The status of Australia antigen (Au-Ag) and Australia antigen antibody (Au-Ab) was investigated in 27 infants less than 4 months of age with direct reacting hyperbilirubinemia, and in their parents. A diagnosis of viral hepatitis could be excluded in eight infants; of the remaining 19, ten were positive for Au-Ag and another three had suggestive evidence of hepatitis virus B (HBV) infection.
The high proportion of infants with neonatal hepatitis associated with Au-Ag in this series is attributed to the high prevalence of Au-Ag carriers in Greece as well as to the high frequency of exchange transfusions in newborn infants.
The other 14 cases of direct-reacting hyperbilirubinemia, none of which showed Au-Ag or evidence of HBV, were due to congenital malformation of the biliary tract (four cases), septicemia (three cases), cytomegalovirus (CMV) infection (one case), and fructosemia (one case). The remaining five patients, all of whom recovered, are believed to have hepatitis virus A infection.
The detection of Au-Ag in prolonged neonatal jaundice with direct bilirubinemia favors a diagnosis of hepatitis type B, which in our experience carries a graver prognosis reflected in deaths and cirrhosis when compared to neonatal hepatitis not associated with Au-Ag.
In our patients, it is inferred that transmission of Au-Ag to the infants occurred at or after birth, rather than during intrauterine life.
Australia Antigen as a Marker of Propagation of the Serum Hepatitis Virus in Liver Cultures