To carry out a post hoc analysis of A Crohn 's Disease Clinical Trial Evaluating Infliximab in a New Long-term Treatment Regimen I ( ACCENT I ) to evaluate the association between serum infliximab trough levels and C-reactive protein ( CRP ) after @weeks of induction treatment with durable sustained long-term response ( Crohn 's Disease Activity Index decrease @ points and reduction @ % from baseline ) .