Myositis is a heterogeneous group of autoimmune diseases, with different pathogenic mechanisms contributing to the different subsets of disease. The aim of this study was to test whether the autoantibody profile in patients with myositis is associated with a type I interferon (IFN) signature, as in patients with systemic lupus erythematous (SLE). Patients with myositis were prospectively enrolled in the study and compared to healthy controls and to patients with SLE. Autoantibody status was analysed using an immunoassay system and immunoprecipitation. Type I IFN activity in whole blood was determined using direct gene expression analysis. Serum IFN-inducing activity was tested using peripheral blood cells from healthy donors. Blocking experiments were performed by neutralizing anti-IFNAR or anti-IFN-α antibodies. Patients were categorized into IFN high and IFN low based on an IFN score. Patients with autoantibodies against RNA-binding proteins had a higher IFN score compared to patients without these antibodies, and the IFN score was related to autoantibody multispecificity. Patients with dermatomyositis (DM) and inclusion body myositis (IBM) had a higher IFN score compared to the other subgroups. Serum type I IFN bioactivity was blocked by neutralizing anti-IFNAR or anti-IFN-α antibodies. To conclude, a high IFN score was not only associated with DM, as previously reported, and IBM, but also with autoantibody monospecificity against several RNA-binding proteins and with autoantibody multispecificity. These studies identify IFN-α in sera as a trigger for activation of the type I IFN pathway in peripheral blood and support IFN-α as a possible target for therapy in these patients.

BACKGROUND AND AIMS:People with primary biliary cholangitis (PBC) experience high rates of mental distress and fatigue despite standard of care therapy. We aimed to assess the impact of an online mind-body intervention on these symptoms. METHODS:This 12-week RCT used sequential mixed-methods evaluation. Alongside standard of care, participants with primary biliary cholangitis were randomized to receive weekly countdown emails, or the intervention consisting of (i) a weekly 20-30 minute-mind-body follow-along video, (ii) weekly 5-10-minute psychology-based "managing chronic disease skills videos," and (iii) 10-minute telephone check-ins. The primary outcome was a change in the Hospital Anxiety and Depression Scale (HADS). Secondary outcomes evaluated changes in fatigue, perceived stress, resilience, and health-related quality of life. ANCOVA determined between-group differences. RESULTS:Of the 87 randomized patients (control group: n = 44, intervention group: n = 43), the between-group HADS total score improved by 20.0% (95% CI 4.7, 35.2, p = 0.011). Significant improvements were seen in depression (25.8%), perceived stress (15.2%), and 2 primary biliary cholangitis-40 domains [emotional symptoms (16.3%) and social symptoms (11.8%)] with a mean satisfaction of 82/100. This corresponded with end-of-study qualitative findings. Although no improvements were observed in fatigue in the main analysis, a significant benefit was observed in the subgroup of intervention participants (20/36;56%) who completed the mind-body video routine at least 3 times per week. CONCLUSION:This intervention improved measures of mental wellness and quality of life with high satisfaction and reasonable adherence. Future studies could explore strategies to optimize adherence and target fatigue.

OBJECTIVE:In 2012, a large number of myositis cases with anti-mitochondrial M2 (AMA-M2) antibody, which had well been known as the serological hallmark for primary biliary cholangitis (PBC), were reported in Japan. Recently, some case series from Japan, France, America, China and India have shown that approximately 2.5% to 19.5% of patients with myositis have AMA-M2 antibody. The objective of this study was to clarify the prevalence, clinical features, treatment outcome, and severity determinants of AMA-M2 positive myositis. METHODS:This study was a multicenter observational study. We enrolled patients who were diagnosed with myositis during a ten-year period between 2012 and 2021. RESULTS:Of the total of 185 patients with inflammatory myopathy, 17 patients were positive for AMA-M2 antibody. The typical symptoms were weakness mainly involving paravertebral muscles, weight loss, respiratory failure, and cardiac complications. Thirteen of the 17 patients had cardiac complications. A strong correlation was found between respiratory failure and modified Rankin Scale (mRS) score. A strong correlation was also found between respiratory failure and body weight, indicating that weight loss can be an indicator of potential progression of respiratory failure. Six of the 17 patients were complicated by malignancy. CONCLUSIONS:This study showed significant correlations between % vital capacity (VC), body mass index (BMI), and mRS score in patients with AMA-M2-positive myositis. Immunotherapy often improved CK level and respiratory dysfunction. We therefore propose that %VC and BMI should be monitored as disease indicators in treatment of AMA-M2-positive myositis.