Hepatitis B virus and primary hepatocellular carcinoma: family studies in Korea

Chronic infection with hepatitis B virus (HBV) is closely associated with the etio-pathogenesis of primary hepatocellular carcinoma (PHC). It has been proposed that infection with HBV early in life, frequently transmitted by an HBV-carrier mother, leads to persistent infection with HBV, which in turn is associated with the development of chronic active hepatitis (CAH), post-necrotic cirrhosis and PHC. If this view is correct, then there should be clustering of chronic carriers of HBV in families of patients with chronic liver disease. We tested this hypothesis in Korea by collecting serum from 132 patients with these chronic liver diseases admitted to the Seoul National University Hospital and 664 of their first-degree relatives. Controls (636) were members of two churches in Seoul and a rural village population; 261 of the controls were between the ages of 30 and 59, the age range that included 95% of the cases of chronic liver disease. Sera were assayed for hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs) and antibody to hepatitis B core antigen (anti-HBc). Almost all cases showed evidence of present or past infection with HBV; 80% were HBsAg(+) and 14% were anti-HBs(+); 100% of 47 cases of PHC, 100% of 35 cases of cirrhosis, and 94% of 50 cases of CAH were anti-HBc(+); 6% of males and 4% of females in control population (30-59 years of age) were HBsAg(+), 71% were anti-HBc(+), and 51% were anti-HBs(+). HBsAg(+) patients with chronic liver disease tended to be younger than HBsAg(-) patients with anti-HBs or anti-HBc antibodies. Mothers of patients with more frequently (HBsAg(+) (9 of 33) than age-matched women in the control population (0 of 34) or wives of patients (5 of 68). Five of 23 fathers were also HBsAg(+) compared with 1 of 25 age-matched controls. As first observed in Africa, there was a deficit of anti-HBs in the fathers of cases compared with the controls. Siblings of patients were frequently HBsAg(+) (45% of 154), with the highest prevalence in brothers (53%). Family history shows that five fathers, two mothers and five brothers of cases have died of PHC. These data are compatible with the hypothesis tested and lend further support to the view that prevention of infection with HBV will lead to a marked decrease in the incidence of CAH, cirrhosis and PHC in areas where these diseases are endemic. Members of the families of patients with these diseases are at high risk of developing persistent infection with HBV and chronic liver disease. It would be appropriate to focus preventive strategies on infants and children in such families.