Sputum Antineutrophil Cytoplasmic Antibodies in Serum Antineutrophil Cytoplasmic Antibody–Negative Eosinophilic Granulomatosis with Polyangiitis

RATIONALE: Eosinophilic granulomatosis with polyangiitis (eGPA) is a small-vessel vasculitis where 40% of patients present with serum antineutrophil cytoplasmic antibodies (ANCAs). We examined the presence and clinical relevance of sputum ANCAs in the serum ANCA^- patients with eGPA. METHODS: ANCA was investigated in matched sputum and blood samples collected from 23 patients with eGPA (n = 10, serum ANCA⁺), 19 patients with eosinophilic asthma …