Purpose: Non-tuberculous mycobacteria (NTM) are important pathogens in lung transplant recipients. This study describes the spectrum of NTM respiratory tract infections and examines the association of NTM infections with lung transplant complications.
Methods: Data from 208 recipients transplanted from November 1990 to November 2005 were analyzed. Follow-up data were available to November 2010. Lung infection was defined by bronchoalveolar lavage, sputum, or blood cultures in the appropriate clinical setting. All identified NTM respiratory tract infections were tabulated. The cohort of patients with NTM lung infections (NTM+) were compared to the cohort without infection (NTM-). Univariate and multivariate analysis was performed to determine characteristics associated with NTM infection. Survival analyses for overall survival and development of bronchiolitis obliterans syndrome (BOS) were also performed.
Results: In total, 52 isolates of NTM lung infection were identified in 30 patients. The isolates included Mycobacterium abscessus (46%), Mycobacterium avium complex (MAC) (36%), Mycobacterium gordonae (9%), Mycobacterium chelonae (7%), and Mycobacterium fortuitum (2%), with multiple NTM isolates seen on 3 different occasions. The overall incidence was 14%, whereas cumulative incidences at 1, 3, and 5 years after lung transplantation were 11%, 15%, and 20%, respectively. Comparisons between the NTM+ and NTM- cohorts revealed that NTM+ patients were more likely to be African-American and have cytomegalovirus mismatch. Although no difference was seen in survival, the NTM+ cohort was more likely to develop BOS (80% vs. 58%, P = 0.02). NTM+ infection, however, was not independently associated with development of BOS by multivariate analysis.
Conclusion: With nearly 20 years of follow-up, 14% of lung recipients develop NTM respiratory tract infections, with M. abscessus and MAC more commonly identified. M. gordonae was considered responsible for nearly 10% of NTM infections. Although survival of patients with NTM infections is similar, a striking difference in BOS rates is present in the NTM+ and NTM- groups.
Keywords: lung transplantation; non-tuberculous mycobacterium.
© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.