Background: It has been shown that perinuclear antineutrophil cytoplasmic antibody (P-ANCA) may be associated with pouchitis after proctocolectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC).
Methods: P-ANCA was studied with the indirect immunofluorescence technique in 76 UC patients after IPAA. Twenty-eight patients had had pouchitis, whereas 48 patients did not.
Results: P-ANCA was found in 49 of 76 (64.5%) UC patients after IPAA. In patients who had had pouchitis attacks within 1 year of serum sampling (group 1) 12 of 12 (100%) patients had positive P-ANCA. In patients who had had pouchitis attacks 1 or several years before the serum sampling (group 2) 9 of 16 (56.3%) patients had positive P-ANCA. In patients who had not yet had a pouchitis attack (group 3) 28 of 48 (58.3%) were positive. The occurrence of P-ANCA in group 1 was significantly higher than in group 2 (p = 0.01) or group 3 (p = 0.005). No statistically significant difference was found between the occurrence of P-ANCA in group 2 and group 3. Furthermore, we found that the titres of P-ANCA in the pouchitis patients were associated with the observation time since the first pouchitis attack to the time of serum sampling (r = -0.43, p = 0.02) and a pouchitis relapse index (average pouchitis attacks per year, r = 0.47, p = 0.03).
Conclusions: P-ANCA was found in UC patients after proctocolectomy with IPAA. Patients with recent (< or = 12 months) or ongoing pouchitis are all P-ANCA-positive. Pouchitis patients with higher P-ANCA titres are more prone to have frequent relapses.