key: cord-283141-dh8j7lyl authors: Haskologlu, Sule; Kostel Bal, Sevgi; Islamoglu, Candan; Aytekin, Caner; Guner, Sukru; Sevinc, Selin; Keles, Sevgi; Kendirli, Tanil; Ceylaner, Serdar; Dogu, Figen; Ikinciogullari, Aydan title: Clinical, immunological features and follow up of 20 patients with dedicator of cytokinesis 8 (DOCK8) deficiency date: 2020-03-11 journal: Pediatr Allergy Immunol DOI: 10.1111/pai.13236 sha: doc_id: 283141 cord_uid: dh8j7lyl Biallelic mutations in the dedicator of cytokinesis 8 gene (DOCK8) cause a progressive combined immunodeficiency (CID) characterized by susceptibility to severe viral skin infections, atopic diseases, recurrent respiratory infections, and malignancy. Hematopoietic stem cell transplantation (HSCT) is only curative treatment for the disease. However, there is limited information about long‐term outcome of HSCT and its effect to protect against cancer development in DOCK8‐deficient patients. In this study, we retrospectively evaluated clinical and immunologic characteristics of 20 DOCK8‐deficient patients and outcome of 11 patients who underwent HSCT. We aimed to report the experience of our center and the result of the largest transplantation series of DOCK8 deficiency in our country. Median follow‐up time is 71 months (min‐max: 16‐172) in all patients and 48 months (min‐max: 5‐84) in transplanted patients. Atopic dermatitis (18/20), recurrent respiratory tract infections (17/20), and food allergy (14/20) were the most frequent clinical manifestations. Failure to thrive (13/20), liver problems (12/20), bronchiectasis (11/20), chronic diarrhea (10/21), and autism spectrum disorders (3/20) were remarkable findings in our series. Elevated IgE level (20/20) and eosinophilia (17/20), low IgM level (15/20), and decreased CD3+ T (10/20) and CD4+ T (11/20) cell count were prominent laboratory findings. HSCT was performed in 11 patients. All patients achieved adequate engraftment and showed improvement in their clinical and immunologic findings. Atopic dermatitis and food allergies improved in all patients, and their dietary restriction was stopped except one patient who was transplanted recently. The frequency of infections was decreased. The overall survival is 91% in HSCT‐received patients and 80% in all. HSCT at the earliest possible period with most suitable donor‐ and patient‐specific appropriate conditioning regimen and GvHD prophylaxis is lifesaving for DOCK8 deficiency cases. and its effect to protect against cancer development in DOCK8-deficient patients. In this study, we retrospectively evaluated clinical and immunologic characteristics of 20 DOCK8-deficient patients and outcome of 11 patients who underwent HSCT. We aimed to report the experience of our center and the result of the largest transplantation series of DOCK8 deficiency in our country. Median follow-up time is 71 months (min-max: in all patients and 48 months (min-max: in transplanted patients. Atopic dermatitis (18/20) , recurrent respiratory tract infections (17/20) , and food allergy (14/20) were the most frequent clinical manifestations. Failure to thrive (13/20) , liver problems (12/20) , bronchiectasis (11/20) , chronic diarrhea (10/21), and autism spectrum disorders (3/20) were remarkable findings in our series. Elevated IgE level (20/20) and eosinophilia (17/20) , low IgM level (15/20) , and decreased CD3+ T (10/20) and CD4+ T (11/20) cell count were prominent laboratory findings. HSCT was performed in 11 patients. All patients achieved adequate engraftment and showed improvement in their clinical and immunologic findings. Atopic dermatitis and food allergies improved in all patients, and their dietary restriction was stopped except one patient who was transplanted recently. The frequency of infections was decreased. The overall survival is 91% in HSCT-received patients and 80% in all. HSCT at the earliest possible period with most suitable donor-and DOCK8 deficiency is an autosomal recessive CID syndrome characterized by atopy (dermatitis, food allergies, and asthma), recurrent sinopulmonary and severe/persistent cutaneous viral infections, mucocutaneous candidiasis, early-onset malignancy, and elevated IgE levels and eosinophilia. 1-3 DOCK8 protein is a member of the DOCK180-related family, which is involved in the cytoskeletal rearrangements. DOCK8 is required for T lymphocyte, natural killer (NK) cell function and survival, dendritic cell migration, B-cell proliferation, immunoglobulin production, and antiviral cytokine production. [4] [5] [6] [7] Atopic dermatitis (AD), food allergy (FA), and wheezing are usually the initial symptoms of DOCK8 deficiency during the early infancy period. However, chronic or severe infections, autoimmunity, and cancer development may affect the course of the disease and survival. 