Antimicrobial antibodies are associated with a Crohn's disease-like phenotype after ileal pouch-anal anastomosis

Background & aims: Pouchitis and Crohn's disease (CD)-like (CDL) complications of the pouch occur at rates near 50% and 20%, respectively, after colectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). We investigated whether antimicrobial antibodies are associated with pouch outcome after IPAA.

Methods: We studied clinical and endoscopic data from 399 individuals with UC who underwent colectomy with IPAA at Mount Sinai Hospital in Toronto, Canada; patients were classified as no pouchitis (NP), chronic pouchitis (CP), or CDL. Serum samples were analyzed from 341 patients for antibodies against Saccharomyces cerevisiae (ASCA), OmpC, CBir1, and perinuclear antineutrophil cytoplasmic antibody (pANCA).

Results: Of the subjects, 70.7% had NP, 16.8% developed CP, and 12.5% developed CDL. Smoking was associated with CDL (P = .003). Ashkenazi Jewish individuals more commonly had CP (P = .008). Of patients with CDL, 53.5% and 14.0% had positive test results for anti-CBir1 and ASCA (immunoglobulin G), respectively, compared with 21.4% and 3.8% of those with NP and 28.3% and 5.0% of those with CP (P < .0001 and P = .03). Anti-CBir1 was associated with CDL, compared with NP (P = 2.8 × 10(-5); odds ratio [OR], 4.2; 95% confidence interval [CI], 2.2-8.3) or CP (P = .011; OR, 2.9; 95% CI, 1.3-6.6). ASCA immunoglobulin G was associated with CDL, compared with patients with NP (P = .01; OR, 4.1; 95% CI, 1.4-12.3). In a combined model, pANCA and the antimicrobial antibodies were associated with CP (P = .029) and CDL (P = 4.7 × 10(-4)).

Conclusions: Antimicrobial antibodies and pANCA are associated with inflammatory complications of the pouch. The CDL phenotype is associated with factors that characterize Crohn's disease, including smoking, anti-CBir1, and ASCA.