Predictors of response to infliximab in luminal Crohn's disease.

Aims: To identify predictive factors of response to infliximab in luminal Crohn's disease (CD).

Patients And Methods: All consecutive patients with luminal CD treated with infliximab between October 1999 and March 2003 in Bordeaux's referral centers were included. All had at least 3 months follow-up post infliximab infusion and no prior treatment with infliximab. Response rates were determined 2 and 8 weeks after infusion according to Crohn's Disease Activity Index (CDAI) (remission=CDAI<150 and response=CDAI decrease more than 100).

Results: Among 44 patients (33 female; mean age 35 +/- 14 yr.), 39 (88%) had a clinical response 2 weeks after infusion (79% in remission). At week 8, the rate of response was 61.4% and exclusive colonic involvement predicted sustained response to treatment (P=0.03). The probability of remission at 56 weeks was 21.4%. Multivariate analysis demonstrated that the only factor associated with response duration was initiating immunosuppressive (IS) therapy in women (RR=3.61 95%CI[1.25-10.41], P=0.017).

Conclusion: Exclusive colonic involvement is the only predictive factor of sustained response to infliximab in luminal CD. At the time of infliximab infusion, initiation or modification of IS therapy may favor sustained response, at least in women.