Infliximab in the treatment of Crohn's disease :predictors of response in an Italian multicenter open study

Background.: Almost 20% of patients with active Crohn's disease are refractory to conventional therapy. Infliximab is a treatment of proven efficacy in this group of patients and it is not clear which variables predict a good response. Aims.: To evaluate the role of infliximab looking at the predictors of response in a large series of patients with Crohn's disease. Patients and methods.: Five hundred and seventy-three patients with luminal refractory Crohn's disease (Crohn's Disease Activity Index (CDAI) > 220-400) (312 patients) or with fistulising disease (190 patients) or both of them (71 patients) were treated with a dose of 5 mg/kg in 12 Italian referral centres. The primary endpoints of the study were clinical response and clinical remission for luminal refractory and fistulising disease. We evaluated at univariable and multivariable analysis the following variables: number of infusions, sex, age at diagnosis, smoking habit, site of disease, previous surgery, extraintestinal manifestations and concomitant therapies, and type of fistulas. Results.: Patients with luminal refractory disease: 322 patients (84.1%) had a clinical response and 228 (59.5%) reached clinical remission. Patients with fistulising disease: 187 patients (72%) had a reduction of 50% of the number of fistulas and in 107 (41%) a total closure of fistulas was observed. For luminal disease, single infusion (OR 0.49, 95% CI 0.28-0.86) and previous surgery (OR 0.53, 95% CI 0.30-0.93) predicted a worse response for fistulising disease. Other fistulas responded worse than perianal fistulas (OR 0.57, 95% CI 0.303-1.097). Conclusion.: In Crohn's disease infliximab is effective in luminal refractory and in fistulising disease. A single infusion and previous surgery predicted a worse response in luminal disease whereas perianal fistulas predicted a better response than other type of fistulas.