Résumé : OBJECTIVES: Pancreatitis is the most common major complication of endoscopic retrograde cholangiopancreatography (ERCP). Inflammatory cytokines are released during acute pancreatitis. Interleukin-10 (IL-10) is a potent inhibitor of cytokines and has been shown to attenuate pancreatitis in animal models and pilot human studies. This study aimed to determine whether prophylactic IL-10 administration reduces the frequency and/or severity of post-ERCP pancreatitis in high-risk patients. METHODS: A randomized, multicenter, double-blind, placebo-controlled study was conducted. Patients received IL-10 at a dose of either 8 or 20 microg/kg or placebo as a single intravenous injection 15 to 30 minutes before ERCP. Standardized criteria were used to diagnose and grade the severity of postprocedure pancreatitis. RESULTS: A total of 305 of the planned total enrollment of 948 patients were randomized. There was a 15%, 22%, and 14% incidence of post-ERCP pancreatitis in the IL-10 (8 microg/kg), IL-10 (20 microg/kg), and placebo treatment groups, respectively (P = 0.83 for IL-10 8 microg/kg vs placebo and 0.14 for IL-10 20 microg/kg vs placebo). Due to apparent lack of efficacy, the study was terminated at an interim analysis. CONCLUSIONS:: There was no apparent benefit of IL-10 treatment when compared with placebo in reducing the incidence of post-ERCP acute pancreatitis in subjects with increased risk.