Long-term outcomes and chronological remaining normal lung volumes in patients with interstitial lung disease with anti-aminoacyl tRNA synthetase antibodies and anti-melanoma differentiation-associated gene 5 antibodies

Abstract

Objective: To evaluate long-term outcomes and multi-slice computed tomography（MSCT）-measured chronological remaining normal lung volume in patients with interstitial lung disease（ILD）having the anti-aminoacyl tRNA synthetase（ARS）or the anti-melanoma differentiation-associated gene 5（MDA5）antibodies.

Methods: We retrospectively investigated 51 ILD patients with anti-ARS（n = 38）or anti-MDA5（n = 13）between January 2014 and May 2019. Patients were classified as having polymyositis/dermatomyositis（PM/DM）, clinically amyopathic DM（CADM）, or interstitial pneumonia with autoimmune features. The MSCT-based chronological remaining lung volumes were measured.

Results: A total of 29%, 45%, and 5%, and 0%, 31%, and 54% of patients with anti-ARS and anti-MDA5 had PM/DM/CADM, respectively. The MSCT-measured mean（SD）remaining lung volumes at baseline were 3100（720）mL and 2796（887）mL in the anti-ARS and anti-MDA5 groups, respectively（P = 0.226）. Survival was more favorable in patients with anti-ARS than in those with anti-MDA5（93% vs. 77% at 4-year, P = 0.022）. Remission was achieved in 94% and 85% of patients with anti-ARS and anti-MDA5, respectively, who received induction therapy. The remaining lung volumes did not significantly increase over time [mean（SD）, 21（9）months] in the anti-ARS group（P = 0.867）but improved in the anti-MDA5 group（P = 0.030）. The mean（SD）annual percent change was 104（18）% vs. 119（15）% in anti-ARS-positive vs. anti-MDA5-positive patients（P = 0.055）.

Conclusion: Despite the favorable survival of anti-ARS-positive patients, ILD improvement was minimal. Long-term therapeutic strategies for ILD in this subset of patients are warranted.