Clinical Features and Prognosis of Nontuberculous Mycobacterial Pleuritis: A Multicenter Retrospective Study.

The clinical features and prognosis of nontuberculous mycobacterial (NTM) pleuritis and pleural effusion combined with NTM lung disease remain unclear. To investigate the clinical features and prognosis of NTM pleuritis. This retrospective observational study included patients with NTM pleuritis from January 2001 to June 2018 across eight hospitals in Japan. NTM pleuritis was defined by a positive NTM culture of pleural effusion samples. We matched patients with complex (MAC) lung disease (MAC-LD) without pleuritis by sex and age to obtain comparative data and investigated the association between clinical parameters and the prognosis. We identified 64 patients with NTM pleuritis (median age, 73 yr; 37 female patients). The median follow-up duration was 11 months, and 27 patients died. Patients with MAC pleuritis had a significantly lower survival rate than matched patients with MAC-LD without pleuritis. Multivariate analysis revealed that pleuritis (adjusted hazard ratio, 6.99; 95% confidence interval [CI], 2.58-19.00) and underlying pulmonary diseases (adjusted hazard ratio, 3.01; 95% CI, 1.44-6.28) were independently associated with all-cause mortality in patients with MAC-LD. The prognosis of MAC pleuritis is poorer than that of MAC-LD without pleuritis. Pleuritis is an independent prognostic factor in patients with MAC-LD.