Immune-mediated necrotizing myopathy (NAM) related to SARS-Cov-2 infection: a case report.

BACKGROUND: There is a growing body of evidence that severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or COVID-19 infection is associated with the development of autoimmune diseases. A recent systematic review reported that the new-onset autoimmune disorders during or after COVID-19 infection included inflammatory myopathies such as immune-mediated necrotizing myopathies. CASE PRESENTATION: We described a 60-year-old man diagnosed with COVID-19 infection and later presented with a two-week history of myalgia, progressive limb weakness, and dysphagia. He had a Creatinine Kinase (CK) level of more than 10,000 U/L, was strongly positive for anti-signal recognition particle (SRP) and anti-Ro52 antibody, and a muscle biopsy revealed a paucity-inflammation necrotizing myopathy with randomly distributed necrotic fibers, which was consistent with necrotizing autoimmune myositis (NAM). He responded well clinically and biochemically to intravenous immunoglobulin, steroids and immunosuppressant and he was able to resume to his baseline. CONCLUSION: SARS-CoV-2 may be associated with late-onset necrotizing myositis, mimicking autoimmune inflammatory myositis.

Genetic Biomarkers as Predictors of Response to Tocilizumab in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis.

Rheumatoid arthritis (RA) is a lifelong, debilitating disease which incredibly impacts a patient's quality of life if not treated to the optimal target. The clinical response of tocilizumab, an interleukin-6 (IL-6) inhibitor, is associated with several gene polymorphisms, particularly targeting the IL-6 pathway. This systematic review and meta-analysis seeks to investigate genetic biomarkers that predict the treatment outcome of tocilizumab therapy in RA patients. After evaluating the quality of retrieved records, five studies were chosen to carry out a quantitative synthesis involving 591 participants. We analysed genetic markers of IL-6R single nucleotide polymorphism (SNP)s rs12083537, rs2228145 and rs4329505, FCGR3A, CD69, GALNT18 and FCGR2A. A plausible finding based on meta-analysis revealed that RA patients with homozygous AA genotype for rs12083537 polymorphism of the IL-6R gene demonstrate a better response to TCZ treatment as opposed to homozygous and heterozygous patients with the G allele. Nonetheless, limitations in evaluating the available studies by meta-analysis include a lack of studies with dissimilarities in study design and outcome definitions, small sample sizes with low statistical power and heterogeneity of cohorts, a restricted the number of tested SNPs and small effects for the selected variants. Inconsistent finding remains as a great challenge to forge ahead towards personalised medicine for RA management.

Anti-MDA5 dermatomyositis after COVID-19 vaccination: a case-based review.

Anti-MDA5 (Melanoma differentiation-associated protein 5) myositis is a rare subtype of dermatomyositis (DM) characterized by distinct ulcerative, erythematous cutaneous lesions and a high risk of rapidly progressive interstitial lung disease (RP-ILD). It has been shown that SARS-CoV-2 (COVID-19) replicates rapidly in lung and skin epithelial cells, which is sensed by the cytosolic RNA-sensor MDA5. MDA5 then triggers type 1 interferon (IFN) production, and thus downstream inflammatory mediators (EMBO J 40(15):e107826, 2021); (J Virol, 2021, https://doi.org/10.1128/JVI.00862-21 ); (Cell Rep 34(2):108628, 2021); (Sci Rep 11(1):13638, 2021); (Trends Microbiol 27(1):75-85, 2019). It has also been shown that MDA5 is triggered by the mRNA COVID-19 vaccine with resultant activated dendritic cells (Nat Rev Immunol 21(4):195-197, 2021). Our literature review identified one reported case of MDA5-DM from the COVID-19 vaccine (Chest J, 2021, https://doi.org/10.1016/j.chest.2021.07.646 ). We present six additional cases of MDA5-DM that developed shortly after the administration of different kinds of COVID-19 vaccines. A review of other similar cases of myositis developing from the COVID-19 vaccine was also done. We aim to explore and discuss the evidence around recent speculations of a possible relation of MDA5-DM to COVID-19 infection and vaccine. The importance of vaccination during a worldwide pandemic should be maintained and our findings are not intended to discourage individuals from receiving the COVID-19 vaccine.