key: cord-0923176-y0cdcdfc
authors: Naveed, Zunaira; Sarwar, Musharraf; Ali, Zahid; Saeed, Danish; Choudhry, Khadija; Sarfraz, Azza; Sarfraz, Zouina; Felix, Miguel; Cherrez‐Ojeda, Ivan
title: Anakinra treatment efficacy in reduction of inflammatory biomarkers in COVID‐19 patients: A meta‐analysis
date: 2022-04-18
journal: J Clin Lab Anal
DOI: 10.1002/jcla.24434
sha: c996cea7193036aca7abe376bd18f61d3478319c
doc_id: 923176
cord_uid: y0cdcdfc

INTRODUCTION: Anakinra is being empirically considered for the treatment of COVID‐19 patients. The aim is to assess the efficacy of anakinra treatment on inflammatory marker reduction, including c‐reactive protein (CRP) concentrations, serum ferritin, and serum d‐dimer levels. METHODS: Adhering to PRISMA 2020 statement guidelines, a systematic search was conducted across the following databases from December 2019 until January 10, 2022: PubMed/MEDLINE, Cochrane Central, Web of Science, Scopus, and EMBASE. The following keywords were employed: Anakinra, COVID*, SARS‐CoV‐2, inflammatory, CRP, D‐dimer, Ferritin, hematological, laboratory, clinical, trials. The findings were collated and presented in a tabulated manner, and statistically analyzed using Review Manger 5.4 (Cochrane). RESULTS: In total, 2032 patients were included (881 in the anakinra and 1151 in the control/standard care group); 69.1% of them were males. Overall, the mean difference from admission until last follow‐up in CRP values was −9.66, where notable reductions were seen in the anakinra group (SMD = −0.46, p < 0.00001, N = 655). Serum ferritin mean values were reduced by 1467.16 in the anakinra group (SMD = −0.31, p = 0.004, N = 537). D‐dimer mean values were largely reduced by 4.04 in the anakinra group (SMD = −0.38, p = 0.0004, N = 375). CONCLUSION: This study finds that anakinra is potentially a strong candidate as an anti‐inflammatory agent to reduce mortality in COVID‐19 patients, specifically in patients with elevated inflammatory biomarkers.

Inflammation is a key driver of the severity of COVID-19 infection among patients. 1 Preliminary reports since the initial stages of the pandemic have demonstrated that elevated concentrations of proinflammatory markers are more pronounced in severe or critically ill COVID-19 patients than milder cases. 2 Anakinra is a recombinant interleukin-1 receptor antagonist (IL-1Ra), a regulatory molecule with activity against both IL-1α and IL-1β, that emerged as a candidate to reduce hyper-inflammation and concomitant mortality in COVID-19

patients. 3 The pro-inflammatory cascade is similar to the macrophage activation syndrome (MAS), and COVID-19 hyper-inflammation may benefit from cytokine-blocking agents such as Anakinra. 4, 5 The severe hyper-inflammation in a subset of COVID-19 patients resembles MAS and is associated with hyper-ferritinemia, fever, and diffuse intravascular coagulation (DIC). 4, 6 Anakinra has been used empirically across several clinical settings in COVID-19 and has had positive effects, including mortality reduction. [7] [8] [9] As the potential effect of Anakinra is due to inhibition of the pro-inflammatory cascades, it is likely to lead to suppression of systematic inflammation, control of fever, and inhibition of host inflammatory responses to viral replication in COVID-19. 7,10 Although systematic inflammation may not be significant in all patients, there is evidence of localized hyper-inflammation in the lungs, making Anakinra an attractive candidate for moderate-to-severe COVID-19 infections as concomitant therapy. 7, [11] [12] [13] So far, Anakinra has been administered as an off-label medication for patients with clinical or laboratory signs of hyper-inflammation in COVID-19 patients to mitigate IL-1-mediated pro-inflammatory cascades. 14 The severe hyper-inflammation in these patients is characterized by laboratory markers including c-reactive protein (CRP), serum ferritin, and d-dimer levels. 15 It remains unclear whether Anakinra confers an additional advantage to COVID-19 patients to mitigate hyper-inflammation beyond the current standard of care. Reports of COVID-19 increasingly recognize two types of distinct, yet overlapping phenotypic and pathological subsets of pneumonia-these include viral pneumonitis and virus-triggered overreacting immune response. 16, 17 The later phenotype is a more severe form of disease and is typified by rapid progression to acute respiratory failure, often necessitating invasive ventilatory support.

