Ono N, Inoue Y, Miyamura T, et al. - In the present study, the researchers sought to examine the correlation of airway comorbidities with the clinical phenotypes and outcomes of myeloperoxidase (MPO)–antineutrophil cytoplasmic antibodies (ANCA)–positive ANCA-associated vasculitis (AAV). Between 2012 and 2018, an AAV patient multicenter cohort trial was established in 13 hospitals in western Japan. A total of 143 new-onset MPO-ANCA–positive AAV patients were studied. Multivariate analysis was conducted to identify factors predictive of remission and death. Twenty-seven cases with granulomatosis with polyangiitis (GPA), 10 with eosinophilic GPA, 81 with microscopic polyangiitis, and 25 with unclassified AAV have been identified. Findings suggested that MPO-ANCA–positive AAV was frequently accompanied by airway comorbidities. Infectious airway comorbidities have been closely associated with those clinical phenotypes and outcomes in addition to fibrotic interstitial lung disease.