Eosinophils involved in fulminant hepatic failure are associated with high interleukin‐6 expression and absence of interleukin‐5 in liver and peripheral blood

Background/Aims: Although eosinophils are considered to play an important role in the pathogenesis of various parasitic, allergic and autoimmune digestive diseases, their role in fulminant hepatic failure (FHF) is unknown. Our contribution was to identify and quantify eosinophils and cytokine levels [interleukin (IL)‐6, IL‐5 and macrophage inflammatory protein (MIP)‐1α] in liver parenchyma and peripheral blood from FHF patients at pre‐ and post‐transplantation steps. Methods: Histochemical methods were used to identify/quantify eosinophils in liver samples. Liver and plasma cytokine levels were quantified using immunofluorescence methods. Results: Fulminant hepatic failure patients showed a high number of intrahepatic eosinophils concomitant with an increased expression of IL‐6, besides the IL‐6‐positive eosinophils associated with the lack of IL‐5. Also, an increased number of eosinophils and soluble IL‐6 and MIP‐1α with a low expression of IL‐5 in peripheral blood at the pretransplantation step was observed. Conclusions: The increased number of intrahepatic eosinophils, besides the high production of IL‐6, may be involved in liver dysfunction. In addition, the low presence of IL‐5 in liver and peripheral blood may represent a particular pattern of eosinophil behaviour in human liver failure, which may also involve MIP‐1α. Further ex vivo studies are necessary to evaluate the specific role of eosinophils in FHF.