Fistula response to methotrexate in Crohn's disease: A case series

Background: Controlled trials have demonstrated the efficacy of methotrexate in the induction and maintenance of remission in luminal Crohn's disease; however, its effect on fistulizing disease is unknown. Aim: To describe the response to methotrexate therapy in a series of patients with fistulizing Crohn's disease. Methods: A retrospective chart review was conducted of all patients with Crohn's disease receiving methotrexate in one practice. The response of patients with fistulizing and luminal disease was assessed using clinical and laboratory criteria. Fistula response was categorized as either complete or partial closure. Results: Thirty-seven courses of methotrexate therapy were given to 33 patients with luminal and/or fistulizing Crohn's disease. In 16 patients with fistulas, four (25%) had complete closure, five (31%) had partial closure and all had failed or were intolerant to 6-mercaptopurine therapy. Overall, response to methotrexate was seen in 23 of 37 (62%) treatment courses in patients with luminal and/or fistulizing Crohn's disease. Two of the 33 patients (6%) had a significant adverse event. Conclusions: In this case series, 56% of patients with Crohn's fistulas on methotrexate showed a complete or partial response to therapy. Further studies are needed to confirm the role of methotrexate alone, and in combination with other therapies, for the treatment of fistulizing Crohn's disease.