603 - Histological Healing is Associated with Decreased Clinical Relapse in Patients with Ileal Crohn's Disease

NI. Results:The study population consisted of 365 patients.At index endoscopy, 74 patients (20%) had a RS i0, 37 (10%) i1, 91 (25%) i2a, 89 (24%) i2b, 42 (12%) i3 and 32 (9%) i4.During a median (IQR) follow-up of 88 (67-118) months after index endoscopy, CR and NI were observed in 176 (48.2%) and 81 (22.2%) patients, respectively.Patients with an i2 score overall had a 49% risk for CR and a 27% risk for NI.No difference was observed concerning the risk of CR between i2a and i2b patients (44% and 54% respectively, LogRank p=0.31).Risk of NI was not different between i2a and i2b patients (34% and 19% respectively, p=0.11).Probability of CR and NI was significantly higher in patients with an i3 or i4 compared to patients with i0-i2 (Log Rank p<0.001 and p<0.01 respectively).Exposure to antiTNF before surgery, active smoking, a RS i3-i4, or CRP >5 mg/l were independent predictors of CR.A modest but significant decrease of CR risk was observed for patients with a RS i3-i4 when an immunosuppressant or biological therapy was introduced after endoscopy (47% vs. 79%, p=0.03).Among i2a/i2b patients, no difference was observed in terms of CR depending on immunosuppressant or biological therapy initiation after endoscopy (46% vs. 44% in i2 overall cohort) (p=0.46).Conclusion: No difference was observed in terms of CR and NI between patients with RS i2a or i2b.In patients with a RS i2a/i2b, no effect on probability of CR was observed when an immunosuppressant or a biological treatment was initiated after index endoscopy.Intensification of therapy in patients with i3-i4 resulted in significant but modest improvement of clinical relapse risk.