly decreased proportions of blasting (proliferating) hCD3 + T cells in the blood. PTCy-mice with subclinical GVHD showed prolonged survival (MST >70 days) compared to PTCy-mice with clinical GVHD (clinical score > 5) and saline control mice. PTCy-mice with subclinical GVHD displayed reduced Tregs and increased hCD4 + :hCD8 + T cell ratios compared to PTCy-mice with clinical GVHD. PTCy did not impact TBX21, RORC, GATA3 or FOXP3 gene expression in the spleen, liver, small intestine or skin, or IFNG, IL17 and mREG3G gene expression in the skin. Conclusion: These findings indicate that the impact of PTCy on effector donor T cells may be of greater importance than donor Tregs or Th cell subsets in delaying GVHD development in this humanised mouse model.

Penko D 1 , Nitschke J 1 , Johnston J 1 , Kireta S 1 , Drogemuller C 1 , Greenwood J 2 , Coates P 1 1 Central Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital, 2 Adult Burn Centre, Royal Adelaide Hospital Introduction: One of the major limitations currently for islet transplantation is loss of pancreatic islets due to the instant blood mediated inflammatory response (IBMIR). IBMIR is triggered when the islets are delivered into the portal circulation during transplantation into the liver. Furthermore, islets that survive IBMIR still need to embed themselves into the liver vasculature and reestablish their own intra-islet blood supply to survive and function longterm. Previous work within our lab has demonstrated the ability of a Biodegradeable Temporizing Matrix (BTM) scaffold to create a hypervascularised intracutaneous site suitable for islet transplantation in a porcine transplant model, thus avoiding the IBMIR. Aim: To investigate alternate delivery method of islets into the hypervascularised intracutaneous space. Method: Elliptical wound of 80mmx40mm created in Large White x Landrace on side flank near hind leg by removing skin and subcutaneous tissue for BTM implantation ( Figure 1 ). Following engraftment of BTM (15-35days), islets are delivered into crease of BTM formed by folding the site prior to suture closure. Islet survival and vasculature was assessed by histological analysis following graft removal at 7, 14 and 28 days following transplantation.

Results: Chromogranin A positive islets present in intracutaneous BTM space 7, 14 and 28 days following transplantation. Intracutaneous space was well vascularised, with islet graft in close proximity to vasculature which was evident from day 7 following transplantation.

Conclusion: The current site poses great potential as a viable site for islet transplantation that can be applied in a clinical setting.

Kong J 1 , Ellis C 1 , Gilfillan C 2 , Lee D 1 

Zammit N 1 , Seeberger K 2 , Zamerli J 1 , Walters S 1 , Lisowski L 3 , Korbutt G 2 , Grey S 1 1 Immunology, Garvan Institute of Medical Research, Sydney, 2 Department of Surgery, University of Alberta, 3 Immunology, University of Sydney Neonatal porcine islets (NPIs) can restore glucose control in mice, pigs, and non-human primates, representing a potential abundant alternative islet supply for clinical beta cell replacement therapy. However, NPIs are vulnerable to inflammatory insults that could be overcome with genetic modifications. Here we demonstrate in a series of proof-of-concept experiments the potential of the cytoplasmic ubiquitin-editing protein A20, encoded by the TNFAIP3 gene, as a NPI cytoprotective gene. Forced expression of A20 in NPI grafts using a recombinant adenovirus 5 (Ad5) vector suppressed TNF-stimulated NF-κB activation by inhibiting IκBα phosphorylation and degradation and reduced the induction of pro-inflammatory genes Cxcl10 and Icam1. Forcing the expression of A20 had no negative impact on glucose stimulated insulin secretion. A20-expressing NPIs exhibited superior functional capacity when transplanted into diabetic immunodeficient recipient mice, evidenced by a more rapid return to euglycemia and improved GTT compared to unmodified NPI grafts. Adeno-associated vectors (AAV) are clinically preferred vectors but exhibit poor transduction efficacy in NPIs. To overcome this obstacle, we screened a series of AAV serotypes, and optimised NPI culture conditions selecting for a combination with maximal NPI transduction efficiency. We report an AAV2 based procedure that achieves >70% transduction rates in NPIs without adverse impact upon NPI maturation and is able to deliver therapeutic A20 to suppress NPI inflammatory responses. This new protocol allows for high-efficiency genetic modification of NPIs, which can be utilised to introduce candidate genes without the need for germline engineering. This approach would be suitable for preclinical and clinical testing of cytoprotective molecules like A20. In multivariate analysis, DQ REM status was significantly associated with an increased risk of CLAD after adjustment for native lung disease (HR 1.85, 95% CI 1.10-3.12, p=0.02). There was a significant difference in the cumulative incidence of CLAD based on DQ REM status p= 0.03 [ Figure 1 ]. Conclusion: DQ REM status was significantly associated CLAD free survival. Avoidance of DQ REM at the time of transplant, represents a possible strategy to reduce early onset CLAD. However, transplantation across DQ REM may be an acceptable strategy for urgent recipients. Figure 1 . Cumulative incidence of CLAD in bilateral lung transplant recipients based on DQ REM status. Curves compared using the Log Rank test. Aims: We aimed to determine the perinatal outcomes in transplanted mothers compared to births in dialysed mothers, births occurring before a mother started any kidney replacement therapy (before-KRT), and mothers who never received KRT (non-KRT (Table 1) .

Transplanted mothers were older compared to others and had higher rates of pre-existing diabetes and hypertension than the non-KRT cohort. A higher proportion of transplanted mothers underwent caesarean sections than non-KRT cohort, similar to dialysis and before-KRT cohorts. Transplanted mothers had similar proportion of livebirths compared to before-KRT cohort, higher than in dialysed mothers and lower than the non-KRT cohort, and a large proportion of babies were admitted to neonatal intensive care unit or special care nursery. Babies born to mothers receiving KRT had lower gestational age and birthweight. These babies had lower APGAR scores, needed resuscitation, and stayed longer in the hospital.

Conclusions: The incidence of maternal comorbidities, adverse pregnancy and birth outcomes remain as major concerns for transplanted women. The novelty of the findings was the fact that birth outcomes in transplanted mothers were similar to that of before-KRT cohort. These findings will underpin the evidence-base for parenthood planning, decision-making and care for women who are considering or faced with parenthood, with kidney transplantation. Background : Multiple factors influence allograft outcomes such as kidney quality (KDPI), first warm ischaemia time (WIT) in DCD donors and anastomosis time (SWIT) in the recipient. We looked at 246 consecutive renal transplants at a single centre to study the effect of these factors in conjunction with an additional factor which we have termed the Donor Insitu Ischaemic Time (DISIT). DISIT is a new definition which has been used to describe the time from commencement of cold perfusion in the donor until the organ is removed from the body and placed on ice. The authors hypothesised that this time is another potential ischaemic period, until cellular metabolism has been fully arrested when placed on ice.

Methods: A retrospective analysis on a single centre data set containing 246 patients was conducted. The criteria for DGF was specified by patients requiring haemodialysis immediately post transplantation or having a less than 10% fall in serum creatinine in 24 hours post transplantation. A one way ANOVA was utilised to assess the correlation between DISIT and DGF.

Results: DISIT ranged from 12 minutes to 107 minutes with a mean DISIT time of 39.2 minutes. DISIT is slightly longer in in BD donors (40 mins) v DCD donors (37 minutes). DISIT time was found to be significantly correlated with the initial function of the organ (p=0.007). Further, a generalised linear model demonstrated the predictive power of DISIT time and other surgical variables on the initial outcome of the graft. These results demonstrate the importance of surgical variables on DGF.

Conclusion: Surgeons need to be aware of the impact of DISIT on renal allograft outcomes and the effect of the additional ischaemic injury period. Our further aims are to analyse longer term graft function and evaluation of protocol biopsy to analyse the effect of DISIT on kidney injury and recipient outcomes. 

Lau N, Crawford M, Pulitano C Australian National Liver Transplantation Unit, Royal Prince Alfred Hospital, Sydney

Aims: Split liver transplantation (SLT) addresses donor shortages by providing two partial grafts from a single donor liver but its use has been limited to ideal recipients due to technical challenges and a perceived increased risk profile. Arterial reconstruction using an interposition graft facilitates use of split grafts with difficult recipient anatomy but has been reported to have an increased risk of complications, and therefore remains controversial in high-risk recipients and retransplantation.

