Serum interleukin-15 level is a useful predictor of the complications and mortality in severe acute pancreatitis

BackgroundIn severe acute pancreatitis, multiple organ dysfunction syndrome and infectious complications are contributors to high mortality. Interleukin (IL)-15 is a novel cytokine that shares many biologic properties with IL-2. Serum IL-15 levels have not yet been determined in SAP.MethodsSerum IL-15 concentrations were measured in 54 patients with severe acute pancreatitis on admission. The relationships with severity, organ dysfunction, infection, and prognosis were analyzed. Utility of IL-15 for the prediction of clinical outcome was evaluated by receiver operator characteristic (ROC) curve analysis.ResultsSerum IL-15 levels were increased significantly in severe acute pancreatitis (5.8 ± 0.5 pg/mL), and they were correlated with Ranson, APACHE II, and Japanese severity score. Serum IL-15 levels were greater in patients with organ dysfunction, patients with infection, and nonsurvivors (P < 05 each). Incidences of organ dysfunction in patients whose IL-15 levels were less than 3.0, 3.0-5.3, and greater than or equal to 5.3 pg/mL, were 8%, 31%, and 89%, respectively (P < .001). Usefulness of IL-15 for the prediction of organ dysfunction was superior to CRP, IL-6, and IL-8, and it was similar to Ranson, APACHE II, and Japanese severity score. Incidences of infection in patients whose IL-15 levels were less than 5.5, 5.5-9.0, and greater than or equal to 9.0 pg/mL, were 7%, 25%, and 50%, respectively (P < .05). Mortality rates in patients whose IL-15 levels were less than 5.5, 5.5-9.0, and greater than or equal to 9.0 pg/mL, were 11%, 25%, and 80%, respectively (P < .001). Usefulness of IL-15 for the prediction of death was superior to CRP, IL-6, and IL-8.ConclusionsSerum IL-15 level is a useful predictor of the complications (especially organ dysfunction) and mortality in severe acute pancreatitis.