P541 Can we predict myelotoxicity development during thiopurine therapy for inflammatory bowel disease

Methods: We conducted a retrospective study including patients admitted in our department for severe acute colitis of inflammatory bowel disease (IBD) between 2000 and 2012. Diagnosis of severe acute colitis was made on the basis of Truelove and Witts criteria. Response to cyclosporine therapy was assessed clinically and biologically after 3 and 7 days of treatment and was defined as a Lichtiger score less than 10/20. Statistical analysis was performed with SPSS software version 21.0. Results: One hundred and sixteen patients were referred for severe acute colitis. Cyclosporine was administered in 40 patients after failure of intravenous steroid therapy. There were 18 males and 22 females with a mean age of 31.4 years old (17 55). There were 12 Crohn’s disease cases and 28 of ulcerative colitis cases. Response to cyclosporine was obtained in 20 patients (50%). In univariate analysis, presence of mucosal bridges during initial colonoscopy (p = 0.033), absence of anterior maintenance therapy (p = 0.021) and a decrease of platelet count >65,000/mm3 after 7 days of treatment (p = 0.013) were associated to response to cyclosporine. In multivariate analysis, presence of mucosal bridges during initial colonoscopy was independently associated with response to cyclosporine (p = 0.0001). Conclusions: Cyclosporine is effective in preventing surgery in patients with severe steroid resistant colitis. Response rate of 50% encourages selecting candidates to this treatment with similar benefit in case of Crohn’s disease or ulcerative colitis.