Predictors of radiographic progression for NTM–pulmonary disease diagnosed by bronchoscopy

A single isolate of nontuberculous mycobacterium (NTM) from bronchoscopic samples satisfies the microbiological criterion for diagnosing NTM-pulmonary disease (PD). Studies investigating patients with NTM-PD and multiple culture-negative sputum samples but culture-positive bronchoscopic samples are lacking. We investigated the clinical characteristics, outcome, and predictors of radiographic progression in this special population. Patients with negative NTM culture from ≥2 expectorated sputum samples within the 3 months prior to bronchoscopy diagnosis of NTM-PD between 2009 and 2017 were included. Patient characteristics and clinical course were described. Predictors for radiographic progression of NTM-PD within 2 years were analysed by using multivariate logistic regression. Among 66 patients with bronchoscopy-diagnosed NTM-PD, radiographic progression occurred within 2 years in 17 (26%). Of the 60 patients not initially treated, radiographic progression occurred in 17 (28%). Among them, 10 never received treatment, with 6 deteriorating and 3 dying. Of the 6 and 7 patients who received treatment immediately after NTM-PD diagnosis and after radiographic progression, respectively, none had further radiographic progression. The independent predictors of radiographic progression were male sex, body mass index