ObjectiveThe study was performed to observe the change of serum levels of high mobility group protein box 1 (HMGB1) in patients with acute pancreatitis (A.P) and to determine its relationship to the severity of AP in order to reveal its clinical significance.MethodsThe serum levels of HMGB1were measured in 50 patients with AP including 24 cases of severe acute pancreatitis (SAP) and 26 cases of mild acute pancreatitis (MAP) in fnst three days after admission.The serum levels of HMGB1 were also detected in 20 healthy volunteers.Furthermore,clinical data of patients was collected and APACHE Ⅱscores were calculated at the time when serum HMGB1 levels were detected to assess the severity of the disease.The 28 day mortality of AP patients was also observed.Then,the relationship between serum HMGB1levels and the severity of AP was analyzed.ConclusionsSerum levels of HMGB1 in patients with AP were significantly positively correlated with APACHE Ⅱ scores.Serum levels of HMGB1 in patients with AP were significantly positively correlated with the 28 day mortality.HMGB1 could be used as an effective indicator to evaluate severity of AP.