Anti-melanoma differentiation-associated gene 5 antibody-positive interstitial lung disease masquerading as rheumatoid arthritis-associated interstitial lung disease or overlapping with the same: a phenomenon driven by a probable genetic predisposition.

Rheumatoid arthritis (RA) is a systemic, progressive illness marked by persistent synovitis that causes substantial functional disability. Treatment delays frequently affect health-related quality of life. Extra-articular features are prevalent findings in RA, which leads to significant morbidity and mortality. They are likely due to chronic inflammation and autoimmune nature of RA. Extra-articular manifestations also include interstitial lung disease (ILD). Anti-MDA5 antibodies, though typically associated with dermatomyositis, may also occur with RA, especially in patients with overlapping syndromes, and influence ILD severity. In this case-based review, we highlight the challenges in managing a case of seropositive RA complicated by the coexistence of anti-MDA5 antibody. This review additionally examines the pathophysiology, clinical presentation, diagnosis, therapy, and prognosis of RA-ILD along with that of anti-MDA-5ILD, as well as new studies and recommendations for disease management.