RECURRENT HEPATITIS-C VIRUS-INFECTION AFTER LIVER-TRANSPLANTATION - IMMUNOHISTOCHEMICAL ASSESSMENT OF THE VIRAL-ANTIGEN

Background: The value of immunohistochemical methods to identify hepat itis C virus antigen (HCVAg) in liver tissue has not been established. We have evaluated the significance of HCVAg expression in livers of p atients with transplants and recurrent hepatitis C virus (HCV) infecti on. Methods: Forty-two liver biopsy specimens from 32 liver-transplant recipients with recurrent HCV infection were tested for HCVAg using f luorescein isothiocyanate-labeled polyclonal, polyreactive human immun oglobulin. Histologic assessment of liver and quantitation of HCV RNA in sera were carried out in specimens obtained simultaneously with bio psies. Results, HCVAg was found in 33% of the liver specimens obtained during the first month after transplantation and in all liver specime ns obtained between 1 and 18 months after transplantation. Amounts of the antigen were significantly greater in specimens obtained more than 1 month after transplantation. A statistically significant increase o f the average HCV RNA level in serum was observed in samples tested af ter the first month after the transplantation, and some decrease in th e HCV RNA level was found in those obtained between 6 and 18 months af ter transplantation, Larger amounts of HCVAg were observed in specimen s corresponding to episodes of acute or chronic hepatitis than in thos e associated with minimal parenchymal evidence of rejection. Conclusio ns: Observations of HCVAg expression in liver biopsy specimens Indicat ed that the presence of Viral antigens in hepatocytes is a constant fi nding in specimens obtained 1 month or longer after transplantation. A lthough large amounts of HCVAg correlated with acute or chronic hepati tis, the nature of this association with the development of pathologic changes remains to be established. Copyright (C) 1998 by the American Association for the Study of Liver Diseases.