8, 9 HSCT is the lifesaving therapy in DOCK8-deficient patients; it should be performed as early as possible, before the occurrence of malignancies and fatal infections. HSCT has been shown to cure nearly all clinical and laboratory manifestations of DOCK8 deficiency by reconstituting the normal function of the immune system. [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] Since the parental consanguinity rate is high (23.2%) in Turkey, DOCK8 deficiency has an important place among CIDs. Here, we retrospectively evaluated the clinical and immunologic features and treatment modalities of 20 patients with DOCK8 deficiency and follow-up results of hematopoietic stem cell transplant (HSCT) in 11 patients among them as a single-center experience. Twenty patients (11 girls and 9 boys) from 14 families diagnosed and followed up with DOCK8 deficiency from 2004 to 2018 in Ankara University School of Medicine, Department of Pediatric Immunology-Allergy of Children's Hospital, were evaluated retrospectively. DOCK8 protein expression was evaluated by flow cytometry as previously described. 23 Next-generation sequencing (NGS) and then Sanger's sequencing methods were used to detect and validate the DOCK8 mutations, respectively. The study was approved by the local ethics committee of Ankara University Faculty of Medicine and performed in accordance with the principles of the Declaration of Helsinki. The written informed consent was obtained from all the patients and/or their parents. Eleven of /20 patients (six girls and five boys) are transplanted so far. The median time from diagnosis to HSCT was 8 months (0-48 months). Myeloablative conditioning (MAC) regimen consisting of IV fludarabine 40 mg/m 2 /day and IV busulfan 4 mg/kg/day on days −5, −4, −3, and −2 was administered to two patients (P5 and P7), while all others received treosulfan-based reduced-intensity conditioning (RIC). Treosulfan was given at a dose of 42 or 36 g/m 2 (<1 year of age) in three divided doses on −7, −6, and −5 days. CsA was given alone in six patients transplanted from MRD and in combination with mycophenolate mofetil (MMF) or methotrexate (MTX) in two patients where peripheral blood-derived stem cells (PBSCs) were used. One patient received tacrolimus and MTX. Antithymocyte globulin (ATG) was added to the conditioning regimen in a MUD (9 of 10 HLA matched) and a haploidentical (in conjunction with post-transplantation cyclophosphamide (PT/Cy) for GvHD prophylaxis) donor setting. Acute and chronic GvHDs were graded according to modified Glucksberg and NIH consensus criteria, respectively. 24, 25 Immunosuppression was stopped at 6 months after HSCT if there was no evidence of cGvHD. Myeloid engraftment was defined as the absolute neutrophil count being higher than 0.5 × 10 9 /L and platelet counts exceeding 50 × 10 9 /L without transfusion for at least three consecutive days. Immune reconstitution was evaluated by measuring the levels of CD3+, CD4+, CD8+, CD19+, CD20+, CD16+ 56+, CD4+ CD45RA+, and CD45RA+ CD31 patient-specific appropriate conditioning regimen and GvHD prophylaxis is lifesaving for DOCK8 deficiency cases. clinic, DOCK8 deficiency, follow-up, hematopoietic stem cell transplantation, immunological features In our 20 patients with DOCK8 deficiency, we obtained some different findings with classical findings. In addition, we present the results of the largest transplantation series of DOCK8 deficiency in our country. (recent thymic emigrant, RTE) cells with flow cytometry (Beckman Coulter, Navios Software, Kaluza, Miami, USA). DOCK8 protein expression was analyzed with flow cytometry before and after 6 months following HSCT as described previously 23 (Figure 1 ). Myeloid and T-cell donor chimerisms were measured by using PCRbased amplification of short tandem repeat sequences in DNA of the cells following the separation of peripheral blood samples at +1st, 2nd, 3rd, 6th, 9th, 12th, and 18th months following HSCT by Automated Magnetic Cell Sorting (Miltenyi Biotec). Full donor chimerism was defined when >95% of the cells originated from the donor. All patients were nursed in an isolated room, and they all received weekly prophylactic, antimicrobial, and IVIG therapies. The clinical characteristics, genetic features, and treatment modalities of the patients are presented in Table 1 . The immunologic data are given in Figure 2 . All patients were born to consanguineous parents. The median age at diagnosis and at HSCT was 3 years In addition to previously reported data about a patient (P7), 26 All patients received Ig replacement therapy, trimethoprim-sulfamethoxazole, acyclovir, and fluconazole prophylaxis. Severe oral herpes infection of P7 was treated successfully with interferon α2b, while in P6, interferon α2b treatment was ceased due to side effects (fever and myalgia) early after its initiation. A total of three patients died: two (P2 and P3) because of intracranial NHL and one (P4) because of cholestatic liver failure before the definitive DOCK8 diagnosis. Donor screening is still being processed in six patients. Table 2 . Table 3 . Here, we report clinical and immunologic findings of 20 DOCK8deficient patients while reviewing the outcomes of 11 transplanted cases among them. Our study is the largest single-center cohort reported from Turkey. Furthermore, six novel mutations were reported in this cohort. Our patients had unique features that Turkish patients participating in previous studies did not have. 8, 9 In addition to classical clinical features, gastrointestinal problems (liver and inflammatory bowel disease) were more common, while viral skin infections were less common in our series compared with the literature. 