Prediction of the risk of pouchitis based on serum anti-integrin αvβ6 antibody levels at the time of restorative proctocolectomy (RPC). A, Serial changes of serum anti-integrin αvβ6 antibody levels at 3, 6, 9, and 12 months after RPC between patients who developed pouchitis and those who did not (n = 16, the serum samples of 3 out of 16 patients at 3, 6, and 9 months after RPC were not available). At 3, 9, and 12 months after RPC, the serum anti-integrin αvβ6 antibody levels in patients who developed pouchitis were significantly higher than those in patients who did not. *P < .05, **P < .01, Mann-Whitney U test. P = .0336, .0503, .0336, and .0030 (at 3, 6, 9, and 12 months after RPC, respectively). B, Receiver operating characteristic (ROC) curve of serum anti-integrin αvβ6 antibody levels at the time of RPC (n = 13). Area under the curve (AUC) = 0.8333, cutoff value = 106.5 U/mL. The sensitivity and specificity for the onset of pouchitis were 75% and 100%, respectively. C, Kaplan-Meier analysis for pouchitis-free survival probability after RPC. Patients with serum anti-integrin αvβ6 antibody levels above the cutoff value and those below the cutoff value were compared (n = 16). P = .0188, log-rank test. The median period from RPC to the onset of pouchitis in patients with serum anti-integrin αvβ6 antibody levels above the cutoff was 1.954 years.