Contribution of IL-18 and its related cytokines on the development of hepatic dysfunction in non-biliary acute pancreatitis

Abstract Background : Interleukin-18 (IL-18) production is the main mechanism of hepatic injury in several animal models via further gamma interferon (IFN-γ) release. IL-18 also functions as an inducer of proinflammatory cytokines as TNF-α, which are also shown to induce organ injuries in many severe inflammatory conditions. To clarify the mechanism of hepatic injury developed in acute pancreatitis, plasma concentrations of IL-18 and its related cytokines were analyzed. Patients and methods : Plasma levels of IL-18, IL-12, IFN-γ, TNF-α, soluble TNF receptor (sTNF-R) and soluble Fas ligand (sFas-L) were measured by ELISA. Results : Plasma concentrations of IL-18 in patients with hepatic injury increased during the first few days apparently and remained so to some extent thereafter. However, IFN-γ showed no apparent increase in plasma concentrations. Those of TNF-α and sTNF-R remained increased in the hepatic injury group. Conclusion : These results suggest that IL-18 may act as a pro-inflammatory cytokine, which provokes the cytokine storm and eventually hepatic injury.