BRONCHIECTASIS

Non-tuberculous mycobacteria in patients with bronchiectasis

M Wickremasinghe, L J Ozerovitch, G Davies, T Wodehouse, M V Chadwick, S Abdallah, P Shah, R Wilson

Host Defence Unit, Royal Brompton Hospital, London, UK

Correspondence to:
Dr R Wilson
Host Defence Unit, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK;r.wilson{at}rbh.nthames.nhs.uk

Background: Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms. Patients with pre-existing lung damage are susceptible to NTM, but their prevalence in bronchiectasis is unknown. Distinguishing between lung colonisation and disease can be difficult.

Methods: A prospective study of 100 patients with bronchiectasis was undertaken to evaluate the prevalence of NTM in sputum, and a retrospective analysis of clinical, microbiological, lung function and radiology data of our clinic patients with NTM sputum isolates over 11 years was performed.

Results: The prevalence of NTM in this population of patients with bronchiectasis was 2%. Patients in the retrospective study were divided into three groups: bronchiectasis + multiple NTM isolates (n = 25), bronchiectasis + single isolates (n = 23), and non-bronchiectasis + multiple isolates (n = 22). Mycobacterium avium complex (MAC) species predominated in patients with bronchiectasis compared with non-bronchiectasis lung disease (72% v 9%, p<0.0001). Single isolates were also frequently MAC (45.5%). Multiple isolates in bronchiectasis were more often smear positive on first sample than single isolates (p<0.0001). NTM were identified on routine screening samples or because of suggestive radiology. No particular bronchiectasis aetiology was associated with an NTM. Pseudomonas aeruginosa and Staphylococcus aureus were frequently co-cultured. Six (25%) of multiple NTM patients had cavities of which five were due to MAC. Half the patients with multiple isolates were treated, mostly due to progressive radiology.

Conclusions: NTM are uncommon in non-cystic fibrosis bronchiectasis. Routine screening identifies otherwise unsuspected patients. MAC is the most frequent NTM isolated.

Abbreviations: AFB, acid fast bacilli; FEV₁, forced expiratory flow in 1 second; MAC, Mycobacterium avium complex; MEF₅₀, maximum expiratory flow with 50% of vital capacity remaining in lung; NTM, non-tuberculous mycobacteria; RV, residual volume; TLCO, carbon monoxide transfer factor

Keywords: non-tuberculous mycobacteria; bronchiectasis; Mycobacterium avium complex; lung function

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Sexton, P., Harrison, A. C. (2008). Susceptibility to nontuberculous mycobacterial lung disease. Eur Respir J 31: 1322-1333 [Abstract] [Full Text]  
• Chang, A B, Bilton, D (2008). Exacerbations in cystic fibrosis: 4 {middle dot} Non-cystic fibrosis bronchiectasis. Thorax 63: 269-276 [Abstract] [Full Text]  
• Fowler, S. J., French, J., Screaton, N. J., Foweraker, J., Condliffe, A., Haworth, C. S., Exley, A. R., Bilton, D. (2006). Nontuberculous mycobacteria in bronchiectasis: prevalence and patient characteristics. Eur Respir J 28: 1204-1210 [Abstract] [Full Text]  
• Koh, W-J, Kwon, O J, Wilson, R, Wickremasinghe, M, Ozerovitch, L J, Davies, G, Wodehouse, T, Chadwick, M V, Abdallah, S, Shah, P (2006). Bronchiectasis and non-tuberculous mycobacterial pulmonary infection * Authors' reply. Thorax 61: 458-458 [Full Text]