WP-C3 Modification of the expression of major histocompatibility complex (MHC) antigens during acute rejection of human liver allografts.

J. GUGENHEIM, P. ROUGER, D. SAMUEL, P. GANE, M. CAPRON-LAUDEREAU, H. BISMUTH. Service et Groupe de Recherche de Chirurgie H~patique, HSpital Paul Brousse, VILLEJUIF, FRANCE.

Expression of MHC antigens on liver cellular components may be altered during the course of human liver allografts. The aim of this study is to realize an immunocytochemical analysis of repeated liver biopsies. Percutaneous liver biopsies were carried out, if possible, at day 7, 15, 30 and 60 after transplantation. A total of 75 biopsies were done in 20 patients. Indirect immunofluorescence was performed on frozen sections using monoclonal antibodies directed against B2 microglobulin, class I and class II MHC antigens. The diagnosis of rejection or other hepatic dysfunctions was made confronting clinical, biological and histological data and was confirmed ultimately by the course during therapy. This study shows that in normal liver (45 biopsies) or in biopsies performed at the time of transplantation (17 biopsies) hepatocytes did not express MHC antigens and that small bile duct cells did not express class II antigens although large bile duct cells class II antigens. During acute rejection, we have observed several modifications : cytoplasmic and/or membranous expression of MHC class I antigens on hepatocytes, expression of MHC class II antigens on small bile duct cells. These alterations in the expression of MHC antigens on hepatocytes and bile duct cells were in most cases not present during graft dysfunction from causes other than rejection (infection, cholestasis, ischemia). This study shows alterations in the expression of MHC antigens by liver cellular components during rejection. This modifications could help the diagnosis of rejection.

WP-C 4 SPONTANEOUS HBe SEROCONVERSION IN CHRONIC HEPATITIS B: PREDICTIVE VALUE OF BIOCHEMICAL, PATHOLOGICAL AND IMMUNOHISTOCHEMICAL DATA AT DIAGNOSIS. JM. S&nchez-Tapias, J. Costa, A. Mas, A. Par&s, M. Bruguera and J. Rod,s. Liver Unit. Hospital Clinico y Provincial. Universidad de Barcelona. Spain.

The identification of patients prone to develop spontaneous HBe seroconversion may become important in the management of chronic hepatitis B. In order to investigate the predictive value of data obtained at diagnosis, we have analysed the clinical, biochemical, pathological and immunohistochemical characteristics of 41 HBeAg + patients with chronic hepatitis B. HBcAg was present in liver in all cases and none had delta infection. According to their outcome, patients were separated in Group A, formed by 20 patients who developed typical HBe seroconversion within 12 months and, Group B, formed by 21 patients who remained biochemioally active and HBeAg + 24 months after diagnosis. The mean SGOT and SGPT levels, the histological activity index of Knodell (HAI), the deKree of periportal hepatitis (PH), lobular hepatitis (LH) and liver fibrosis (LF) were significantly hi~her in Group A while the amount of HBcAg in liver was greater in Group B. In addition, significant differences were found in the following qualitative variables:

Biochemistry Liver pathology Liver HBcAg Gr. I N2 GOT~IO0 GPT~I80 HAI~IO PHi4 LH~3 LF=3 ) ++ Focal Cytoplasmic

I 20 12 13 15 ii 12 14 5 18 6 B 21 2 7 6 5 3 7 21 1 1 p 0.001 0.05 0.003 0.05 0.002 0.01 0.001 0.001 0.05

A predictive score index (0 to 9) was constructed from these data: All patients scoring 6 or more (n=13) belonged to group A while all patients scoring 3 or less (n=18) belonged to Group B. These observations suggest that HBe seroeonversion may be predicted in many patients with chronic hepatitis B.

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