With severe COVID-19 pneumonia on invasive ventilatory support, excessive mortality is documented. 16, 17 The excessively high rates of death are attributed to severe hyper-inflammation. 4, 8, 16 The aim of this meta-analysis is to document whether anakinra in patients with COVID-19 pneumonia is beneficial for improvement of inflammatory biomarkers (i.e., CRP, serum ferritin, and d-dimer).

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement 2020, randomized controlled trials and observational studies employing an intervention group (anakinra) compared to the control/standard of care (SoC) group were included. The studies reported inflammatory biomarkers at baseline (on admission or enrollment) and on endline (completion of study or last follow-up). These laboratory-based outcomes were reported in anakinra and control/SoC groups. The data were systematically reviewed and meta-analyzed to quantify the standardized changes of inflammatory laboratory markers (CRP, serum ferritin, and d-dimer).

Randomized clinical trials, retrospective or prospective cohorts, were considered. Case series, case reports, systematic reviews, meta-analyses, and letters were omitted due to the high risk of biases associated with the study types and lack of control groups for comparison purposes. The studies were required to include adult participants, aged 18 or above, with no restrictions to genders of All the identified studies were de-duplicated by entering bibliographic details into EndNote X9 (Clarivate Analytics). The methodology was both quantitative and analytical where the mean difference (MD) on admission/enrollment and on last follow-up was analyzed. The mean difference is a common meta-analytical measure to note the difference in means from the baseline to endline, which may be both negative and positive. These laboratory values were continuous in nature and were aligned to a single scale across CRP, serum ferritin, and d-dimer. The standardized mean difference (SMD), which is an effect measure, was computed applying 95% confidence intervals (CI). A fixed-effects model was applied for the laboratory outcomes since they were converted to a single unit of measure, as recommended by Cochrane's handbook. The additional outcome for mortality was conducted using a random-effects model, with outcomes reported as Risk Ratio (RR) using 95% CI. Forest plots were generated for all the outcomes that represented the effect size (SMD and RR), heterogeneity, and overall test results. Funnel plots accompanied the forest plots for all outcomes. At least 2 or more studies were required to report the same outcome measure to be meta-analyzed. Heterogeneity was testing using the χ²-based Q test and the I 2 index. All statistical tests were conducted using Review 

The overall Kappa score computed for the inter-reviewer agreement was 0.91, suggesting good agreement. The characteristics of included studies are enlisted in Table 1 Table 1 .

The laboratory values for d-dimer (mg/L), CRP (mg/L), and ferritin (ng/ml) are reported in Table S1 . The values were reported at baseline, that is, on admission and on the last day of follow-up or peak where applicable, were presented as mean (SD) unless stated otherwise (Table S1) . The results indicate that the risk of mortality was reduced in the anakinra group by 36% (I 2 = 48%) ( Figure 5 ).

To note any sources of bias, a funnel plot was generated and studied. While we expected for there to be large sources of heterogeneity due to the differing nature of study types included, the funnel plot shows an otherwise inverted funnel shape with only 3 studies deviating from the total of 16. It may be stated that minimal-moderate sources of bias were present in this meta-analysis ( Figure 6 ).

