Elevated serum B‐cell activating factor levels in patients with dermatomyositis: Association with interstitial lung disease

Abstract

Patients with dermatomyositis (DM) frequently have myositis‐specific autoantibodies (MSA), which are closely associated with different clinical features. Patients with anti‐aminoacyl‐tRNA synthetase antibody (ARS‐Ab) and anti‐melanoma differentiation‐associated gene 5 (MDA5)‐Ab often have interstitial lung disease (ILD). Recently, anti‐MDA5‐Ab levels have been shown to correlate with disease activity in DM patients. Thus, B cells that are stimulated by excess B‐cell activating factor (BAFF) play an important role in the pathogenesis of DM through auto‐Ab production. In this study, we investigated the role of BAFF in DM patients. We measured the serum BAFF levels in 56 adult DM patients (14 with anti‐ARS‐Ab, 18 with anti‐MDA5‐Ab, seven with anti‐Mi‐2‐Ab and 17 with anti‐transcriptional intermediary factor‐1γ‐Ab) . For a longitudinal study, 130 serum specimens from 10 DM patients with anti‐MDA5‐Ab were analyzed. Serum BAFF levels were significantly higher in DM patients than in healthy controls. DM patients with elevated serum BAFF levels more frequently had ILD. In subgroup analysis, DM patients with anti‐ARS‐Ab and DM patients with anti‐MDA5‐Ab exhibited increased BAFF levels compared with controls, while DM patients with other MSA showed BAFF levels comparable with controls. In the longitudinal study, serum BAFF levels in DM patients with anti‐MDA5‐Ab were decreased after immunosuppressive therapy along with serum levels of anti‐MDA5‐Ab and ferritin, which are biomarkers of disease activity. These results suggest that BAFF plays an important role in the pathogenesis of ILD in DM patients with anti‐ARS and anti‐MDA5‐Ab. Furthermore, serum BAFF level is associated with disease activity in DM patients with anti‐MDA5‐Ab.

One year in review 2020: idiopathic inflammatory myopathies

“…Interestingly, BAAF levels of DM patients with other MSAs (anti-Mi2, anti-TIF1γ) did not significantly differ from HC. These findings suggested a possible role for BAAF in the pathogenesis of ILD and possibly as a potential target for treatment (70).…”

Fulminant Course of Neuromyelitis Optica in a Patient With Anti-MDA5 Antibody-Positive Dermatomyositis: A Case Report

“…In terms of ILD in our case, what caused the unexpected worsening of ILD after rituximab injection is unclear, with the rarity of similar cases. It is assumed that the post-rituximab elevation of serum BAFF level may be responsible for the exacerbation of ILD, as in post-rituximab NMO relapse, given that BAFF was recently suggested to play a major role in the development of ILD in patients with anti-MDA5-positive DM (7,23).…”

Pathogenesis of Anti-melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis: A Concise Review With an Emphasis on Type I Interferon System

“…Matsushita et al revealed that MDA5 + DM patients exhibited increased levels of BAFF when compared with healthy controls. Furthermore, serum BAFF levels in MDA5 + DM patients were reduced following immunosuppressive therapy along with the levels of anti-MDA5 antibody and ferritin ( 70 ). In addition, Zhang et al found that IFNα was correlated to BAFF in patients with MDA5 + DM and that increased levels of BAFF were associated with higher concentrations of Krebs von den Lungen-6 (KL-6) ( 71 ), a potential biomarker that reflects the severity of connective tissue disease-associated ILD ( 72 ).…”