Methods: A retrospective review of the prospectively maintained Australian National Liver Transplantation Unit database was performed. We included all adults receiving a SLT between July 2002 and November 2019 and extracted donor, recipient, operative and complications data. Results: Arterial reconstruction required an interposition graft in 46/155 patients. Overall graft and patient survival were not significantly different between the groups with 1-, 3-and 5-year graft survivals of 82%, 77% and 69% for those requiring interposition grafts and 86%, 79% and 77% for those not requiring interposition grafts respectively ( Figure 1 ). There were more cut liver edge bile leaks in the interposition graft group (26% vs 9%), but there were no significant differences in the rate of biliary anastomotic leak (11% vs 11%) or stricture (13% vs 19%); hepatic artery thrombosis (7% vs 10%) or hepatic artery stenosis (13% vs 10%).

Conclusions: Interposition grafts when required for arterial reconstruction in SLT can be used safely and without increased risk of complications. This supports broadening the applicability of SLT to potentially include high-risk recipients and retransplantation. Figure 1 . Graft survival is not significantly different between those patients requiring an interposition graft and those not requiring an interposition graft during split liver transplantation. .7 respectively, the graft function was significantly improved after 1 month and 3 months (p<0.05). In a case where the brain natriuretic peptide (BNP) was measured before and after the closure, the eGFR improved as BNP decreased.

(figure)

Conclusions: The improved cardiac function possibly due to AVF closure may have had a positive impact on the kidney graft function. Given the result of an improvement trend of the graft function in the short term, with definite indications such as heart failure due to high flow AVF, painful aneurysm and aesthetic reasons, the surgical AVF closure appears to be safe and reasonable in well-functioning kidney recipients. Figure. Change of BNP and eGFR after AVF closure Comparisons were made between early and late AMR for treatments provided, response to treatment and graft (death as a competing risk) and patient survival using comparison of proportions and Cox regression models. AMR and vascular rejection were modelled with an interaction with follow-up time due to non-proportional hazards.

Results: Early AMR was treated more aggressively than late AMR with greater use of steroids, plasma exchange and monoclonal/polyclonal antibody. There was substantial variation between transplant units. Early AMR resolved with improved graft function (71%) more frequently than late (32%). From 3-months post-diagnosis, late AMR was associated with an increased risk of graft loss and death from diagnosis compared to early AMR. This association held after adjustment for multiple factors (Table 1) including eGFR at diagnosis (not shown). Conclusion: Late AMR confers a higher risk of death and graft loss than early AMR. The heterogeneity in the treatment of AMR, particularly late AMR, across Australia and New Zealand, highlights the need for high-quality trial data and effective therapeutic options for this condition. . Influenza and invasive pneumococcal disease showed significant excess cases compared with the general population (influenza SIR 8.5, 95%CI 7.8-9.2, pneumococcal SIR 9.8, 95% CI 6.9-13.9), associated with morbidity (hospitalisation rates 47-68%) and some mortality (4 deaths due to influenza, 1 death due to pneumococcal). By 10 years post-transplant, the cumulative incidence of a vaccine-preventable infection was 12% among all recipients, generally similar by organ but higher among lung recipients. Gastrointestinal infections, tuberculosis and legionellosis also had excess cases among transplant recipients (Figure 1 ). There were few sexually transmitted or vector-borne infections.

Conclusions: Common preventable infections are over-represented among transplant recipients, causing significant morbidity and health system costs. Preventive strategies should be targeted, including vaccination, food-hygiene and hand-hygiene education, and assessment for latent infection. Figure 1 . Standardised incidence ratios with 95% confidence intervals of notifiable infections after transplant ). Incidence of BPAR was higher for DGF patients but did not significantly impact 5-year graft or patient survival. There was enrichment for neutrophil adhesion and diadepesis by ingenuity pathway analysis but this did not translate to significant difference in neutrophil counts between DGF and non-DGF groups.

Conclusions: There are clear risk factors and differences in transcript signature for DGF but neutrophil count was not a useful biomarker for this application at the time the biopsy was taken. 2 patients returned to theatre for post-operative haemorrhage, and 3 for complications secondary to graft pancreatitis with 2 requiring necrosectomy. Median length of stay was 16.5 days (range 10-60). One case of CMV infection occurred in a recipient not receiving valgancyclovir prophylaxis. No cases of BK virus nephropathy occurred. There was one episode of acute rejection at 9 months due to non-compliance with immunosuppression. Patient and graft survival have been 100% with an average 6-month HbA1c of 5.2%. Conclusion: Our experience with steroid-free immunosuppression is encouraging with outcomes comparable to larger published series. There has been no added morbidity due to anti-coagulation and importantly, no graft thrombosis in this initial cohort. Figure 1A ). Relative survival remained lower among kidney transplant recipients for colorectal, melanoma, breast and prostate cancer but was comparable for lung cancer ( Figure 1B-F) . Conclusion: Relative survival was lower among kidney recipients with de-novo cancers, overall and in certain cancers such as colorectal, melanoma and breast. Decreased survival may be due to poorer access to, more harm or less efficacy of treatments.

Gauthier P, McKanna T, Aleshin A, Shchegrova S, Kalashnikova E, Ahmed E, Arbel T, Bloom M, Salari R, Swenerton R, Demko Z, Zimmermann B, Billings P Natera, Inc, USA Background : Detecting elevated levels of donor-derived cell-free DNA (dd-cfDNA) in the plasma of transplant recipients has been used as a metric to determine graft injury due to immunologic rejection. To clinically interpret the quantification of dd-cfDNA with respect to total cfDNA, we sought to investigate how various clinical and treatment-related factors may influence cfDNA levels.

Methods: Retrospective analysis of 3 different sample cohorts processed through a next generation sequencing platform: Pregnant Women (n = 205,052), Transplant Patients (n = 1,122) and Cancer Patients (n = 1,062) was performed. Analysis of association between cfDNA concentration and other variables such as patient weight, treatment status and time after surgery was performed using absolute or indirect measures of cfDNA levels (reported as arbitrary units [AU]).

Results: An elevated level of total cfDNA was observed to be associated with an increase in patient weight in pregnant women and early-stage cancer patients. Concentration of cfDNA was significantly elevated in patients receiving active treatment and in metastatic cases (P<0.0001). Additionally, major trauma such as surgery was found to significantly contribute to the increase in total cfDNA levels within 2-weeks of surgery (P<0.01).

Conclusion: cfDNA levels can be influenced by multiple factors including surgery and patient weight. Considering patient-related factors associated with changes in total cfDNA levels may improve the clinician's interpretation of dd-cfDNA results and patient outcomes.

Aslam A, Singla A, Kotecha K, Fisher C, Puttaswamy V Vascular Surgery, Royal North Shore Hospital, NSW Aims: The role of prophylactic wound drainage in renal transplantation is to reduce incidence of post-operative wound collections, haematomas or allograft dysfunction. No consensus exists on the use of drains in retroperitoneum following transplantation. The aim of this study was to assess the clinical impact of change in drain protocol at our local institution. Methods: Patients who underwent renal transplant in our unit were reviewed between 2018-2020 inclusive. Retrospective cohort series were analysed, single versus two drains. Normal protocol was to maintain drains in-situ until drain output was andlt;50mls/24 hours. The patient demographics, outcomes and allograft function was analysed. Both living and deceased donor transplants were included in the analysis. A systematic review was performed. GoogleScholar, MedLine and PubMED was reviewed with key words including "wound drainage" AND "transplantation". Results: In total, 40 patients were included in the retrospective review. Cohort 1 (2 drains) n=20, Cohort 2 (1 drain) n=20. There was no difference in incidence of post-operative wound complications or lymphoceles (4% for both cohorts p= n.s.). There was no increase in duration of drain insertion (mean length of drain insertion time 5 days p=n.s.). There was no difference in rate of delayed graft function (p=n.s.). There was very low rate of overall wound infection (2.5% in each group, n =1). A systematic review retrieved several small retrospective series, one RCT and several systematic reviews (n=12). No consensus guideline could be found on the role of retroperitoneal wound drains following transplantation. The incidence of post-operative wound complications and collections did not differ between cohorts with and without drain usage. No previous studies could be found comparing single versus two drains. No impact of drain insertion was found on allograft function, renal vein thrombosis or post-operative deep vein thrombosis. Conclusions: The insertion of two drains does not provide superiority over single drain insertion. In addition to this, the use of two drains exposes patients to the need for additional instrumentation and given that it does not provide a clinical benefit, we have changed our protocol to encourage the use of single drains.

