Interstitial Lung Disease and ANCA-Associated Vasculitis

Abstract

Interstitial lung disease (ILD) in the antineutrophil cytoplasm autoantibodies (ANCA)-associated vasculitides (AAV) is increasingly recognized. The main pattern is that of usual interstitial pneumonia (UIP) mostly occurring in patients who are positive for anti-myeloperoxidase autoantibodies (MPO-ANCA). We touch on some pathogenetic hypothesis concerning how ILD may develop within the AAV, present specific diagnostic items in the context of ILD, discuss the role of imaging in ILD, canvass different scenarios regarding the interplay between ANCA targeting myeloperoxidase (MPO-ANCA) and ILD, and discourse over the current, still not evidence-based treatment for this condition, posing several questions deserving consideration for the design of studies focusing on this unmet need. An increasing number of reports describe patients with antedating ILD to other AAV features. Emerging imaging data is helpful concerning specific areas of lung involvement in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). The approval of specific antifibrotic treatments in lung disease may be helpful in patients with ILD and AAV. Different clinical scenarios concerning ILD, MPO-ANCA, and MPA exist. Clear data on each of these conditions concerning physiopathology, clinical features, and treatment is lacking, but increasing attention is being given to them that may lead to promissory developments.