Suzuki S, et al. - The clinical features of patients with Mycobacterium avium complex lung disease (MAC-LD) positive for Aspergillus precipitating antibody (APAb) were determined herein. An association of APAb with lower pulmonary function was noted. Furthermore, APAb was detected in particular in patients with longer duration of MAC-LD and severe bronchiectasis, even in the absence of cavitary lesions.