S. Dionne et al., The effect of inflammation severity and of treatment on the production andrelease of TNF alpha by colonic explants in inflammatory bowel disease, ALIM PHARM, 14(11), 2000, pp. 1435-1442
Background: Despite its pivotal role in mucosal inflammation, data on TNF a
lpha levels in inflammatory bowel diseases have been contradictory.
Aim: To examine TNF alpha production in relation to the type and severity o
f inflammation and therapy, using colonic explant cultures.
Materials and methods: Rectal mucosal biopsies from 271 paediatric patients
(178 inflammatory bowel disease, 27 inflammatory controls, 66 normal) were
cultured for 4 or 18 h. Basal TNF alpha tissue content and release into th
e medium were measured by ELISA and compared to histological severity and c
linical parameters.
Results: TNF alpha release as well as tissue-associated TNF alpha levels we
re significantly increased in rectal biopsies from involved inflammatory bo
wel disease tissue. The amount of TNF alpha correlated with inflammation se
verity scores. TNF alpha levels were higher at 18 compared to 4 h in all gr
oups, whether inflamed or not. TNF alpha released from rectal biopsies was
lower among treated patients at 18 h. The presence of proximal colonic invo
lvement was associated with higher TNF alpha release by uninvolved Crohn's
disease rectal biopsies compared to patients with ileitis alone.
Conclusions: TNF alpha production and release is increased in involved rect
al explants from inflammatory bowel disease. Anti-inflammatory treatment di
minishes this response.