Our 21 The clinical utility of CRP as a prognostic test for COVID-19 severity has previously been established, and it remains broadly relevant to correlate with severity and treatment responses. 22 The IL-1 signaling pathway is a major target for immune modulation and serves as the apical pro-inflammatory mediator, especially in innate immunity. 23 Anakinra is a short-acting IL-1Ra leading to dual IL-1α and IL-1β inhibition, which is associated with lower CRP concentration. 24 ILβ is the primary form of circulating IL-1, whereas IL-1α remains largely membrane-bound. 25 IL-1α

and IL-1β bind to the universally expressed cell surface receptor, IL-1R, to activate the cascade of IL-1-mediated inflammatory responses downstream. 23 Anakinra antagonizes the IL-1R to control the activity of the NLRP3 inflammasome through caspase-1-mediated activation of IL-1β and production of a variety of innate inflammatory responses downstream, including IL-6, which is closely linked to the severity of COVID-19 infection. 26, 27 Overall, anakinra is mechanistically and clinically emerging as a strong candidate to target the pro-inflammatory syndrome observed in COVID-19 patients with a significant reduction in CRP levels reported in our findings as well as other studies. 28 Anakinra has previously shown efficacy in patients with sepsis and features of MAS. 29 MAS is associated with an excessive inflammatory response, specifically high ferritin concentrations. 30 The of ferritin-activating macrophages and increased iron metabolism required for controlling viral infections is a potential mechanism for increased pro-inflammatory cytokines in COVID-19. 35 Also, ferritin may be related to inflammatory parameters and suggestive of cellular damage when its value is over 600 ng/ml. 36 The high ferritin levels observed in COVID-19 patients also result in ferroptosis, one of the underlying mechanisms in acute respiratory distress syndrome (ARDS), similar to COVID-19 pneumonia. 37 Iron parameters including ferritin have also been correlated with improvement in the sequential organ failure assessment (SOFA) score, which provides further rationale for the utility of Anakinra in COVID-19 patients. 38 While the role of ferritin as an inflammatory biomarker in COVID-19 remains unclear, Anakinra has a potential role in the hyper-ferritinemia associated with COVID-19 progression and severity. 39 We demonstrate the reduction in serum ferritin levels with anakinra use which is encouraging.

D-dimer is a fibrin degradation product and a well-recognized biomarker for thrombotic disorders. 40 Its utility as a prognostic marker has already been established in community-acquired pneumonia and more recently in COVID-19 patients. 41, 42 While there is variation in the cutoff for morbidity and mortality prediction, a value less than 0.5 ug/ml is widely considered normal. 43 To the best of our knowledge, this is the first patient-level metaanalysis that evaluates the effect of anakinra treatment in COVID-19

patients and relevant hyper-inflammatory biomarkers to advance the current understanding of this treatment. Our findings suggest a positive impact on the hyper-inflammatory biomarkers noted in COVID-19 patients. However, anakinra is an immunosuppressive drug that may theoretically cause more harm than benefit when targeting "beneficial" inflammation. 28 Anakinra is noted to have positive effects on hyper-inflammation, which needs to be evaluated further. The current criteria for anakinra administration in clinical trials consider CRP, serum ferritin, and d-dimer levels; there is no consensus on the standard cutoff in COVID-19 patients. Another important consideration is the dose and route of administration of anakinra due to its short half-life. This study's main limitation is the observational design of many studies included in the meta-analysis.

These studies may be biased and have possible confounders such as concomitant use or lack of dexamethasone as the standard of care. Anakinra, regardless, remains a strong potential candidate, as demonstrated by our findings, and it is recommended to conduct randomized clinical trials with caution. These trials may focus on homogenous eligibility criteria and dosing regimens to provide meaningful insight into the efficacy of anakinra in COVID-19 patients with hyper-inflammation. armamentarium.

The authors declare no conflicts of interest.

All data obtained for the purpose of this meta-analysis are freely available online.

https://orcid.org/0000-0001-8206-5745

Zouina Sarfraz https://orcid.org/0000-0002-5132-7455

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