Macrolide antibiotics in diffuse panbronchiolitis and in cystic fibrosis.

I share the interest shown by EVERARD et al. [1] in the use of macrolide antibiotics in cystic fibrosis (CF). Some patients with chronic Pseudomonas colonization do appear to improve when given prolonged courses of azithromycin, and the possibility that this is due to an anti-inflammatory rather than an antibacterial effect is supported by the findings of MOLINARI et al. [2] that subinhibitory concentrations of this antibiotic inhibit pseudomonal virulence factors in vitro. Unfortunately, Everard's preliminary findings of a fall in sputum interleukin (IL)-8 levels with erythromycin treatment would appear to be nonsignificant given that a large study has demonstrated that sputum IL-8 levels in CF patients are log-normally distributed [3] rather than normally distributed as suggested by the figure in Everard's letter. D. Spencer Consultant in Respiratory Paediatrics, Freeman Hospital, High Heaton, Newcastle upon Tyne, NE7 7DN, UK. Fax: 44 191 213 2167