Background & aims: Identifying predictors of response to infliximab in Crohn's disease may lead to better selection of patients for this therapy.
Methods: One hundred patients with either inflammatory or fistulous Crohn's disease and at least 3 months of follow-up after infliximab infusion were evaluated. Clinical response and duration of response were the primary outcome measures.
Results: For inflammatory disease, 73% of nonsmokers, compared with 22% of smokers, responded to infliximab (P < 0.001). Among patients taking concurrent immunosuppressives, 74% responded to infliximab compared with 39% not taking any immunosuppressives (P = 0.007). Prolonged response (duration >2 months) was achieved in 59% of nonsmokers compared with 6% of smokers (P < 0.001) and in 65% of patients on immunosuppressives compared with 18% not on immunosuppressives (P < 0.001). For fistulous disease, overall response rates were not different between nonsmokers and smokers, but nonsmokers had a longer duration of response (P = 0.046). Concurrent use of immunosuppressive medications had no effect on rate or duration of response. Multivariable logistic regression analysis confirmed the harmful effect of smoking and the beneficial effect of immunosuppressive use on response in patients with inflammatory disease. The same analysis for fistulous disease did not show an association between smoking or concurrent immunosuppressive use and response to infliximab.
Conclusions: In patients with inflammatory disease, nonsmoking and concurrent immunosuppressive use are associated with higher rates of response and longer duration of response to infliximab. In patients with fistulous Crohn's disease, nonsmoking is associated with longer duration of response to infliximab.