Nontuberculous mycobacteria. II: nested-cohort study of impact on cystic fibrosis lung disease

Am J Respir Crit Care Med. 2003 Mar 15;167(6):835-40. doi: 10.1164/rccm.200207-679OC. Epub 2002 Nov 14.


The prevalence of nontuberculous mycobacteria (NTM) is high (approximately 13%) in sputum of patients with cystic fibrosis (CF), but the impact on lung disease is unknown. We followed 60 incident NTM-positive and 99 culture-negative patients with CF for 15 months and assessed clinical impact of NTM by FEV1 and high-resolution computed tomography (HRCT) of the chest. Mycobacterium avium complex was seen in 75% of NTM-positive subjects. The annual rate of decline in FEV1 was not different among control versus NTM-positive subjects who did not, or did, meet American Thoracic Society microbiologic criteria for NTM disease (3 +/- 1, 3 +/- 2, and 5 +/- 2%, respectively). More subjects with three or more positive cultures for NTM had two or more characteristic findings on entry HRCT (60%, 9/15) as compared with subjects with two positive cultures or less (32%) or negative cultures (19%; p < 0.02). All subjects with three or more positive cultures and exit HRCTs (n = 6) showed progression of HRCT findings, whereas only 17% of subjects with two positive cultures or less had progression (p = 0.0006). In summary, no significant short-term effect on FEV1 was detected in patients with multiple positive NTM cultures, but an abnormal HRCT was predictive of progression. Patients with CF and multiple positive NTM cultures, characteristic HRCT findings, and progression of HRCT changes should be monitored closely and considered for antimycobacterial therapy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Algorithms
  • Case-Control Studies
  • Confounding Factors, Epidemiologic
  • Cross-Sectional Studies
  • Cystic Fibrosis / complications*
  • Cystic Fibrosis / diagnosis
  • Decision Trees
  • Disease Progression
  • Female
  • Forced Expiratory Volume
  • Humans
  • Incidence
  • Longitudinal Studies
  • Male
  • Mycobacterium Infections, Nontuberculous / diagnosis
  • Mycobacterium Infections, Nontuberculous / epidemiology
  • Mycobacterium Infections, Nontuberculous / etiology*
  • Mycobacterium Infections, Nontuberculous / therapy
  • Nontuberculous Mycobacteria / classification
  • Predictive Value of Tests
  • Prevalence
  • Risk Factors
  • Severity of Illness Index
  • Sputum / microbiology
  • Tomography, X-Ray Computed
  • United States / epidemiology