Yoo J 1 , Brossart K 2 , Simmons W 2 , Bloom M 2 , Desai A 1 , Clevy-Schneller T 1 , Sodhi R 1 , Jain D 1 , Akkina S 1 Aims: Donor-derived cell-free DNA (dd-cfDNA) is a clinically validated non-invasive biomarker for kidney transplant (KT) rejection. Dd-cfDNA represents a percentage of the total cfDNA level. Viral infections, such as SARS-CoV-2, may influence cfDNA levels, confounding dd-cfDNA readings. SARS-CoV-2-infected KT recipients are at high-risk for allograft rejection due to reductions in immunosuppressive treatments. Methods: Dd-cfDNA and total cfDNA levels were monitored in four KT recipients, infected with SARS-CoV-2, using Prospera. Case 1: A 64-year-old male presented with pneumonia and acute kidney injury (AKI). Prednisone 5mg daily replaced mycophenolate sodium (MPS); cyclosporine levels were reduced 50%; tocilizumab was given on days 1 and 3. The patient required ventilator support but passed away 23 days after COVID-19 diagnosis. Case 2: A 52-year-old male presented with fever and dyspnea. MPS was replaced by prednisone 10mg daily. Despite receiving Remdesivir for 5 days. The patient was intubated but passed away 26 days after COVID-19 diagnosis. Case 3: A 66-year-old female was hospitalized for respiratory distress 10 days after COVID-19 diagnosis. Remdesivir was administered for 5 days; MPS was replaced by prednisone 5mg daily. The patient was discharged after 4 days. Case 4: A 61-year-old female was hospitalized for fall, hypotension, AKI. Increase in prednisone substituted MPS. AKI resolved and the patient was discharged.

Conclusions: In the presented cases, dd-cfDNA fractions were <1.0% and accompanied by highly elevated total cfDNA levels. Accounting for variation in total cfDNA may be important for accurate interpretation of dd-cfDNA results and assessment of allograft rejection in individuals with COVID-19. Secondary and tertiary hyperparathyroidism are major complications of chronic renal failure, and can persist following renal transplantation. The optimal surgical treatment of renal hyperparathyroidism is uncertain. We examined our experience with an audit of consecutive cases at our centre. In a single-centre retrospective audit of a 10 year period, we compared outcomes between total parathyroidectomy with autograft and subtotal parathyroidectomy. The theatre database ORMIS was utilised to capture all parathyroidectomies over the study period, with this list filtered for operations performed for renal hyperparathyroidism. Patient records were accessed to determine reason for referral (secondary/tertiary hyperparathyroidism), dialysis/transplant status, type of operation, weight of resected tissue, duration of post-operative calcium infusion, length of stay (LOS), calcium and parathyroid hormone (PTH) trends and complications. These data were compared between groups, with exclusion of MIP and re-exploration operations. Of all patients undergoing parathyroidectomy for renal hyperparathyroidism (n=78), the majority were performed for tertiary hyperparathyroidism. 42% had functioning transplants or required definitive management of hyperparathyroidism before being waitlisted for transplantation. 55 patients underwent subtotal parathyroidectomy and 23 had total parathyroidectomy with autograft, with the remainder undergoing MIP or re-exploration. Median LOS was significantly less in the subtotal parathyroidectomy group (4 days vs 6 days in total parathyroidectomy, p=0.029), with a trend toward shorter duration of post-operative calcium infusion. There was no significant difference in the post-operative calcium and PTH levels over time. Subtotal parathyroidectomy is not inferior to total parathyroidectomy with autograft, and may result in shorter duration of post-operative calcium infusion and LOS. Aim: Splenic artery aneurysms (SAA), although rare in general population, occur more commonly in liver transplant (LT) candidates and are at heightened risks of rupture with potentially fatal consequences. As optimal management of this condition remained undetermined, we aimed to present the first systematic review on this topic. Methods: We performed a systematic review of the literature to investigate the management options and outcomes of asymptomatic SAAs in liver transplant candidates. EMBASE, MEDLINE electronic databases were used to identify articles. The inclusion criteria used were articles published in English which reported on the management of SAAs diagnosed pre-transplant and their outcomes following LT. Results: 11 articles were selected for analysis and included 168 patients with SAA, amongst which 121 had asymptomatic SAA diagnosed pre-LT and had LT. Majority of SAA was located distally or intra-hilar (73%) and up to 44% of patients had multiple SAAs. In 121 patients diagnosed pre-LT, 34 patients had treatment instigated (25 treated surgically and 9 treated radiologically). Post-LT rupture was noted in 2 patients treated surgically (no fatality). No rupture was observed in radiologically treated group, although 1 patient died from splenic abscess and sepsis following embolisation. In 87 untreated patients, 4 post LT rupture was recorded (3/4 resulted in fatality). Conclusions: Although mostly asymptomatic, SAAs are at heightened risks of fatal rupture post LT and treatment should be considered. Both surgical and radiological treatments offer adequate control and choice of treatment is dependent of location and number of SAA present.

Aim: Extracorporeal membranous oxygenation (ECMO) is used to provide prolonged cardiopulmonary support to the critically ill. Unfortunately, a significant number of patients fail to wean from ECMO, providing an added opportunity for organ donation. Our aim is to systematically review the outcomes for renal transplantation from donors that were receiving ECMO support prior to organ retrieval. Methods: A systematic search was conducted from MEDLINE, EMBASE and CENTRAL databases for studies involving renal transplantation of kidney allografts from ECMO-dependent donors prior to death. Identified studies were screened for inclusion criteria and the quality of evidence was assessed accordingly. Results: Five studies describing 170 kidney transplant recipients from 113 donors requiring ECMO were identified. Of these, 100 transplants were from DBD retrievals and 13 from DCD retrievals. The average 1-year kidney allograft survival from ECMO donors was 92%, which showed no differences when matched with recipients from donors without ECMO (p = 0.24-0.98). Average renal function at 1-year was 1.62 mg/dL and delayed graft function was reported to be between 34% and 42.9%. Overall risk of bias is low and the quality of evidence is low or very low for all studies. Conclusions: Our review shows that recipients undergoing renal transplantation from donor kidneys requiring ECMO have normal renal function after 1-year and equivalent 1-year graft survival when compared to renal transplantation from standard criteria donors. Further investigation into the outcomes of transplantation from ECMO supported donors is needed to clarify whether patients requiring ECMO support remain a suitable cohort for retrieval.

Case: 32-year-old female with a past history of ESRF secondary to IgA nephritis presented with severe diarrhoea 11 months after a non-complicated LR kidney transplant. She was on standard immunosuppression with prednisone, myfortic and tacrolimus. Her creatinine had increased from a base line of 126 µmol/l, eGFR 49 to 204, eGFR 27 with high tacrolimus level of 29 µgm/l. Stool cultures were positive for Sapovirus which from the literature is difficult to treat without reduction or cessation of mycophenolyate. It is associated with prolonged viral shedding often > 300 days. She was given a course of nitazoxide over 3 days with rapid resolution of her diarrhoea and a return to baseline creatinine without reduction of her immunosuppression. Her stool culture had rapid resolution of Sapovirus PCR This case adds to a very limited literature using of nitazoxide in transplantation and is possibly the first case of Sapovirus successfully treated with nitazoxide without reduction of immunosuppression.

Background: We report two rare complications of simultaneous pancreas-kidney transplantation (SPKT) occurring in one patient. Case report: A 39-year-old man with end-stage renal failure secondary to type 1 diabetes mellitus underwent successful SPKT in October 2018. Three months later, he presented with acute kidney injury (AKI) and returned to dialysis. Renal scintigraphy showed a central photopaenic region and angiogram showed absent flow in the renal transplant artery without treatable thrombus and the incidental finding of two pseudoaneurysms of the pancreatic Y-graft. He remained dialysis-dependent for three weeks before spontaneous partial recovery of allograft function; repeat renal scintigraphy showed significant improvement in perfusion. However, in April 2019 he was readmitted with a sudden deterioration in renal allograft function again necessitating haemodialysis. Clinical examination and renal scintigraphy confirmed that the renal allograft had shifted from the left iliac fossa to the midline. He underwent surgical exploration during which torsion of the renal allograft was confirmed and nephropexy performed. The kidney allograft was originally implanted in the left retroperitoneum via a midline transperitoneal approach, which likely predisposes it to torsion. The pseudoaneurysms of the pancreatic Y-graft were managed conservatively and surveillance imaging demonstrated that they had not increased in size. The patient regained reasonable renal allograft function (estimated glomerular filtration rate 48mL/min) and maintains normal pancreatic allograft function. Conclusion: Renal allograft torsion should be considered post-SPKT in patients with AKI and absent or minimal arterial flow. Although most published case reports describe surgical management of pseudoaneurysms post-SPKT, our case demonstrates successful conservative management.

