MYCOBACTERIAL LUNG-DISEASE IN CYSTIC-FIBROSIS - A PROSPECTIVE-STUDY

Background. Patients with cystic fibrosis (CF) may be predisposed to a irway infections with unusual organisms, such as mycobacteria. The aim of the study was to determine the incidence and clinical picture of m ycobacterial infection in CF children. Methods. At least 2 acid-fast b acillus (AFB) smears and mycobacterial cultures were performed on a pr ospective basis on 682 sputum specimens from 106 patients during a 1-y ear period. Results. Thirty-three percent of the cultures were contami nated with other bacteria. Seven children had at least one sputum cult ure positive for one mycobacterium. Five children had only one positiv e AFB culture. Their clinical status and lung function remained stable during followup. Two teenagers with severe lung disease had several p ositive AFB smears and cultures for Mycobacterium chelonae and Mycobac terium abscessus. The isolation of M. chelonae and M. abscessus was as sociated with a clinical and functional decline. Clarithromycin treatm ent resulted in temporary improvement with the disappearance of the my cobacteria after 6 months of treatment. This prospective study shows a n incidence of 2.3% for positive cultures. The prevalence was 6.6% for mycobacterial colonization but only 1.9% for mycobacterial lung disea se in our pediatric population. Conclusions. We recommend performing A FB smears and cultures in CF children with severe lung disease and/or during a lung exacerbation. In these patients persistence of M chelona e or M. abscessus in sputum should lead to consideration of treatment with clarithromycin.