Faecal interleukin-8 and tumour necrosis factor-α concentrations in cystic fibrosis

Interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α) concentrations were measured in faecal samples from nine patients with cystic fibrosis and nine healthy age matched controls. The patients were assessed with Shwachman score, apparent energy absorption, pancreatic enzyme dosage, simple spirometry, and presence of pseudomonal colonisation. Median (range) wet stool IL-8 and TNF-α concentrations in patients were 32113 pg/g (21656-178128) and 3187 pg/g (368-17611) respectively, compared with <43.5 pg (IL-8)/g (<22-4079) and 99 pg (TNF-α)/g (<0.26-231) in controls. IL-8 concentration was negatively correlated with Shwachman score (r=-0.79) and pancreatic enzyme dosage (r=-0.77), but not with energy absorption. Seven patients were mature enough to cooperate with Their IL-8 concentrations with percentage predicted forced expiratory volume in one second (r=-0.78). IL-8 concentration was greater in four patients with, than five without, established pseudomonal colonisation: median difference 134583 pg/g. TNF-α concentration was not correlated with measures of disease severity. Faecal IL-8 concentration might reflect the severity of pulmonary inflammation in cystic fibrosis and could provide an easily obtainable marker of disease activity.