Characterization of Patients With Dermatomyositis According to Anti-Melanoma Differentiation-Associated Gene-5 Autoantibodies in Centers from 3 Latin American Countries: A Cohort Study.

BACKGROUND/OBJECTIVE: The anti-melanoma differentiation-associated protein 5 (MDA5) autoantibodies have been associated with a high frequency of interstitial lung disease (ILD) and rapidly progressive ILD (RP-ILD) in dermatomyositis (DM) patients, mainly in Asian subjects. However, there is scarce information about these parameters in Latin American patients. METHOD: This was a medical records review cohort study that included classic DM (CDM) and clinically amyopathic DM (CADM) patients from 3 Latin American countries (Argentina, Brazil, and Mexico). RESULTS: A total of 270 DM patients were evaluated: 25.9% with CADM and 74.1% with CDM. The overall prevalence of ILD and RP-ILD, respectively, was 70 (25.9%) and 4 (1.5%) of the 270 patients, and the distributions were comparable between patients with CDM and CADM. The anti-MDA5 was present in 31 (25.4%) of 122 CDM patients and in 17 (48.6%) of 35 CADM patients; it was not associated with presence of ILD and RP-ILD. However, anti-MDA5-positive CDM patients had significantly high frequency of "mechanic's hands," arthralgia, arthritis, and lower serum levels of creatine phosphokinase, whereas anti-MDA5-positive CADM patients had significantly high frequency of arthritis. Pulmonary infection and ILD are main causes of death in DM patients. CONCLUSIONS: In the present study, the prevalence of ILD in DM patients is comparable to that described in the literature, in contrast to the very low frequency of RP-ILD. In addition, the anti-MDA5 is not associated with ILD and RP-ILD, but anti-MDA5-positive DM patients present conditions that mimic antisynthetase syndrome. Pulmonary infection and ILD were the main causes of death in our sample.

Mycophenolate mofetil in patients with refractory systemic autoimmune myopathies: case series.

BACKGROUND: Currently, there are only few studies (mostly case reports or case series) on mycophenolate mofetil (MMF) in patients with systemic autoimmune myopathies (SAM). Therefore, the goal of the present study was to evaluate the safety and efficacy of MMF (monotherapy or coadjuvant drug) in a specific sample of patients with refractory SAM: dermatomyositis, polymyositis, anti-synthetase syndrome or clinically amyopathic dermatomyositis. METHODS: A case series including 20 consecutive adult patients with refractory SAM from 2010 to 2016 was conducted. After the introduction of MMF, associated or not with other drugs, the patients were followed for 6 consecutive months. RESULTS: In 17 out of 20 patients MMF was introduced without any intolerance. The clinical symptoms evaluated in these patients were muscular, cutaneous and/or pulmonary activity. During the 6-month follow-up, 11 out of 17 patients had clinical and laboratory activities response with MMF, allowing significant tapering of the prednisone median dose (15 vs. 5 mg/day, P=0.005). On the other hand, in three out of 20 patients; MMF was discontinued in less than two months, because of gastrointestinal intolerance. There were no cases of serious infection or death. CONCLUSIONS: MMF was relatively well-tolerated, safe and effective in patients with refractory SAM. Further studies are needed to confirm the data found.