Hepatitis B virus infection of cord blood leukocytes.

The presence of hepatitis B virus (HBV) DNA in the serum and leukocytes obtained from the peripheral blood of 24 mothers and from the cord blood of their newborns was determined by hybridization procedures. HBV DNA was not detected in the serum and leukocytes of six HBsAg-, HBeAg-negative and two HBsAg-positive, HBeAg-negative mothers and their newborn infants. Among the 16 HBsAg-positive carrier mothers, HBV DNA was found in 13 cases (81%) in the serum and in two cases (12%) in leukocytes. Though the viral DNA was not present in sera, it was detected in two of the 16 cord blood leukocyte samples. In follow-up studies, these two infants did not seroconvert up to 15 months of age and they became carriers with elevated serum alanine aminotransferase levels. The results suggest that HBV may be transmitted vertically and such in utero infection may have resulted in immune tolerance leading to a carrier state.