Clustering of HBsAg in a family.

A study was performed on a family of 7 followed up over a 4-year period in which an outbreak of B-antigen-positive hepatitis occurred. Of the 5 male members who acquired HBsAg, 1 became a chronic asymptomatic carrier and 4 had episodes of acute icteric hepatitis during a 15-month period with development of histologically documented chronic hepatitis with persistent HBs antigenaemia in all. Of the 2 female members, 1 had an attack of acute HBsAg-positive hepatitis but recovered normally and cleared HBsAg from her serum, while the other was found to have anti-HBs with no evidence of liver disease. Serological and immunological studies carried out in all members of this family suggested that a sex-linked defect of T cell function itself could explain the differing host immune response to HBV infection in genetically related subjects.