Hepatocyte apoptosis in hepatic iron overload diseases

In this retrospective study, we systematically analyzed hepatocyte apoptosis in three situations of hepatic iron overload (hereditary hemochromatosis; hepatic iron overload of unknown reason; iron overload due to hyperhemolysis or exogenous iron administration). Apoptosis was assessed by use of DNA nick end-labelling. The results suggest that hepatic iron overload is associated with an increased apoptotic rate of hepatocytes, and that iron-laden hepatocytes in hemochromatosis behave, with respect to apoptosis, differently from those in other states of iron overload. The hepatocyte apoptotic rate tended to increase as a function of the degree of iron storage. As in other pathological liver changes studied so far, an elevated apoptotic rate of hepatocytes predominated in the pericentral parts of liver acini in hemochromatosis, but not in the two other groups of hepatic iron overload. Possible mechanisms for this difference are discussed, particularly with respect to a participation of the Kupffer cell system.