Family history and serology predict Crohn's disease after ileal pouch-anal anastomosis for ulcerative colitis.

PURPOSE: Approximately 5 to 10 percent of patients undergoing ileal pouch-anal anastomosis with a diagnosis of ulcerative colitis are subsequently diagnosed with Crohn's disease. Preoperative predictors for Crohn's disease post-ileal pouch-anal anastomosis have not been prospectively defined.

METHODS

A total of 238 consecutive patients with ulcerative colitis or indeterminate colitis undergoing ileal pouch-anal anastomosis were prospectively enrolled into a longitudinal database. Clinical factors were assessed perioperatively. Serum drawn preoperatively was assayed for anti-Saccharomyces cerevisiae, antiouter membrane porin-C, anti-CBir1, and perinuclear antineutrophil cytoplasmic antibody using enzyme-linked immunosorbent assay. Crohn's disease was defined by small bowel inflammation proximal to the ileal pouch or a perianal fistula identified at least three months after ileostomy closure. Predictors were assessed in a multivariate Cox proportional hazards model to predict the rate of Crohn's disease after ileostomy closure.

RESULTS

Sixteen patients (7 percent) were diagnosed with Crohn's disease; median time to Crohn's disease was 19 (range, 1-41) months. Significant factors for postoperative Crohn's disease after ileal pouch-anal anastomosis included family history of Crohn's disease (hazard ratio, 8.4; 95 percent confidence interval, 2.96-24.1; P < 0.0001) and anti-Saccharomyces cerevisiae immunoglobulin-A seropositivity (hazard ratio, 3.14; 95 percent confidence interval, 1.1-9.81; P = 0.04). Crohn's disease developed in only 8 of 198 patients (4 percent) without these predictors vs. 8 of 40 patients (20 percent) in those with at least one of these factors (P = 0.002). The cumulative risk of Crohn's disease among patients with two risk factors (67 percent) was higher than in patients with either risk factor (18 percent) or neither risk factor (4 percent, P < 0.001).

CONCLUSIONS

Patients with ulcerative colitis and indeterminate colitis with a family history of Crohn's disease or preoperative anti-Saccharomyces cerevisiae immunoglobulin-A seropositivity are more likely to be diagnosed with Crohn's disease after ileal pouch-anal anastomosis.