Association between serum tumor necrosis factor-alpha level and the efficacy of infliximab for refractory pouchitis after restorative proctocolectomy in patients with ulcerative colitis
Department of Inflammatory Bowel Disease, Hyogo College of Medicine, Hyogo, Japan
Objectives: Although the aetiology of pouchitis after restorative proctocolectomy in ulcerative colitis (UC) remains unknown, infliximab (IFX) is often effective for this condition. However, indicators and predictors of treatment efficacy remain unclear. In this study, the association between serum tumor necrosis factor-alpha (TNF-α) levels and refractory pouchitis was evaluated. Methods: We conducted a prospective study between January 2014 and April 2016. Patients with antibiotic-refractory pouchitis were treated with IFX. Serum TNF-α levels were measured before IFX induction. Diagnoses were confirmed using the modified Pouchitis Disease Activity Index (m-PDAI). Responders were defined as patients with an m-PDAI score lower than 5. Recurrence was defined as an m-PDAI score exceeding 5 during maintenance treatment or a need for additional treatments. Associations between serum TNF-α level and efficacy of IFX during 52 weeks of maintenance therapy were evaluated. Results: Thirteen patients were eligible for this study. The short-term efficacy was 8/13 (61.5%). Four patients could not be maintained with IFX alone. The cumulative maintenance ratio was 30.8%/52 weeks, and the cut-off value for serum TNF-α was 1.93 pg/mL for short-term response. Although there was no significant association between serum TNF-α and treatment response, IFX treatment was unsuccessful for all five patients with TNF-α levels below 1.93 pg/mL, including four short-term non-responders and one long-term non-responder. Conclusion: Serum TNF-α level was not an independent predictor of IFX efficacy for refractory pouchitis. However, IFX may be effective for patients with elevated serum TNF-α. Future studies should assess this possibility.