Rituximab in Connective Tissue Disease-Associated Interstitial Lung Disease: From Immunopathogenesis to Therapeutic Implications

Connective tissue disease-associated interstitial lung disease (CTD-ILD) comprises a heterogeneous group of immune-mediated pulmonary disorders with significant morbidity and mortality. The pathogenesis involves complex interactions of autoimmunity, chronic inflammation, and fibrosis. B cells play a central role in these processes through antigen presentation, autoantibody production, cytokine secretion, and the formation of ectopic lymphoid tissue within the lung parenchyma. Rituximab (RTX)-a chimeric anti-CD20 monoclonal antibody-depletes B cells and has emerged as a promising therapeutic agent for CTD-ILD. This review comprehensively presents the immunopathogenic mechanisms underlying CTD-ILD, elaborating on the multifaceted mode of action of RTX and summarizing the evolving clinical evidence.