Nontuberculous mycobacteria in diffuse panbronchiolitis.

Background And Objective: Nontuberculous mycobacterial (NTM) lung disease secondary to cystic fibrosis (CF) has been reported, but there is limited data about NTM prevalence in non-CF bronchiectasis. We retrospectively investigated the prevalence of NTM associated with diffuse panbronchiolitis (DPB), a disorder also characterized by reduced mucociliary clearance with bronchiectasis.

Methods: We reviewed mycobacterial cultures, patient characteristics and computed tomography findings of 33 patients with DPB between January 2000 and December 2012. Prevalence was based on at least one positive NTM culture.

Results: Mean patient age was 51.5 years. During a mean 162.8-month follow-up, the prevalence of NTM in sputum was 21.2% (seven patients). Of the seven positive patients, six had Mycobacterium avium complex, one had M. kansasii and M. chelonae co-cultured with M. avium complex. Three patients were positive twice, and two had positive smears. The mean time from DPB diagnosis to the first positive result was 194.6 months. NTM-positive patients tended to have lower forced expiratory volume in 1 s (% predicted) than NTM-negative patients (50.0% vs 77.3%, P = 0.03), but there were no radiological or clinical differences between the two groups.

Conclusions: Our observations suggest that NTM is found more often in DPB. Defects of mucociliary clearance may predispose individuals to NTM infection.