The interleukin 1 receptor antagonist gene allele 2 as a predictor of pouchitis following colectomy and IPAA in ulcerative colitis

Background & Aims: The interleukin I receptor antagonist gene allele 2 has been suggested as a determinant of both disease susceptibility and extent i n ulcerative colitis. The aim of this study was to assess the allele as a p redictor of both the indication for colectomy and the occurrence of pouchit is after ileal pouch-anal anastomosis formation. Methods: Genotyping for th e +2018 single nucleotide polymorphism in the interleukin I receptor antago nist gene was performed in 109 patients who had undergone colectomy, includ ing 82 patients who had been followed prospectively after ilea[ pouch-anal anastomosis formation. Results: Patients with pouchitis had a higher allele 2 carriage rate compared with those without pouchitis (72% vs. 45%) and Ka plan-Meier survival analysis showed that allele 2 carriers had a significan tly increased incidence of pouchitis compared with noncarriers (log-rank te st, 6.5). After adjustment for confounding covariates in a Cox proportional hazards model, the relative hazard was 3.1 (95% confidence interval [CI], 1.2-7.8; P = 0.02). Although there was a higher allele 2 carriage rate in p atients with chronic refractory compared with acute severe ulcerative colit is (63% vs. 48%), this difference was not significant (odds ratio, 1.9; 95% CI, 0.9-4.1; P = 0.1). Conclusions: The interleukin :L receptor antagonist gene allele 2 predicts pouchitis after ileal pouch-anal anastomosis in ulc erative colitis.