ABSTRACT
Introduction: SARS-CoV-2 is a RNA virus that associates with heterogeneous clinical manifestations and complications. Auto-antibodies are identified in approximately 50% of hospitalized COVID-19 patients. Objectives: To determine the global incidence of myositis-related auto-antibodies (non Jo1-RNA synthetases: anti-PL7, anti-PL12, anti-EJ, anti-OJ and RNA-sensor: anti-MDA5) in our laboratory during COVID-19 pandemics, and to describe the clinical and laboratory features of these patients. Study design: A retrospective study was performed from 2015 to 2021 in a cohort of 444 patients with suspected inflammatory myopathy. The incidence of positive results for the MSA was expressed as absolute value per year for the reference population. Immunoblot analysis, indirect immunofluorescence and HLA typing of 36 patients with positivity for MSAs were collected and analyzed. Results: We observed MSA positive in 28 patients in 2020 and 36 patients in 2021, representing a mean increase of 6-fold respect to previous years since 2015 (range, 0 to 19). In 2020, the most common antibody detected was anti-MDA5 (68%). In contrast, in 2021 the most common antibodies were anti-PL7 and/or anti-PL12 (69%). All patients in 2021 with positive anti-synthetases were fully vaccinated, 4 had previous documented infection, with median time from vaccine to MSA positivity of 5 months. Eight out of 36 patients (22%) reported clinical onset after SARS-CoV-2 vaccination and 6 out of 36 (17%) presented clinical and/or radiological worsening after SARS-CoV-2 vaccination. All patients presented with a known human leukocyte antigen (HLA)-DRB1* allele associated with ASS. The most prevalent alleles identified were DRB1*03:01, DRB1*04, DRB1*11:01, corresponding to 70% (16/23) of our cohort. Conclusions: Our preliminary data show an increased incidence of anti-synthetase antibodies during COVID-19 pandemic and SARS-CoV-2 vaccination associated to HLA DRB1* risk allele. Differential profiles of MSA specificities were observed: mainly against RNA-sensors in 2020 and against RNA-synthetases in 2021. Further studies are needed to support the association between SARS-CoV-2 infection and/or vaccination and the occurrence of this autoimmune syndrome.
ABSTRACT
The clinical presentation of dermatomyositis (DM) is diverse, with varied phenotypes that may be correlated with specific autoantibodies. The anti-melanoma differentiation-associated gene 5 (MDA5) antibody in DM is associated with an amyopathic phenotype of DM, with several unusual cutaneous manifestation and increased risk for rapidly progressive interstitial lung disease. Initial presentation may be subtle, but early diagnosis is key to initiation of proper immunosuppressive therapy. In this report, we describe perinasal edema and erythema as a presenting complaint of anti-MDA5 DM in an otherwise healthy 40-year-old woman. The edema began shortly after heavy sun exposure and was followed by painful papules in her hands and arthritis within a few weeks. She was found to have high titer of anti-CCP and anti-MDA5, and thus was diagnosed with DM and rheumatoid arthritis overlap. A CT chest, abdomen, and pelvis showed patchy ground-glass and interstitial opacities in bilateral lower lobes consistent with mild interstitial lung disease without evidence of malignancy. Perinasal cutaneous findings and arthralgias improved with initiation of prednisone. To our knowledge, this is the first report of perinasal edema as a presenting symptom for DM and should raise suspicion for MDA-5 disease.