Background : Crohn's disease is complicated by fistulas in 20–40% of patients at some time during the course of their illness. Azathioprine has been reported to heal fistulas in 30–40% of cases. Long-lasting effects by the anti-tumour necrosis factor-α antibody infliximab most often require repeated infusions. Methotrexate has been shown to be an effective drug in maintaining remission in Crohn's disease.

Aim : To evaluate the combination of infliximab and methotrexate as therapy for fistulas in patients with Crohn's disease.

Methods : Twelve consecutive patients (mean age, 29.5 years) with fistulizing Crohn's disease resistant or intolerant to azathioprine were followed prospectively. Patients received three infusions of infliximab (5 mg/kg) and long-term methotrexate (20 mg/week). Therapy success was defined as sustained closure of fistulas ≥ 6 months after fistula closure.

Results : In four of the 12 patients, complete closure of fistulas that persisted for ≥ 6 months (median follow-up, 13.25 months) was observed. In three further patients, a partial response was noted. In five patients, persistent therapy success could not be achieved or therapy had to be stopped due to side-effects.

Conclusions : A combination of infliximab with long-term methotrexate may be a promising concept in fistulizing Crohn's disease. Our data indicate the need for larger controlled trials.