Immunohistochemical study of hepatitis E virus antigen in liver tissues from patients with hepatitis E.

Hepatitis E virus antigen (HEVAg) has been identified in liver tissue of 6 out of 14 patients with hepatitis E using anti-HEV-IgG-horseradish peroxidase (HRP) and direct immunoperoxidase staining methods. HEVAg was found only in the cytoplasm of hepatocytes, but nor in the nuclei. The HEVAg positive hepatocytes were scattered singly, but in a few parts, where the liver damage was severe, the HEVAg positive cells were quite concentrated. We also observed the invasion of lymphocytes into the HEVAg positive hepatocytes. These phenomena suggest that the liver damage may be related to the immune reaction. No HEVAg was found in the liver tissues of stillborn fetus and neonate from woman patients with hepatitis E.