DUCTULAR STRUCTURES IN ACUTE HEPATITIS WITH PANACINAR NECROSIS

The development of ductular structures in acute hepatitis with panacin ar necrosis was studied in 15 cases of fulminant hepatitis with variab le clinical duration, using immunohistochemical markers. The immunophe notype of ductular structures was assessed by the expression of two bi le duct epithelium determinants, wide spectrum cytokeratin and epithel ial membrane antigen (EMA), and by their glycoconjugate expression usi ng the specific binding lectins Dolichos biflorus agglutinin (DBA) and soybean agglutinin (SEA). Ductular structures showed a predilective, but not a strictly selective location in acinar zone 1 and at the peri phery of newly formed parenchymal nodules. All were positive for kerat in, while EMA and the lectins were identified less frequently. Cytoker atin expression was additionally observed in hepatic cells with no oth er phenotypic alteration: this occurred along isolated hepatic cords, within parenchymal remnants, in the spared parenchyma in acinar zone 1 and occasionally at the periphery of parenchymal nodules. The presenc e of cytokeratin expression in liver cell plates in association with i ntermediate morphological stages of tubular remodelling speaks in favo ur of biliary metaplasia of hepatocytes. This process may represent a phenotypic-functional accommodation of hepatocytes to an altered micro environment, due to loss of parenchymal integrity. During the phenotyp ic shift, altered cytokeratin expression appears as one of the earlies t biliary features, while EMA and the expression of glycoconjugates re present maturation markers.