Hewa-Geeganage S 1 , Diolombi M 2 , Kanagarajah V 1 , Lockwood D 1 , Preston J 1 , Wood S 1 , Lawson M 1 , Ray M 1 , Tan AL 1 , Griffin A 1 , Rhee H 1 1 Renal Transplant Unit, Princess Alexandra Hospital, Brisbane, 2 University of Queensland, Aims: The increasing waitlist for kidney transplantation and shortage of donor organs is an ongoing issue. Strategies to expand the donor pool include use of dual kidney transplantation from donors at extremes of age. Expanded criteria allow use of older kidneys, and although technically challenging, en bloc paediatric kidneys have similar graft survival rates to adult deceased donor single kidney transplants. We examined the outcomes of two-in-one and en bloc paediatric kidneys in adult recipients across a 25-year period in our tertiary referral centre. Methods: A retrospective review was undertaken of transplant recipients of two-in-one adult kidneys or paediatric en bloc kidneys at Princess Alexandra Hospital between May 1994 and June 2020. Demographic data, creatinine at 3, 6, 12, and 60 months, technical and medical complications, and graft survival were analysed through medical records. Results: Forty-eight patients received dual allocation kidneys. The average creatinine at 1 and 5 years was 117μmol/L and 90μmol/L, respectively. Only one graft was lost due to vascular complications (2%). Two others developed non-graft threatening thromboses requiring anticoagulation. Five grafts were lost to rejection or early disease recurrence (10.8%). Ureteric complications saw one en bloc graft lost 5 years post-transplant. Conclusion: Two-in-one or en bloc kidney transplants have a role in transplant units. Marginal donor kidneys function comparably to non-marginal single kidney transplants; at 5 years, the mean creatinine was 90μmol/L. Technical aspects are to be considered, including vascular complications and torsion of en bloc kidneys. Overall, the results are acceptable, and provides support for programmes to expand donor criteria.

Aim: To assess the results of kidney re-transplantation performed at Hue Central Hospital, Vietnam. Methods: 985 kidney transplants have been performed at a single hospital since July 2001, all with living donor grafts. 41(4,2%) were second kidney transplants performed between 2012 and October 2020. Cross matching used to by CDC technique, it is replaced with FCXM in Hue and histopathology specimens were forwarded to HCMC, 90 minutes flight time away. All recipients received the same immunosuppressive regimen with induction therapy of ATG or Basiliximab and maintenance therapy of tacrolimus, MMF and steroids. CMV prophylaxis with Acyclovir was applied for 41/41 (D (+) and R (+)). Long term follow-up in Vietnam is mandated in order to receive subsidized oral immunosuppressive agents. Results: Average recipient age was 44+/-9 years, 31 were male and 10 were female. 7 recipients had initial primary graft survival of >5 years. 12 (29.3%) were HCV positive. 36 (87,81%) recipients had at least 3 HLA matches. 3 cases of acute rejection responded to treatment. All were sensitized, ABO compatible, with 29 having PRA <25%, and 2 >80%. All grafts had primary function and graft survival at one year was 100% (41/41) and five years (7/7). Graft is summarized in attached Aims: Dual kidney transplantation is a recognised technique to maximise transplanted nephronic mass from expanded criteria donor kidneys (ECD). Significant heterogeneity have been reported in short and long-term allograft outcomes. This study will to assess the surgical outcomes in patients who have undergone bilateral kidney transplantation at Royal North Shore Hospital from January 1, 2010 to December 31, 2019. Methods: Patients have been retrospectively identified using the transplant database in a single institution from 2010-2020 inclusive. Patient characteristics, surgical technique and allograft characteristics were reviewed. Outcomes were reviewed in terms of patient complications and graft function. Results In total, 245 transplants have been performed in the studied time-frame. The incidence of dual kidney transplantation was 4.5% (n=11). The mean warm ischaemia time (WIT) was 84.5minutes. The mean cold ischaemia time (CIT) was 811.7 minutes. The mean donor age was 69 years old. Majority of the patients had bilateral transplantation (n=10), with one patient undergoing unilateral placement of both kidneys. All patients received similar induction therapy (ATG/basiliximab) and maintenance therapy (standard triple medication).Minority of patients had immediate graft function of 18% (n=2), the remaining 88% (n=9) displaying delayed graft function.

Of those with delayed function, one patient had partial graft loss (unilateral nephrectomy), one had complete graft loss (bilateral nephrectomy). Complete graft loss was secondary to hyper-acute rejection in that patient. 3 of the 11 patients displayed signs of rejection in immediate post-operative phase, with 2/3 responding to anti-rejection therapy. 36.3% (4 out of 11) patients have been noted to be requiring dialysis in their latest follow up. The average creatinine (micromole/L) level for this group of patients was 274.19 at mean of 1856.27 days of follow up postoperatively. Conclusions: Dual kidney transplantation is a recognised means for expanding the donor pool in renal transplantation. We have noted the high incidence of delayed graft function and unsuccessful transplantation in this cohort of patients. Further studies would be required to assess outcomes in this group of patients.

Tharmaraj D 1 , Barraclough N 2 , Kanellis J 1 1 Department of Nephrology, Monash Medical Centre, Melbourne, 2 Department of Nephrology, South West Health Care

Background: Rabbit derived anti-thymocyte globulin (ATG) is used to treat allograft rejection. Serum sickness is an immune-complex mediated hypersensitivity reaction and is a known complication of ATG usually manifesting 7-14 days following therapy. Circulating antigen-antibody complex deposition and complement activation leads to systemic tissue injury. Previous rabbit exposure is a reported risk factor Case Reports: A 45 yo male presented with high fevers, migratory polyarthritis, jaw pain, and rash, 8 days following ATG therapy for pancreas transplant rejection. Investigations revealed an elevated C-reactive protein (CRP) of 377 mg/L (0-5) and suppressed complements C3-0.71g/L (0.8-1.50), C4-0.05g/L (0.16-0.38). His daughter had a pet rabbit. The second case was a 40 yo male who presented with migratory polyarthritis, myalgias, fevers and jaw pain, 7 days following treatment with ATG for pancreas transplant rejection. His family owned a rabbit farm during his childhood. He had suggestive markers of elevated CRP-138mg/L, and suppressed C3-0.78g/L and C4-0.08g/L. Both cases were successfully treated with intravenous hydrocortisone for three days followed by weaning doses of oral prednisolone over 2-weeks. CRP and complements normalised prior to discharge. The rabbit was able to remain in the family in the first case. Conclusion: Serum sickness is an important complication to consider following treatment with ATG, particularly with a history of rabbit exposure and characteristic clinical and biochemical features including jaw pain, migratory arthritis, fevers, rash, elevated inflammatory markers (CRP), and suppressed complements.

Aims: Living organ donation does not impact survival however, the lived experience and health utilisation of donors after donation is less understood. We sought to evaluate hospital admissions among living donors following donation.

Methods: We included all solid-organ living donors who donated in NSW, 2004-2015, using the NSW Biovigilance Public Health Register (SAFEBOD), linking donors and recipients to administrative health databases. We evaluated all hospitalisations after donation and estimated incidence rate ratios (IRR) relative to hospitalisation rates in the NSW general population, adjusting for age, sex and year. Results: Of 966 living donors, 99% donated a kidney and median age at donation was 48 years. Hospitalisation for organ donation was <5days for most (65%) and 5-9days for one-third of donors, with only 2% in hospital for ≥10days. Over the 7,470 person-years follow-up post-donation (median 8.0 years), there were 13 deaths and 2,745 hospitalisations including 1,393 emergency presentations. Relative to the general population, hospitalisation rates were 70% higher than expected in the first 3 months post-donation (IRR:1.71; 95%CI: 1.29-2.26) and, at any given time, were twice that expected for males aged 18-34 years (IRR:2.11; 95%CI:1.53-2.90). Hospitalisation rates were similar or lower than expected for donors who were female, aged ≥35 years or after 3 months post-donation (Figure 1 ). No excess hospitalisations were seen over calendar period. Conclusions: Hospital utilisation was greater than expected among young men and <3 months post-donation. After 3 months post-donation, living organ donors did not have increased hospital use, supporting the safety of live organ donation. (Table) . For 2007-2009 cohort proportion of patients on W/L at 3, 6 and 12 months was similar between Victorian and non-Victorian groups. From 2009 onwards there was a progressive improvement for Victorian patients to 2016-2018 compared to non-Victorian patients (Table) . There was no significant change for non-Victorian patients on W/L at 3, 6 and 12 months over the eight-year study period. Conclusion: Victorian KPI were associated with a progressive reduction in median time to W/L and greater proportion of dialysis patients on W/L. Indigenous Victorians appear to have also benefited but to a lesser degree and over a greater time-period. Consideration should be given to establishing National KPI's. 

