Assessment of Ileoanal Pouch Inflammation by Interleukin 1β and Interleukin 8 Concentrations in the Gut Lumen

Abstract

The cytokines interleukin 1beta and interleukin 8 have previously been shown to be present in mucosal biopsy specimens from inflamed ileoanal pouches. Our aim was to use the method of whole gut lavage fluid to measure cytokine concentrations and relate these to disease activity. Forty-two patients with ulcerative colitis were recruited (23 males). Their ages ranged from 20 to 73 years (median 39). A questionnaire was completed and whole gut lavage, pouchoscopy, and biopsy were performed. Both interleukin 1beta and interleukin 8 were present in the whole gut lavage fluid of ileoanal pouches, with concentrations ranging from 4 to 143 pg/ml (median 6.3 pg/ml) for whole gut lavage fluid interleukin 1beta and from 18 to 1000 pg/ml (median 53.7 pg/ml) for whole gut lavage fluid interleukin 8. Whole gut lavage fluid interleukin 1beta and interleukin 8 were simultaneously detectable in 24 patients. These included the five patients with pouchitis, who had higher levels of interleukin 1beta (75 pg/ml vs. 8 pg/ml, P < 0.005) and interleukin 8 (668 pg/ml vs. 106 pg/ml, P < 0.005) compared with the rest of the patients with detectable cytokines (n = 19). The sensitivity of whole gut lavage fluid interleukin 8 (>200 pg/ml) in the diagnosis of pouchitis was 1, and the specificity was 0.86. There was a significant positive correlation of both whole gut lavage fluid interleukin 1beta and interleukin 8 with all the gut protein loss markers (immunoglobulin G, albumin, alpha1-antitrypsin). Cytokine interleukin 1beta and interleukin 8 concentrations, along with other parameters of inflammation, are raised in pouchitis in the whole gut lavage. The results also suggest a spectrum of severity of "pouchitis," with clinical pouchitis fulfilling Moskowitz criteria at the severe end of the spectrum.