Impact of non-tuberculous mycobacteria on pulmonary function decline in chronic obstructive pulmonary disease.
OBJECTIVE
Although chronic obstructive pulmonary disease (COPD) is a common form of structural lung disease associated with pulmonary non-tuberculous mycobacteria (NTM) infection, no longitudinal studies have investigated the role of NTM in COPD disease progression.


METHODS
From  2000 to 2008, spirometry-confirmed COPD patients with sputum specimens sent for mycobacterial cultures were included. Analysis of clinical, microbiological and pulmonary function data was performed.


RESULTS
The 251 patients were divided into three groups according to the number of NTM  isolates: multiple (n = 47), single (n = 63), and no (n = 141) isolates. Mycobacterium avium complex was the most common species in multiple isolates (36.2%) and single isolate (28.6%) groups. Overall, 24.7% of COPD patients had been admitted for exacerbations at  least once a year, and patients with multiple and single NTM isolates were more than twice as likely as those with no isolate to experience such exacerbations (38.3% vs. 31.7% vs. 17.0%). After controlling for confounders, patients with multiple NTM isolates had a greater decline in forced  expiratory volume in one second than those with single or no isolates (-79.4 ± 32.8 ml vs. -61.6 ± 31.9 ml and -56.2 ± 31.5 ml).


CONCLUSIONS
This study suggests that NTM may play a role in disease progression and deterioration of pulmonary function  in COPD patients.
Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
C-T
CT
Huang
Y-J
YJ
Tsai
H-D
HD
Wu
J-Y
JY
Wang
C-J
CJ
Yu
L-N
LN
Lee
P-C
PC
Yang
D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009165:Mycobacterium Infections, Nontuberculous / Q000382:microbiology* / Q000503:physiopathology; D015269:Mycobacterium avium Complex / Q000302:isolation & purification*; D015270:Mycobacterium avium-intracellulare Infection / Q000382:microbiology / Q000503:physiopathology; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification*; D029424:Pulmonary Disease, Chronic Obstructive / Q000382:microbiology* / Q000503:physiopathology; D012189:Retrospective Studies; D013183:Sputum / Q000382:microbiology