Aims: Large-scale studies of cancer transmission from donors to recipients are sparse. We sought to identify any cases of cancer transmission or non-transmission from transplantation in a cohort of NSW donors and recipients. Methods: We included all NSW resident solid organ donors and recipients from 2000-2012 in a cohort study using linked data from the NSW Biovigilance Public Health Register (SAFEBOD). Linked data from the Central Cancer Registry (CCR) was available to 2013 (minimum one-year follow-up). Donor-recipient pairs (transplants) were classified as having likely, possible, or excluded transmission events using international guidelines. Non-transmissions were recipients with transmission excluded, but where the donor either had a cancer history in the CCR or a possible/likely transmission to another recipient. All other transplants were non-events.

Results: In our cohort 2,530 recipients underwent 2,572 transplants, 1,828 (71%) deceased donor and 744 (29%) living. We found 4 (andlt;1%) transmissions from deceased donors (2 likely, 2 possible), and 1 (andlt;1%) possible transmission from a living donor (Figure 1 ). Four transmissions were from donor kidney cancers found and excised during retrieval, while one was a family reported cancer of unknown site that could not be verified in the CCR. The 4 deceased donors involved in transmissions donated to 10 recipients with 4 transmissions and 6 non-transmissions. Overall, 61 (2%) non-transmissions occurred (55 with donor cancer history, 6 from donors who transmitted to a different recipient).

Conclusions: Cancer transmission from transplantation is rare, and donors with a cancer history may be safe to transplant. Aims: The Australian deceased donor (DD) kidney transplant program places a large emphasis on HLA matching despite a known disadvantage to racial minority groups. We sought to assess the clinical outcomes of the current allocation model, and its impact on racial minority groups. Methods: A retrospective cohort analysis of adult DD kidney transplants from 2000-2018 using ANZDATA records was conducted. Transplants were divided into "Matched" or "Waitlist" allocation groups based on the OrganMatch score, transplant state, and the current TSANZ allocation algorithms. figure) . Triglyceride levels decreased early following transplant but were stable over five years of follow-up. HDL levels increased significantly at three (pandlt;0.01) and five years (pandlt;0.01) post-transplant. However, no significant changes were observed in total cholesterol, LDL or uACR over the follow-up period.

Conclusions: SPK recipients experience significant weight gain despite improvements in lipid profile post-transplant. Further work will involve analysis of outcomes over a more extended follow-up period to evaluate discrepancies in this metabolic picture. Aims: We aimed to conduct a systemic review investigating the prevalence and outcomes of the use of burns victims, as a source of organ donation. Methods: PubMed and MEDLINE databases were utilised, with searches conducted between 1990 -2020, using keywordsorgan procurement, organ donation, organ transplantation, and burns. Studies were not excluded based on patient numbers and included both published abstracts/conference proceeding and journal articles. Studies were excluded if specific organs were not identified or if post-transplant outcomes were not recorded.

Results: Upon reviewing 437 articles, 7 manuscripts met inclusion criteria, published between 1995 -2019. A total of 15 patients identified undergoing organ donation following burn injury with total body surface area (TBSA) burn of between 4 -90% were recorded in these patients, from both donation after circulatory death or donation after brain death pathways. A total of 5 hearts, 2 lungs, 9 livers, 1 pancreas and 26 kidneys were transplanted with varying duration of follow up and outcomes (Table 1) .

Conclusion: Studies suggest that post-transplanted organs such as heart and lungs provide good outcomes, as patients were alive at time of follow-up. Although 26 kidney transplants have been performed from donors with an associated burn injury, no published article has commented on the incidence of delayed graft function or short or long term function, so recommendations for the utilisation of burns victims as multi-organ donors remain guarded. Results: Genes upregulated during active viral infection were indicative of a strong inflammatory response. Although most returned to pre-CMV levels, several genes continued to be elevated, suggesting chronic immune activation. Interestingly, genes associated with airway remodelling, tissue damage and structural alterations associated with graft damage were also elevated during CMV. Intriguingly, genes associated with the promotion of fibrosis and graft damage continued to be upregulated even after CMV replication subsided. Conclusions: Our data indicates that CMV induces a molecular phenotype in the lung allograft that is persistent and indicative of immune cell activation that can potentially lead to permanent tissue damage. These findings may identify early molecular markers associated with CLAD, thereby providing opportunities to offer early therapeutic interventions and improving lung transplant outcomes. Aims: T follicular helper cells (Tfh) and B memory cells have been associated with donor-specific antibodies (DSA) and implicated in antibody-mediated rejection (ABMR). We sought to compare immune cell subsets in patients who developed ABMR with those that did not in a well described clinical cohort. Methods: We compared immune cell subsets in 9 deceased donor kidney transplant recipients with ABMR against age-and sex-matched Stable recipients with no rejection. Pre-and 3-month post-transplant samples were immunophenotyped in a 40-monoclonal-antibody panel using cytometry by time-of-flight. Immune cell subsets were manually gated using FloJo and proportions compared using significance analysis for microarray (5%FDR).

Results: In the 9 recipients that developed ABMR (4 women, median age-at-transplant 47 years), 5 had pre-transplant DSA for which 4 received desensitisation therapy, and 4 developed de-novo-DSA. None experienced T-cell mediated rejection. Median time to ABMR was 41 days (IQR=10-358), 5/9 ABMR recipients experienced rejection within 3-months post-transplant. Of the 9 Stable recipients (4 women, median-age-at-transplant 48 years), 5 had pre-transplant DSA for which 2 received desensitisation therapy, and 3 developed de-novo-DSA. We found lower proportions of central memory Tfh (CD3+CD4+CD25-CD45RO+CXCR5+CCR7hiPD1lo), Th17-like Tfh (CD3+CXCR5+CXCR3-CCR6+) and B memory (CD19+CD20+CD27+) cells in ABMR compared to Stable recipient pre-transplant samples (Figure 1 ). Tfh cells fell in the Stable group at 3-months post-transplant but did not fall in ABMR recipients. Conclusions: Despite lower levels pre-transplant, Tfh cells were maintained post-transplant in recipients that developed ABMR which may suggest a persistence of Tfh cell subsets in recipients that are susceptible to ABMR. Figure 1 . Cell surface microarray of pre-transplant samples comparing patients who developed ABMR with Stable kidney transplant recipients

Note: Forty T and B cell subsets were profiled and compared across recipient samples between ABMR (orange) and Stable (pale blue) recipients. Cell subsets (rows) that are significantly different between recipients (columns) are shown in the graph above where standardised change in expression of subsets is graded in a z-score from decreased expression (-2, blue) to increased expression (2, yellow). False detection rate was set at 0.5.

Bampton T 1 , Palmer L 2 , Coates T 3 1 University of Adelaide, 2 School of Public Health, University of Adelaide, 3 Central Northern Adelaide Renal and Transplantation Service, Royal Adelaide Hospital Introduction: Chronic Panreatitis (CP) in the paediatric population is a rare condition, often inherited, with disabling impacts on education and a high risk of negative sequalae continuing into adulthood. Total pancreatectomy and islet autotransplantation (TP-IAT) is a novel procedure that may benefit selected individuals with CP. Aims: 1) Investigate the epidemiology of CP in the paediatric population of South Australia (SA), 2) Estimate the burden of paediatric CP on SA healthcare and 3) Estimate the impact of CP on education.

Methods: The index cohort consisted of all individuals having a first diagnosis of CP aged ≤19 years in SA public hospitals from 1/6/2000 to 30/6/2019. Age-and sex-matched controls were drawn from the general population as well as from individuals who were diagnosed with type 1 and 2 diabetes mellitus during the same period.

Results: A total of 73 index cases were identified. Crude prevalence and incidence of paediatric CP were estimated at ~6.8/100,000 and ~0.98/100,000 respectively. Of the index cohort, 24 (32.8%) of cases of paediatric CP self-identified as Aboriginal or Torres Strait Islander. The case group averaged 11-fold more hospital visits, ~5-fold more emergency department visits and ~10-fold more days in hospital than the general public (all P <0.001). The index cohort averaged two-fold higher rates of absence from education than the general public (P <0.001).

Conclusion: Paediatric CP patients consume a high volume of public health services and are significantly impacted in ability to engage in education. Selected inviduals within this group may be candidates for TP-IAT.

Background: Dyskeratosis congenita (DC) is a rare, inherited, progressive, and multi-system disease of aberrant telomere maintenance. Significant morbidity and mortality arise from bone marrow failure, haematological malignancies, solid tumours, pulmonary fibrosis, and liver disease. The classical mucocutaneous clinical triad seen in 80-90% consists of dysplastic nails, lacy reticulated skin pigmentation, and oral leukoplakia. In DC, organ transplantation including lung, liver and haematopoietic stem cell transplants are life-saving interventions.

