Antineutrophil cytoplasmic antibody associated microscopic polyangiitis and sinobronchial syndrome.

Antineutrophil cytoplasmic antibodies (ANCA)are well known to be associated with small sized vessel vasculitic diseases such as microscopic polyangiitis (MPA), allergic granulomatous angiitis (AGA), and Wegener's granulomatosis (WG) (1). One subtype is an antibody against myeloperoxidase (MPO), which stains in a perinuclear pattern (P ANCA)by indirect immunofluorescence (IIF) using a neutrophil substrate, and the other subtype is an antibody against proteinase-3 (PR3), which stains in a diffuse granular cytoplasmic pattern (C ANCA)by IIF. PR-3 ANCAis more specific in WGthan the other primary vasculitides. However, MPO-ANCA can be found in MPAand AGAmore frequently than WG.The association of MPAwith MPO-ANCAis reported to be in the range of 4090%, and MPAwith MPO-ANCAis reported to be frequently associated with necrotizing glomerulonephritis and/or pulmonary capillaritis (2). Pulmonary manifestations were observed in 40%, and renal manifestations were observed in 90% of the patients as the initial manifestations, showing that the organs mainly involved in MPAwere the lungs and the kidneys. Pulmonary lesions are more frequently present in anti-PR-3 positive patients, whereas alveolar capillaritis with lung hemorrhage resulting from radiographically hemorrhagic capillaritis is found more frequently in anti-MPO-positive patients (2). In this issue, an analysis is reported by Nagata et al (3) of a very rare MPApatient with a long history of chronic bronchitis and sinusitis (i.e. sinobronchial syndrome) who later evidenced long-standing consolidation in both lungs accompanied with areas of active inflammation.