Interstitial lung disease in patients with anti-neutrophil cytoplasm antibody-associated vasculitis: an update on pathogenesis and treatment

Purpose of review Interstitial lung disease (ILD) is now recognized as a common complication of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV), especially myeloperoxidase (MPO)-ANCA-positive AAV and microscopic polyangiitis (MPA). This review focuses on current concepts pertaining to the pathogenesis, clinical assessment, and management of AAV-ILD. Recent findings ILD is typically identified before or at the onset of systemic AAV, and usual interstitial pneumonia (UIP) is the most common CT pattern. MPO-ANCA production, neutrophil extracellular traps formation, reactive oxidative species production, complement activation, environmental exposures, and genetic background might play a role in the pathogenesis of AAV-ILD. Recent research has identified promising biomarkers as potential diagnostic and prognostic tools in AAV-ILD. The optimal treatment for AAV-ILD is not well defined but might rely on a combination of immunosuppression and antifibrotics, especially in patients with progressive lung fibrosis. Despite the effectiveness of current therapies for AAV, the outcome of patients with AAV-ILD remains poor. Summary ANCA screening should be considered in patients with newly diagnosed ILD. Management of AAV-ILD should be overviewed by a collaborative team comprising vasculitis experts and respirologists. Video abstract http://links.lww.com/COPM/A33