8, 9 BCG vaccine-related complications were seen in five patients for the first time. The median age of our patients (3 years, 2 month-14 years) was lower than the previous studies, and mild clinical findings were found in patients diagnosed during infancy period. Molluscum contagiosum or herpes zoster infections were not detected in our series. HPV was detected in only one patient. Mucosal herpes simplex virus (HSV) infections were observed at similar rates with the literature (35%). Gastrointestinal problems (liver and inflammatory bowel disease) in this study were more common than in previous studies. 8, 9 These abovementioned differences might be due to patients' young age, the characteristics of the genetic mutations, and epigenetic factors influencing the genotype. There is limited information about the speech and developmental problems in DOCK8 deficiency. Three of our patients have speech problems and pervasive developmental problems. Because all these patients' parents are consanguineous and two of the patients are siblings, it suggests that other genetic etiologies may be responsible for the PDD. More than 60% of the non-transplanted patients are reported to die due to malignancy or severe infections before the age of 30 years. 8 In our series, three patients died before the detection of DOCK8 mutations due to central nervous NHL (P2 and P3) and liver failure (P4). Thus, HSCT is suggested to all patients with DOCK8 deficiency; even patients with significant comorbidities should undergo HSCT as early as possible after aggressive treatments of these conditions to minimize complications and to achieve engraftment. [8] [9] [10] [11] [12] Recently, HSCT outcomes of 81 transplanted patients with -13 In our study, cGvHD rate is higher than the previous studies. [10] [11] [12] [13] It could be related to severe organ damage and inflammatory morbidities due to delayed diagnosis and HSCT in our cohort. All patients who developed cGvHD were older than 4 years of age. Severe cGvHD was the most important complication we have seen after HSCT in DOCK8-deficient patients. Previous series report persistence of food allergies after HSCT. 10, 25 However, in our series food allergies were improved in all patients except for one patient who was transplanted recently. We did not observe allergic reactions in the patients after stopping dietary restrictions. Although the underlying cause of development of autoimmunity is not clear in DOCK8 deficiency, autoimmune diseases-even celiac disease-disappeared in our patients after transplantation. Eight of 11 patients undergoing HSCT had failure to thrive. Only two patients were able to achieve normal growth after is lifesaving for DOCK8 deficiency. cGvHD is the most important complication after HSCT. In our opinion, GvHD prophylaxis is very important and GvHD findings should be followed very closely and treated aggressively. Long-term follow-up is necessary to see how immunologic features progress and how effects on the prevention of malignancy and survival in transplanted patients will be. Despite most of the mutations found in DOCK8-deficient patients are loss-of-function mutations that abolish DOCK8 protein expression, very low but detectable levels of DOCK8 protein can be expressed in some patients. 27 The residual DOCK8 protein contributes to the variable disease phenotype. In our cohort, four patients with mild phenotype (P15, P16, P18, and P20) diagnosed in early infancy demonstrated some residual DOCK8 protein expression by flow cytometric analysis. Therefore, examination of DOCK8 protein expression by flow cytometry in early infancy in suspected patients is a rapid and reliable diagnostic approach. We suggest that all patients suspected to have DOCK8 deficiency be followed up closely, and DOCK8 expressions be measured by flow cytometry and confirmed by genetic study and performing HSCT as soon as possible. The authors declare that they have no conflicts of interest. 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The. Diagnosis and Staging Working Group report Plasmacytoid dendritic cell depletion in DOCK8 deficiency: rescue of severe herpetic infections with IFN-α 2b therapy Insights into immunity from clinical and basic science studies of DOCK8 immunodeficiency syndrome GvHD. c P13's immunosuppressive treatment was discontinued 2 mo ago, and P14 was still receiving immunosuppressive treatment.