Impact of different subspecies on disease progression in initially untreated patients with Mycobacterium avium complex lung disease.
Clin Microbiol Infect 2020;
27:467.e9-467.e14. [PMID:
32360207 DOI:
10.1016/j.cmi.2020.04.020]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 04/16/2020] [Accepted: 04/19/2020] [Indexed: 11/23/2022]
Abstract
OBJECTIVE
Disease progression is a strong indicator of treatment for Mycobacterium avium complex lung disease (MAC-LD). The impact of MAC subspecies on the risk of disease progression remains uncertain in MAC-LD patients.
METHODS
In this cohort study, we included MAC-LD patients from 2013 to 2018 and classified them into M. intracellulare, M. avium, M. chimaera and other subspecies groups by genotype. We observed the disease progression of MAC-LD, indicated by antibiotic initiation and/or radiographic progression. We used Cox regression analysis to assess predictors for disease progression.
RESULTS
Of 105 MAC isolates from unique MAC-LD patients, 35 (33%) were M. intracellulare, 41 (39%) M. avium, 16 (15%) M. chimaera and 13 (12%) other subspecies. After a mean follow-up time of 1.3 years, 56 (53%) patients developed disease progression: 71% (25/35), 54% (22/41), 31% (4/13) and 31% (5/16) in patients with M. intracellulare, M. avium, others and M. chimaera, respectively. The independent predictors for disease progression were M. chimaera subspecies (HR 0.356, 95% CI (0.134-0.943)), compared with the reference group of M. intracellulare, body mass index ≤20 kg/m2 (HR 1.788 (1.022-3.130)) and initial fibrocavitary pattern (HR 2.840 (1.190-6.777)) after adjustment for age, sex and sputum smear positivity. Among patients without fibrocavitary lesions (n = 94), the risk of disease progression significantly decreased in patients with other subspecies (HR 0.217 (0.050-0.945)) and remained low in those with M. chimaera (HR 0.352 (0.131-0.947)).
CONCLUSIONS
Mycobacterium chimaera was not uncommon in this study; unlike M. intracellulare, it was negatively correlated with disease progression of MAC-LD, suggesting a role of MAC subspecies identification in prioritizing patients.
Collapse