[Relationships between COPD and nontuberculous mycobacteria pulmonary infections]

Nontuberculous mycobacteria (NTM) pulmonary infections are increasingly frequent in pneumological practice. The diagnosis is based on an association of clinical, microbiological and radiological criteria. Some risk factors for NTM disease have been described, including chronic respiratory diseases, but without specific focus on chronic obstructive pulmonary disease (COPD). COPD patients have more risk to be infected by NTM than patients with the main other chronic respiratory diseases (except cystic fibrosis) (odds ratio [OR] at 15.7 in a case-control study). This NTM pulmonary infection is associated with a greater decline in forced expiratory volume in one second (FEV₁) and an increased exacerbation rate. Inhaled corticosteroids (ICS) increase the risk of COPD patients developing an NTM infection (OR at 16.9), especially if ICS are still used at the time of diagnosis. Chronic macrolide treatment could possibly select resistant NTM strains and so could make the treatment clearly more difficult as macrolides are the cornerstone NTM treatment. NTM infections in patients with COPD are probably underestimated and should be kept in mind, particularly when patients have frequent exacerbations and display accelerated respiratory function decline, before implementing ICS or macrolides.