Onset and Relapse of Juvenile Dermatomyositis Following Asymptomatic SARS-CoV-2 Infection

PURPOSE OF THE STUDY: To evaluate if severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection could promote the initial development or relapse of Juvenile Dermatomyositis (JDM). The secondary aim was to identify if SARS-CoV-2 played a role in triggering of JDM through induction of interferon-α (IFNα). STUDY POPULATION: This study included 10 patients with new disease onset (n = 6) or relapse (n = 4) of JDM at a single center in France between April 2020 and March 2021. All patients met diagnostic criteria for JDM according to the European Neuro Muscular Centre 2018 dermatomyositis classification criteria. METHODS: This was a cross-sectional analysis of IgG and IgM levels directed against 5 different portions of the SARS-CoV-2 virus in the plasma of 10 patients with new onset or relapse of JDM at the time of diagnosis. The point prevalence of a positive SARS-CoV-2 infection concomitantly among new onset or relapse of JDM was determined using basic data analysis. Descriptive statistical analysis was also performed comparing the level of interferon-α2 (IFNα2) protein among 2 patients with concomitant SARS-CoV-2 infection against median IFNα2 protein levels of 33 JDM patients with active disease followed in the same clinical center. RESULTS: Out of the 10 patients, this study identified 2 (20%) patients with high titers of both IgG and IgM antibodies directed against SARS-CoV-2 proteins. One patient had new onset JDM (P1) and the second patient had relapsing JDM (P2). The clinical presentation at relapse (isolated to skin) in P2 was similar to the lesions observed at diagnosis. Both had an asymptomatic SARS-CoV-2 infection. Two weeks after diagnosis, there was a 150-fold increase in the IFNα2 level in P1 (73 476 fg/mL) and a 9-fold increase in the IFNα2 level in P2 (4612 fg/mL) compared with the median IFNα2 level (491 fg/mL) in 33 patients with active JDM at same clinical center. For P2, following treatment with IVIG and corticosteroids, there was a progressive decrease in IFNα2 level (1466 fg/mL) seen at 10 weeks after symptom onset. CONCLUSIONS: The point prevalence was 20% for a concomitant SARS-CoV-2 infection among the 10 patients with new onset or relapse of JDM at a single clinical center in France. SARS-CoV-2 infection may trigger the development of JDM through induction of IFNα.