Thiopurine treatment in inflammatory bowel disease:Response predictors, safety, and withdrawal in follow-up

Background and aims: Thiopurines represent the mainstay of immunosuppressive therapy in inflammatory bowel diseases. Since it is likely that response to therapy and adverse events depends on the genetic background of patients our study aimed to evaluate retrospectively response to therapy and safety in a mixed IBD population in Southern Europe. Methods: We evaluated demographic and clinical data of our patients treated with thiopurines. after 6 months in responders and non-responders to therapy. Moreover the likelihood to remain in thiopurine monotherapy was evaluated in responders, whereas adverse events were investigated in all patients. Results: Among disease- and patient-related parameters a shorter disease duration, female gender and ileal disease in Crohn's patients were associated with better response. By ROC analysis, the best predictors of response were decreasing values of C-reactive protein and erythrocyte sedimentation rate. In the long-term more than half of IBD patients who responded at 6 months remained on monotherapy at 42 months. Flu-like syndrome represented the most frequent adverse event followed by abnormalities of liver function tests and myelotoxicity. Adverse events did occur at any time and were frequently impredictable. Conclusions: In this retrospective study, thiopurines showed a good clinical efficacy, especially in patients with short duration of disease. Normalization of markers of systemic inflammation