Oval cells in hepatitis B virus-positive and hepatitis C virus-positive liver cirrhosis: histological and ultrastructural study

Aims: It is still not clear whether oval cells demonstrate diverse morphology, immunophenotype or quantity in different human liver diseases. The aim of this study was to investigate these differences in hepatitis B virus (HBV)-positive and hepatitis C virus (HCV)-positive human liver cirrhosis (HLC). Methods and results: Thirty-eight cases of HBV+ HLC and 32 cases of HCV+ HLC were investigated by light microscopy and immunohistochemistry for Hepatocyte, CK19, stem cell factor (SCF) and CD34. Five cases were also examined by transmission electron microscopy. Oval cells of similar morphology could be found in proliferating bile ductules in both groups. These cells coexpressed CK19 and Hepatocyte, but did not express SCF or CD34. Some of these cells exhibited a trend towards differentiation. There was no difference in the amount of oval cells between the two groups. The oval cell number was found to increase significantly with the progression of inflammation. A similar stem-like cell was not seen in the normal liver. Conclusions: There are bipotential oval cells in both HBV+ and HCV+ HLC. The lack of difference in oval cells between the two groups suggests that they might play a similar biological role in the histogenesis of different liver diseases.