Chronic Mycobacterium abscessus infection and lung function decline in cystic fibrosis

Background: Although nontuberculous mycobacteria (NTM) are recognized pathogens in cystic fibrosis (CF), associations with clinical outcomes remain unclear. Methods: Microbiological data was obtained from 1216 CF patients over 8 years (481 +/- 55 patients/year). Relationships to clinical outcomes were examined in the subset (n=271, 203 +/- 23 patients/year) with longitudinal data. Results: Five hundred thirty-six of 4862 (11%) acid-fast bacilli (AFB) cultures grew NTM, with Mycobacterium abscessus (n=298, 55.6%) and Mycobacterium avium complex (n=190, 35.4%) most common. Associated bacterial cultures grew Stenotrophomonas or Aspergillus species more often when NTM were isolated (18.2% vs. 8.4% and 13.9% vs. 7.2%, respectively, p<0.01). After controlling for confounders, patients with chronic M. abscessus infection had greater rates of lung function decline than those with no NTM infection (-2.52 vs. 1.64% predicted FEV1/ year, p<0.05). Conclusions: NTM infection is common in CF and associated with particular pathogens. Chronic M. abscessus infection is associated with increased lung function decline. (C) 2009 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.