MICROSOMAL FUNCTION IN HEPATITIS-B SURFACE-ANTIGEN HEALTHY CARRIERS - ASSESSMENT OF CYTOCHROME-P450 1A2 ACTIVITY BY THE C-14 CAFFEINE BREATH TEST

The hepatitis B surface antigen (HBsAg) carrier state is associated with changes in hepatocellular function involving the cytochrome P450 (CYP) system. Among this system, CYP1A2 enzyme plays an important role in chemical carcinogenesis and in the metabolism of several drugs. We have thus investigated CYP1A2 function using two C-14-caffeine breath tests (3-methyl-C-14; C3BT and 7-methyl-C-14 caffeine; C7BT) in 12 HBsAg healthy carriers and 8 healthy volunteers matched for C-14-aminopyrine breath test values. KBsAg carriers exhibited lower C3- and C7BT values than normal controls. This difference, however, did not reach statistical significance except for C7BT values normalised for aminopyrine breath test values. Our data thus do not support the association between viral presence and CYP1A2 dysfunction.