Case Report: We report on the first case of DC treated with simultaneous liver and kidney transplantation after prior bilateral lung transplantation for hepatopulmonary syndrome and pulmonary fibrosis. The diagnosis of DC was established by the detection of a pathogenic TERT gene variant and measurement of telomere length <1 st percentile for age. The aetiology of kidney failure requiring dialysis was thought to be multifactorial, including calcineurin inhibitor toxicity, steroid-induced diabetes, and cirrhosis-related glomerulonephritis. The lung transplant was complicated by post-operative atrial fibrillation, multi-lobar pneumonia, and restrictive tuberculous pericarditis requiring pericardiectomy. The combined kidney and liver transplant were complicated by low-grade CMV viraemia, cytopenia, and mixed rejection. An eGFR of 76 ml/min and satisfactory liver function was achieved ten months post-transplant. Pancytopenia present before the combined liver-kidney transplant has resolved, but an allogenic bone marrow transplantation is likely in future given the natural history of DC. Conclusion: Multi-organ transplantation is increasingly used to prolong life for the progressive genetic disease dyskeratosis congenita. This case provides a unique example of the challenges of multi-organ failure and the multi-disciplinary involvement required for this condition. Results: The recruitment process has identified a significant shortage of ATSIHP with only 1 ATSIHP recruited, commencing on 14 December 2020. Conclusions: The employment of an ATSIHP is seen as an essential role which needs to be included within the transplant team to further promote cultural safety and bridge the cultural Gap in order to improve Indigenous Australians access to and outcomes of kidney transplantation. We anticipate that we will achieve the intended outcomes with the next 12 months. Background: The numbers and characteristics of the abstracts presented at the Annual Scientific Meetings (ASM) of the Transplantation Society of Australia and New Zealand (TSANZ) that are converted to peer-reviewed publications have not previously been analysed. Methods: All abstracts presented at the TSANZ ASM from 2013-2017 were reviewed. A literature search was performed using a search algorithm to identify the full-text publications of the presented abstracts. Correlation between abstract characteristics and publication rate was then examined using Cox proportional hazards regression and Kaplan-Meier curves to distinguish the predictors for publication. Results: Over the 5-year period, 576 abstracts were presented, with a total of 164 (28.6%) presentations converted to publications. The majority of presentations occurred within the first 3 years, with the mean time to publication being 16.6 (SD = 14.6) months. The median impact factor for published research was 4.74 (IQR=3.06-5.58). Multivariate analysis identified clinical science papers, systematic reviews and surveys (LR=1.42, 5.02 and 2.01;p=0.040, 0.000 and 0.010 respectively) as the most important predictors for publication.

Conclusions: The rate of abstracts presented at the TSANZ ASM over 5 years that were converted to publication in a peer-review journal was 28.6%. Clinical papers, systematic reviews and surveys were more likely to be published. An ongoing strict abstract selection process will contribute to improving conversion of abstracts into full-text peer reviewed articles Aims: Robotic-assisted Kidney Transplantation (RAKT) may offer a path to transplantation for patients with high Body Mass Index (BMI). Currently lacking is an appropriate model for simulation training. We report an experimentally developed technique for heterotopic renal transplantation using a large animal model mimicking RAKT in humans. Methods: Following ethics approval, four Landrace pigs were acquired. A robotic-assisted left nephrectomy was performed, the kidney was perfused with University of Wisconsin (UW) preservation solution and stored in ice. Four robotic ports (3 x 8mm and 1 x 12mm) were placed across the abdomen (Fig. 1) . A suprapubic hand-port was inserted and a 10mm assistant port placed on the left between robotic ports. After introducing the kidney via the hand-port, the renal vessels were anastomosed to the external iliac vessels and the ureter to the bladder over a stent using the DaVinci Xi surgical robot (Intuitive Inc. Sunnyvale CA, USA). The pigs were euthanised on completion.

Results: After an initial unsuccessful attempt, the technique was refined by variation of port placement. Three successful concurrent RAKTs were performed with urine output observed. Mean time both anastomoses was 67.5 minutes, in line with published literature.

The learning curve for this operation in humans is between 5-19 cases. No method of accomplishing robotic-assisted heterotopic autotransplantation in a large animal model has been previously described. This translational model for training is hypothesised to shorten the learning curve of operators and the team as a step to adopting this procedure in humans without compromising safety. Figure. Port placement for robotic-assisted heterotopic renal transplantation in a porcine model

Methods: All eplet mismatches at HLA class I and II loci were calculated for each donor and recipient pair in a cohort of consecutive adult simultaneous pancreas-kidney (SPK) transplant recipients from 2005-2017. Cox regression (regularized and proportional hazards) models, adjusted for donor and recipient characteristics and presence of pre-transplant DSA, were utilized to determine the association between specific eplet mismatches and biopsy proven acute rejection outcomes. Results: 202 recipients of a first SPK transplant (mean age (SD) 39.1 (7.0) years) were followed for a median (IQR) of 3.9 (5.7) years. Overall, 30% (60/202) developed acute cellular and/or antibody mediated rejection at a median (IQR) time of 0.1 (0.9) years post transplantation. Recipients with class I eplet mismatches at 163EW, 156WA, 62EE, 16S, 211T, 144QL or 102HV experienced an approximately double or higher risk of acute rejection, compared to those without mismatches. Recipients with class II eplet mismatches at 67L, 4Q, 40ERV, 75IL, 57V, 25Q, 185I, 66IT, 160S or 160AD experienced a similar double or higher risk of acute rejection, compared to those without these specific eplet mismatches. Conclusion: Specific class I and II eplet mismatches predict acute rejection outcomes after SPK transplantation

Melbourne Background: Cold agglutinins are antibodies that cause red cell agglutination and may cause haemolysis when exposed to temperatures below their thermal amplitude. Reperfusion of an organ removed from cold storage below this temperature may cause haemolytic anaemia and graft thrombosis. Case Report: Non-specific cold agglutinins (without haemolysis or cold-induced symptoms) were identified in a 69-year-old on peritoneal dialysis during transplant workup. Thermal amplitude was 22°C. Triple positive anti-phospholipid antibodies were also detected (anti-β2 glycoprotein-1 IgG (β2GP1), anti-cardiolipin IgG (ACA), lupus anticoagulant (LA)), with no history of thromboses or miscarriages. She underwent donation after brain death kidney transplantation (KDPI 69%, terminal creatinine 69µmmol/L) without peri-operative plasma exchange. The kidney was intra-arterially warmed and perfused with 550mL of 40°C 0.9% saline in the body cavity prior to clamp release. Laser thermometer surface temperature reached 30.5°C in 3 minutes, and reperfusion was established at 8 minutes. Cold and warm ischaemia times were 5 hours, and 41 minutes, respectively. Immediate graft function was achieved. Despite low-dose aspirin and prophylactic unfractionated heparin, symptomatic left segmental pulmonary embolus was diagnosed on day 4. At 5 weeks post-transplant, ACA remained weakly positive while LA and β2GP1 were no longer detected. Serum creatinine was 115 µmmol/L at 8 weeks. Conclusion: Successful deceased donor kidney transplantation was achieved in the presence of cold agglutinins and triple anti

