Effectiveness and tolerability of methotrexate monotherapy in Crohn's disease patients: a multicenter observational study.

Background: Methotrexate monotherapy is recommended as a maintenance therapy for Crohn's disease (CD). However, long-term follow-up data are scarce. Objectives: We aimed to examine the effectiveness and tolerability of methotrexate monotherapy in 94 CD patients from three inflammatory bowel disease Clinics in Korea. Design: This was a multicenter retrospective observational study. Methods: Patients with active CD treated with methotrexate monotherapy were included. Clinical characteristics, laboratory indicators, endoscopy indices were evaluated at baseline, 6, 12, and 24 months. Independent factors associated with long-term clinical and endoscopic outcomes were determined. Results: Methotrexate was administered orally (70.2%) or parenterally (29.8%). The mean methotrexate induction dose was 15.3 ± 0.4 mg/week, and the mean duration of therapy was 26.2 months. Of 76 patients who were treated for >6 months, the clinical remission rates were 76.3%, 74.6%, and 80.0% at 6, 12, and 24 months, respectively, by per-protocol analysis. The mean CRP levels were 7.5 ± 1.3, 5.3 ± 1.2, 3.8 ± 0.7, and 2.6 ± 0.5 mg/L at 0, 6, 12, and 24 months, respectively. Of 31 patients who underwent follow-up endoscopy after 27.5 months, the endoscopic remission rate was 38.7%. Baseline hemoglobin level <10 g/dL was a significant independent factor negatively associated with clinical remission at 6 [odds ratio (OR): 0.023, 95% confidence interval (CI): 0.003-0.206, Conclusions: Methotrexate monotherapy was effective and tolerable as a maintenance therapy in CD patients.