1 Project summary 1.1 Rational. Accent 1 study has demonstrated the superiority of Infliximab over placebo in a systematic treatment strategy of Crohn 's disease every 8 weeks during one year. However the optimal strategy beyond one year of treatment is not established. Particularly, the need for carrying on systematic treatment with infliximab in all the patients has not been demonstrated.||1.2 Primary objective. Determine factors associated with a low risk of clinical relapse after stopping infliximab in CD patients in remission (CDAI<150) and regularly treated with infliximab for at least one year.||1.3 Main objective and main judgement criteria. Determine predictive factors for relapse within one year after stopping infliximab. Main judgement criteria is the clinical relapse after stopping infliximab. Clinical relapse is defined either by a CDAI>250 or by a CDAI between 150 and 250 if this CDAI is confirmed over two consecutive weeks with an increase of at least 70 points over baseline for the two consecutive measures.||1.4 Secondary objectives and judgement criteria. Determine the time to-relapse Determine predictive factors for short-term relapse (<2 months)after stopping infliximab.||Determine response to infliximab retreatment in these patients. Determine tolerance to infliximab retreatment in these patients. Determine predictive factors for an absence of response to retreatment. Determine predictive factors for infliximab retreatment intolerance. Determine sustained response in the retreated patients.||1.5 Type of study Open-label prospective study of stopping regular treatment. Inclusion period: minimum one year, possibly prolonged to reach 100 patients. Patients will be followed up every two months for at least 18 months after stopping infliximab.||1.6 Justification of the number of patients Number of patients to include is at least 100. This recruitment should be reached within one year. This number should allow to disclose predictive factors associated with a relative risk of at least 2 if this factor is equilibrated (50% at risk patients) or 3 is this factor is disequilibrated (90% at risk patients).