Association of distinct clinical subsets with myositis‐specific autoantibodies towards anti‐155/140‐kDa polypeptides, anti‐140‐kDa polypeptides, and anti‐aminoacyl tRNA synthetases in Japanese patients with dermatomyositis: a single‐centre, cross‐sectional study

Abstract

Objective: To determine the association of distinct clinical subsets with myositis‐specific autoantibodies (MSAs) towards anti‐155/140‐kDa polypeptides [anti‐155/140 antibodies (Abs)], anti‐140‐kDa polypeptides (anti‐140 Abs), and anti‐aminoacyl tRNA synthetases (ARS Abs) in Japanese patients with dermatomyositis (DM).

Methods: We compared the clinical features and short‐term prognoses of 30 DM patients whose serological status included these MSAs. The MSAs were determined by immunoprecipitation.

Results: Anti‐155/140 Abs (n = 5), anti‐140 Abs (n = 8), and anti‐ARS Abs (n = 7) did not overlap each other. All of the anti‐155/140 Ab‐positive patients (n = 5) were complicated by malignancies, as were all of the anti‐140 Ab‐positive patients (n = 8), who showed rapidly progressive interstitial lung disease (ILD). The survival rate at 6 months from the diagnosis of DM was significantly lower in the anti‐140 Ab‐positive patients than in the other patients.

Conclusion: This is the first study to report, in a single cohort of DM patients, that distinct clinical subsets are distributed in an anti‐155/140 Ab‐positive group, an anti‐140 Ab‐positive group, or an anti‐ARS Ab‐positive group. Our data also confirm previous evidence that anti‐155/140 Abs are involved in malignancies and that anti‐140 Abs are involved in rapidly progressive ILD.