Aims: Deceased donor assessment is time-sensitive and medical history often relies on imperfect information. Misclassification of skin cancers at referral may lead to missed opportunities in organ donation or harm. We sought to compare melanoma history suspected at referral with cancer records. Methods: For all deceased-donor referrals in NSW, 2010-2015, we linked Organ and Tissue Donation Service (OTDS) logs with the Central Cancer Registry (CCR), reporting cancers notified in NSW, 1976 NSW, -2013 in-situ melanomas. We compared suspected melanoma in OTDS referrals with verified melanoma notifications in CCR. Melanoma (C43) and melanoma in-situ (D03) were identified using ICD-10-AM. Suspected and verified melanomas were compared and cross-tabulated against donation outcomes. Results: Of 2, 974 referrals, 25(andlt;1%) had suspected melanoma ( Figure 1 ). Of these, only 8/25 (32%) were registered as melanomas in CCR. None of these referrals proceeded to donation. There were thus 17/25 (68%) suspected melanomas with no matching CCR record. Of these, 12/17 were declined as donors for melanoma risk alone but could have safely donated. Acceptance of these donors would have increased the 2010-2015 donor pool by 2%. Additionally, 13/2,949 (andlt;1%) referrals not suspected to have had melanomas by OTDS had verified melanoma recorded in CCR). Of these, 2/13 donated at least 1 solid organ; both donors had in-situ melanomas, with no evidence of transmission to recipients (median follow-up 14 years; IQR12.3-15.3). Conclusion: Including CCR records in the donor referral process may aid in melanoma risk classification at the time of donation and identify more opportunities for donation. FIGURE 1. Organ donor referrals suspected of melanoma which were verified (green), unverified (blue) or unknown at the time of donor referral (orange) in NSW 2010-2015 with donation outcomes. (NSW, New South Wales) Aims: Kidneys from very small donors have the potential to significantly expand the donor pool. We describe the collective experience of transplantation using kidneys from donors aged ≤1year in Australian and New Zealand.Methods: The ANZDATA registry was analysed on all deceased donor kidney transplants from donors aged ≤1year. We compared recipient characteristics and outcomes between 1963 to 1999 and 2000 to 2018 . Results: From 1963 -1999 transplants were performed (9(56%) adults, 7(44%) children). Donor and recipient characteristics are shown in table 1. Death-censored graft survival was 50% and 43% at 1 and 5 years, respectively. Patient survival was 90% and 87% at 1 and 5 years, respectively. From 2000-2018, 26 transplants were performed (25(96%) adults, 1(4%) children). Mean creatinine was 73µmol/L+/-49 at 5 years. Death-censored graft survival was 85% at 1 and 5 years. Patient survival was 100% at 1 and 5 years. Incidence of delayed graft function (DGF) was 15% from 2000-2018; data for DGF was largely missing for 1963-1999. Thrombosis was the cause of graft loss in 12% of recipients in the first era from 1963-1999, and 8% of recipients in the second era from 2000-2018. Conclusions: We advocate the judicious use of these small paediatric grafts from donors ≤ 1year old. Meticulous surgical technique and careful monitoring of clinical course, especially in the early postoperative period, is the key to good long term graft outcomes. We encourage strategies to reduce discard of this precious resource as well as techniques to reduce early graft loss. 

Child recipient (1963 ( -1999 ( ) Child recipient (2000 ( -2018 Adult recipient (1963 ( -1999 ( ) Adult recipient (2000 ( -2018 n 7 1 9 25Donor weight, median (IQR) 14 (12, 15) 10 (10, 10) 12 (10, 15) 11 (10, 12) 3 (50%) 0 (0%) 4 (50%) 6 (24%) 3 (50%) Infection (5% vs 3%) was uncommon in both groups. The largest differences in contraindications were "Other comorbidity" (26 vs 18%), and "Other" (29 vs 19%).

The results demonstrate a substantial proportion of the difference in waitlisting is attributable to health related issues. Improving access to transplantation will require a focus on addressing these issues. The large proportion of "other" contraindications reported among Indigenous patients raises issues that require further investigation.Aim: To determine whether it is appropriate to screen for advanced colorectal neoplasia with immunochemical faecal occult blood testing (iFOBT) for human haemoglobin in the renal transplant population.Method: The screening period for this retrospective study was from 1 st July 2014 to 30 th June 2019 on renal transplant recipients who were invited to attend the wellness clinic conducted by a Nurse Practitioner. iFOBT x2 during that time period were requested on an annual basis for those patients who attended the wellness clinic. Renal transplant recipients with positive iFOBT were referred for colonoscopy. Advanced colorectal neoplasia was defined as an adenoma of at least 10 mm in diameter, villous features, high-grade dysplasia or colorectal cancer. Results: 44% (n=103) of prevalent renal transplant recipients attended the wellness clinic. Baseline characteristic were 84% (n=63) male, with a mean age of being transplanted at 50 years old and 7.17 years post renal transplant. 66% (n=68) of this subgroup underwent iFOBT x2 on at least one occasion. 33.8% (n=23) of initial iFOBTs were found to be positive and were referred for colonoscopy. 69.5% (n=16) had colonoscopies. Of those, 12.5% (n=2) revealed advanced colorectal neoplasia, 25% (n=4) had non-advanced colorectal neoplasia and the remainder 62.5% (n=10) with normal or insignificant pathology. One patient within the normal subgroup developed colorectal cancer within two years after iFOBT screening and colonoscopy. Conclusion: Screening for advanced colorectal neoplasia post renal transplantation with iFOBT may be considered worthwhile in this at-risk population.

Hall H, Ross L, Croker D, Henwood P, Wilkshire N, Misener M Panuku, Purple House National Indigenous Kidney Transplant Taskforce (NIKTT) Equity and Access Initiative project AimsEstablish a specialised kidney transplant support team withing the Purple House -Panuku model of care. The 'hunting' team consists of a team of well patient mentors with extensive lived experience of the kidney disease journey and a clinical health professional partner. The Hunting Transplant team will seek out positive and culturally safe collaborations across service provider, community and family networks with the aim of finding 'The Right Way' "to support a targeted group of people (6 -8) to get on the Hunt for a kidney transplant.Methods: Recruit and support specialised mentor positions to work within a participatory action research or community driven approach to develop culturally safe methods and priorities for the project. Utilise existing community relationships and networks to provide health promotion and education to family and community members. Approach includes working with patients seeking kidney transplant, partnering with TEHS Transplant education sessions, providing community-based information sessions and reporting back to community decision makers. Use a mixed methods approach to meet the mainstream or standard requirement for kidney transplant work up process. Following the clinical requirements but also working with patients and community to identify barriers and possible solutions. Measures were further grouped into 32 outcomes based on site of infection (14 outcomes) and organism (18 outcomes). The most commonly reported site-specific outcome and organism-specific outcome was systemic infection (71% trials) and cytomegalovirus infection (62% trials), respectively. Outcome metric and methods of aggregation included mean, median, proportion, proportional change and number of patients with at least one episode. Across all trials, measures were assessed at 55 different time points with a range of 1 to 11 time points per trial.Conclusions: Infection outcomes in kidney transplant recipients were frequently reported by site and organism but varied widely in terms of outcome, metrics, method of aggregation and time point of measurement. Establishment of core outcomes for infection based on the shared priorities of patients/caregivers and health professionals may improve the consistency, comparability and usefulness of trial evidence.

Background: Splenectomy vaccination is commonly employed prior to ABO-incompatible (ABOi) transplantation in case of the need for splenectomy. Concern exists that these predominantly polysaccharide vaccines may induce increased anti-A/B titres, through cross-reactivity, given that A/B antigens are also polysaccharides. Aim: To investigate the effect of pre-transplant splenectomy vaccinations on anti-A/B antibody titres in prospective ABOi renal transplant recipients. Methods: All patients who underwent ABOi transplantation at our centre with anti-A/B titres either side of vaccination were included. Vaccine type and timing of administration was collected from medical records. Paired pre-and post-vaccination anti-A/B antibody titres were compared using the Wilcoxon signed-rank test. Anti-HLA antibody data was also collected.Results: Forty-four ABOi renal transplant recipients were included. Mean recipient age at transplant was 50±11.9 years and 34% were female. The most common ABOi donor to recipient combination was A1 to O. The most frequently administered vaccines were the Quadrivalent (ACWY) meningococcal conjugate and Haemophilus influenzae type B conjugate. The median anti-A/B titre was 1:32 before (range 1:1 to 1:256) and 1:32 after vaccination (range 0 to 1:1024). For the group, there was no difference between paired pre-and post-vaccination titres (median change 0, range -3 to 5, p=0.6). The table displays titre changes by vaccine combination. Additionally there was no significant increase in anti-HLA Abs following vaccination. Conclusion: Splenectomy vaccinations had no significant impact on anti-A/B titres prior to ABOi transplantation in this cohort. These results provide reassurance regarding the safety of splenectomy vaccination pre-transplant in terms of ABOi and HLA sensitisation. Advances in drug quantification and interest in remote sampling led us to explore novel approaches to immunosuppressant monitoring. Trajan hemaPEN® is an Australian product for sampling of 4 x 2.75 μL from a drop of blood. The sample dries in the device, can be stored at ambient temperature and analysed at a later time. With a validated assay combining liquid chromatography with tandem mass spectrometry, we were able to measure tacrolimus concentrations in microsamples. Aims: To correlate tacrolimus concentrations in fingerprick samples from renal transplant recipients with routine hospital pathology results. Methods: Eighteen renal transplant recipients underwent routine venepuncture as well as fingerprick sampling to determine tacrolimus trough concentrations. Tacrolimus was extracted from hemaPEN® with concentrations measured in the pharmacology laboratory. The hospital pathology service undertook routine quantification in 200 μL of venous blood with Abbott Architect® immunoassay. Results: Tacrolimus extraction from two hemaPEN® sample pads (5.5 μL) gave reliable results for concentrations ≥ 5 μg/L (see figure) . Extraction from a single pad (2.75 μL), however, was insufficient for reliable quantification due to incomplete drug recovery and assay limitations. Conclusions: Dried samples of 5.5 μL capillary blood in hemaPEN® were sufficient to determine tacrolimus concentrations ≥ 5 μg/L and allow for additional analyses on the remaining sample pads. Improvements in drug extraction and assay sensitivity as well as validation in a larger patient cohort are planned. Consequently, microsamples of dried blood may allow remote self-sampling of transplant recipients.

