Long-Term Course and Prognostic Factors in Pediatric Ulcerative Proctitis: A Multicenter Cohort Study.

Background: Although ulcerative proctitis (UP) in children is considered relatively mild, some patients have proximal disease extension and require immunosuppressive treatment. We investigated clinical characteristics and course of refractory UP in a multicenter pediatric cohort.

Methods: Analyzing data obtained between 2013 and 2022 at 10 institutions specializing in pediatric inflammatory bowel disease, we elucidated natural history and factors predicting a need for immunosuppressive UP treatment. We compared patients given immunosuppressants and/or biologic agents (immunosuppressive treatment group) with those given 5-aminosalicylic acid (5-ASA) alone (5-ASA group).

Results: Fifty-five patients were followed for 3.5 years. The median Pediatric Ulcerative Colitis Activity Index at diagnosis was 20. The commonest treatment, 5-ASA suppository monotherapy in 40% of patients, showed the worst compliance. Clinical remission was achieved at least once in 95% of all patients. Disease extension beyond the splenic flexure occurred in 51%. Immunosuppressive treatment was given to 37%; biologic agents were used for 18%. Rates of endoscopically demonstrated inflammation, including Ra/Rs at diagnosis and extension beyond the left-sided colon, were higher in the immunosuppressive treatment group (70% vs 38%, P < 0.05; 95% vs 27%, P < 0.0001). The log-rank test and multivariate Cox proportional hazards regression showed that time to first clinical remission exceeding 3 months predicted the need for biologics.

Conclusion: The typical initial treatment of pediatric UP was 5-ASA suppositories, despite poor compliance. Biologics or other immunosuppressive treatments were needed in 37% of patients. Close follow-up with adjustment of treatment should be considered in children with UP as its clinical course varies.