Immunohistochemical study of pre-S(2) antigen in liver and serum of patients with chronic hepatitis B.

To evaluate the significance of pre-S(2) in the liver, the authors studied the relationship between serum and intrahepatic pre-S(2) in 27 patients with chronic hepatitis B. Intrahepatic expression of pre-S(2) was observed under light and electron microscopy and compared with that of HBsAg and HBcAg. All patients were positive for hepatic pre-S(2), and 25 for serum pre-S(2). Intrahepatic pre-S(2) expression was membranous or both membranous and cytoplasmic in 18 cases and was cytoplasmic in 9. The serum levels of pre-S(2) were significantly higher in cases whose intrahepatic pre-S(2) was membranous than in the cytoplasmic cases. These findings indicate that membranous expression of pre-S(2) reflects its secretion into the circulation. Intrahepatic pre-S(2) expression was found almost completely to resemble that of HBsAg on both light and electron microscopy. Membranous pre-S(2) was seen in the liver of 16 of 25 cases who were positive for intrahepatic HBcAg. In detailed studies of membranous pre-S(2) and HBcAg, both membranous pre-S(2) and HBcAg appeared in the liver of all 7 cases before or at the peak of acute exacerbation, but after it, membranous pre-S(2) was not found in 4 of 8 cases. These results suggest that disappearance of membranous pre-S(2) and HBsAg may be related to hepatic cell necrosis in some cases with acute exacerbation.