Rowlandson M 1 , Trevillian P 1 , Mallesara G 2 , Formby M 3 , Hardstaff R 1 1 Renal and Transplantation Unit, John Hunter Hospital, Newcastle, 2 Department of Medical Oncology, Calvary Mater Hospital, 3 Department of Pathology, John Hunter Hospital, Newcastle Introduction: HNSCC is a common post-transplant malignancy amongst Australians and carries a poor prognosis. Trials of checkpoint immunotherapy have shown improved survival in patients with recurrent HNSCC compared to platinum-based therapies. Its use in organ transplant recipients, dependent on maintenance immunosuppression, is likely to be problematic but there are few reports. We describe a case of "hyperacute rejection" in a stable living donor renal transplant recipient after PD-1 inhibition with Nivolumab. Case Report: A 64 year old male received a living unrelated kidney transplant 9 years ago for ADPKD (6/6 HLA mismatch, no DSAb's,ABOi (anti-B,1:32). TCMR (Banff 1b) at 3 months treated with pulse Methylprednisolone/Thymoglobulin with biopsy proven resolution. Subsequently the eGFR maintained at ~80 ml/min for the next nine years. In 2016 he developed right tonsil SCC treated with apparently curative chemo-radiation. Mycophenolate was ceased. In 2019 his SCC reoccurred with unresectable invasive disease which required tracheostomy. He failed chemotherapy and, with consent, was given Nivolumab. Two weeks after second dose he presented with a swollen tender graft and anuria. Imaging suggested thrombosed graft. He required urgent graft nephrectomy. Histology showed diffuse interstitial haemorrhage with focal infarction and diffuse, heavy, subintimal T-cell infiltration in arteries of all sizes and peri-venously. Thromboses were not seen, C4d was negative and there were no DSAb's. The patient returned to dialysis. Conclusion: This case demonstrates aggressive T-cell mediated vascular rejection that may follow the use of checkpoint blockade. It gives insight into the likely important role of expression of PDL1 in allograft immuno-tolerance. The Westmead Institude for Medical Research, Aims: We report the first case of normothermic machine perfusion (NMP) for kidney from donation after circulatory death (DCD) in Australia. Methods: After experience using a non-clinical NMP device and successfully perfusing 15 discarded human kidneys, a TGA approved device, the Kidney Assist (Organ Assist Products, Groningen, Netherlands) was used for 4 further perfusions of discarded human kidneys. Following ethics approval and patient consent the Kidney Assist was used in November-2020 on a DCD kidney. The 52-years-old male donor who died from trauma had a total duration of cardiorespiratory withdrawal to cold perfusion of 11 minutes. The right DCD kidney had single vessels and ureter. After 219 minutes of cold storage, the graft was placed in NMP for 65 minutes at 36˚C and was pumped with combination of oxygenated packed red blood cells, prime solution, infusions of glucose/ nutrients and a vasodilator at a pressure of 75mmHg. After further 16 minutes of second cold ischaemic time (IT), the donor graft was successfully implanted in the recipient via standard technique. Results: During NMP, the renal perfusion improved with blood flow increasing from approximately 100 to 240ml/min by the end of NMP and had comprehensive global pink appearance and a urine output of 46mls (Figure 1) . A 64-years-old male with chronic glomerulonephritis received the graft with second warm IT of 27 minutes. After transplantation, the recipient experienced immediate graft function. Serum creatinine fell from a peak of 780umol/L to 164umol/L on day 17 post-transplant, with an average urine output of 1.4L/day. Immediate post-operative ultrasonographic findings showed excellent perfusion (renal index: 0.72) and peak renal artery/vein anastomotic velocity of 93cm/s and 30cm/s respectively (iliac artery velocity: 70cm/s). There were no short term vascular, urological or wound complications. Pre-implant biopsy showed acute tubular necrosis with mild tubular atrophy, fibrosis, and chronic inflammation. C4D and BK virus stains were both negative. Conclusions: Our initial experience demonstrates that NMP for DCD kidneys is feasible in the Australasian setting. This first case has shown promising outcomes. Our ongoing pilot trial will provide a preliminary assessment of benefits and evidence that a larger and definitive trial can be undertaken. PROSPECTIVE EVALUATION OF A CLOSED  INCISION NEGATIVE PRESSURE WOUND THERAPY  SYSTEM ON SURGICAL SITE INFECTIONS AND  WOUND COMPLICATIONS IN KIDNEY TRANSPLANT  RECIPIENTS. Huynh A 1 , Lam S 1 , Sandroussi C 1 , Pleass H 1,2 , Ying T 3 , Chadban S 3 , Gracey D 3 , Laurence J 1,2 1 Transplantation Services, Royal Prince Alfred Hospital, Sydney, 2 Westmead Hospital, Sydney 3 Department of Renal Medicine, Royal Prince Alfred Hospital, Sydney Aim: Closed incision negative pressure wound therapy systems are effective in reducing wound complications in numerous surgical specialties. Data however, is lacking for kidney transplantation, a specialty constantly contending with wound complications due to inherent patient factors inclusive of obesity, diabetes mellitus, and immunosuppressive drug therapy. The aim of this study was to determine the effectiveness of closed incision negative pressure wound therapy (ciNPWT) in preventing wound complications in kidney transplant recipients. Methods: A prospective cohort of overweight (BMI ≥25kg/m2) adult kidney transplant recipients utilised a closed incision negative pressure wound therapy, 'Prevena', and were compared with those who used conventional dressings ('Comfeel Plus ®') over an iliac fossa incision. The primary outcome assessed was wound complications and surgical site infections in both conventional and Prevena dressings. Results: There were 80 eligible subjects (54 conventional vs. 26 Prevena), and 26 unmatched pairs after propensity score matching. Wound complications were similar in the unmatched cohort for the convention dressing and Prevena groups (27.8% vs. 23.1% respectively, p=0.654), and matched cohort (34.6% vs. 23.1% respectively, p=0.358). Surgical site infections rates were similar for both groups in the unmatched cohort (7.4% vs. 11.5% respectively, p=0.676) and matched cohort (7.7% vs. 11.5% respectively, pandgt;0.999). Conclusion: There is no significant differences in wound complications and surgical site infections in kidney transplant recipients with the use of ciNPWT compared to conventional dressings. This data can be used to inform power calculations for future randomised controlled trials.

Ravichandran K 1 , Hewa-Geeganage S 2 , Tan A 2 , Lockwood D 2 , Ray M 2 , Kanagarajah V 2 , Lawson M 2 , Preston J 2 , Griffin A 2 , Rhee H 2 1 Department of Surgery, Princess Alexandra Hospital, Brisbane, 2 Transplant Surgery, Princess Alexandra Hospital, Brisbane Aims: Occasionally during cadaveric retrieval surgery, small renal lesions are identified that have the appearance of a malignant lesion. Following multidisciplinary assessment and consent of patients to the risks of cancer recurrence and surgical complications, tumourectomised kidneys are transplanted. This study analyses the outcomes of patients who received tumourectomised kidneys from cadaveric donors with incidental small renal lesions. Methods: Retrospective review was performed of transplant recipients of a cadaveric tumourectomised kidney at the Princess Alexandra Hospital between May 1996-May 2020. Demographics, rate of recurrence, tumour characteristics, graft survival, surgical and immunological complications as well as creatinine at 1 and 5 years was completed by chart review. Results: Of 63 patients whom received tumourectomised kidneys, 10 received a cadaveric graft. All patients had histopathologically confirmed renal cell carcinoma (RCC). Mean age of recipients was 65.6 (+/-8.9) years. Overall and graft survival for recipients at 1, 5 and 10 years was 100%, 80% and 66.6% respectively. Average creatinine for patients at 1 and 5 years was 184 (+/-43) umols/L and 197 (+/-39) umols/L. Recurrence free survival rate was 100% after 5 years of follow up. One local relapse occurred at 5.5 years post transplantation; surveillance demonstrating no further progression. Urine leak occurred in 3 patients, which settled with drainage. Delayed graft function, acute and delayed rejection occurred in 2, 2 and 1 patients respectively. Conclusion: The study demonstrates acceptable oncological and renal function outcomes from using cadaveric tumourectomised kidneys from selected donors with small RCC. However stringent protocol of follow up imaging to determine recurrence should be utilised.