CYTOKINES IN STOOLS OF CHILDREN WITH INFLAMMATORY BOWEL-DISEASE OR INFECTIVE DIARRHEA

Aims-To determine the concentrations of interleukin-6 (IL-6) and tumou r necrosis factor alpha (TNFalpha) in stools from children. Methods-St ool samples from 14 healthy children, 32 children with inflammatory bo wel disease, and 23 children with acute diarrhoea were emulsified in a n equal volume of phosphate buffered saline and then centrifuged to pr oduce a clear supernatant fluid. IL-6 and TNFalpha were measured by en zyme linked immunosorbent assay (ELISA). Results-TNFalpha was detected in the stools of all 14 healthy children (12-130 pg/g stool), but IL- 6 was detected only in three. Similar results were seen in children wi th inactive inflammatory bowel disease. Stool TNFalpha concentrations were raised in samples from children with active inflammatory bowel di sease, but in most (11/18) of these samples IL-6 was undetectable. Sto ol samples contained a heat-labile factor which rapidly destroyed IL-6 immunoreactivity. Most children with diarrhoea had TNFalpha concentra tions similar to those of healthy controls and most were also negative for IL-6. Three children with Shigella flexneri infection had extraor dinarily high concentrations of both TNFalpha and IL-6 in their stools . Conclusions-There is constant low grade production of TNFalpha in th e intestine of healthy people. Raised values are indicative of mucosal inflammation, but are not specific. Stool IL-6 is of little use in as sessing mucosal inflammation because immunoreactivity is rapidly lost in stool samples.