Interstitial lung disease, antineutrophil cystoplasmic antibodies and microscopic polyangiitis

This mini review explores the association of interstitial lung disease (ILD) with antineutrophil cystoplasmic antibodies (ANCA) and the clinical syndrome of microscopic polyangiitis (MPA). Reports on radiographic and histopathologic findings as well as genetic predispositions are reviewed. Based on this evidence a concept for the pathogenesis of the relationship of ILD, MPO-ANCA and MPA is proposed. Finally, a practical clinical management approach to patients presenting either with ILD and a positive ANCA test result, or to patients with MPA found to have pulmonary abnormalities qualifying as an ILD, is derived from the currently available literature. Treatment of these patients is based on up-to-date guidelines for the management of ILD as well as ANCA-associated vasculitis.