80 HEPATITIS B VIRUS (HBV) CARRIER STATE AND HLA ANTIGENS IN 13 ITALIAN FAMILIES

Abstract

The rate of HBV persistence in the families of our patients affected by Chronic Hepatitis B is much higher (72%) than the chronicity rate reported in the Italian population (10%). AIMS: in order to investigate the possible influence of the major histocompatibility complex upon the course of Hepatitis B infection through a regulation of the host's immune response, we studied the phenotype frequencies of HLA class I and class II antigens in some families. PATIENTS and METHODS: 13 families were studied (56 subjects: 26 parents and 30 children). They all have been infected by HBV: 40 have been positive for HBsAg for longer than 1 year, 16 seroconverted to HBsAb positivity. HLA antigens typing was performed using the standard NIH lymphocyte microlymphocytotoxicity technique. (NIH standard for A and B, NIH long for DR and DQ). RESULTS: DR4, whose protective role against virus persistence has been reported in the literature, is totally absent in our study-group, whereas its frequency in a population of 526 healthy Italian controls (matched for geographical origin) is 18.5%. We used Fisher's exact test to compare the frequencies of HLA determinants in the 40 chronic HBV carriers with those of the 16 seroconverted subjects. A possible protective role was found for DR2 (p= 0.0023), while a possible linkage with HBV persistence was found for A3 (p= 0.011) and B35 (p= 0.020). CONCLUSION: the absence of DR4 and DR2 and the presence of A3 and B35 could play a role in HBV persistence. Further studies are going on to confirm these data in a larger population.