The Effectiveness and Safety of Methotrexate as the First-Line Immunomodulator of Maintenance Therapy in Pediatric Crohn Disease

Objectives:Methotrexate (MTX) has been used as maintenance therapy for Crohn disease (CD) in adults and children. However, there are only a few studies on the MTX's effectiveness in thiopurine-naive CD adult patients and children. This study aimed to evaluate the MTX's effectiveness and safety as first immunomodulator for maintenance therapy in pediatric CD. Methods:This retrospective cohort study recruited 64 pediatric CD patients treated with MTX as a first-line immunomodulator. Clinical remission (CR) was assessed at weeks 14, 26, and 52. Mucosal healing (MH) was assessed at weeks 26 and 52. Results:Of 64 patients who received MTX, CR was noted in 60.9% at week 14, 29.7% with MH in 68.0% at week 26, and 27.8% with MH in 81.8% at week 52. When comparing age subtypes according to the Paris classification, the CR rate was higher in A1a than in the other subtypes at week 26 (60.0% in A1a, 26.5% in A1b, 0% in A2; P = 0.038). There were no differences in disease location, behavior, or perianal involvement. Adverse effects were noted in 30 of 64 (46.9%) patients, including 1 patient who stopped MTX before 26 weeks owing to side effects; increased liver enzymes in 25 (39.0%) patients, leukopenia in 5 (7.8%), nausea in 5 (7.8%), skin erosion in 1 (1.6%), and headache in 1 (1.6%). Conclusion:MTX as a first-line immunomodulator may be an effective and safe maintenance therapy for pediatric CD patients.