Hepatitis B antigen and anitbody in maternal blood, cord blood, and amniotic fluid

Prevalence of hepatitis B surface antigen in pregnant mothers and its perinatal transmission

1000 pairs of maternal and cord blood samples were collected simultaneously at the time of delivery. 23 (2.3%) of the maternal samples were positive for HBsAg by enzyme-linked immunosorbent assay. HBeAg was detected in 11 (47%) of the 23 HBsAg positive mothers and anti-HBeAg was detected in another 5 samples. HBsAg and HBeAg were detected in 7 (30%) of the 23 cord blood samples from HBsAg-positive mothers, and anti-HBeAg was detected in one of these samples. At follow-up (6-18 months), antigenaemia had persisted in 17 (85%) of the 20 HBsAg-positive mothers and in 9 (45%) of 20 babies born to HBsAg-positive mothers. Seven of the 10 babies (70%) born to mothers positive for both HBsAg and HBeAg had persistent HBsAg in their blood, in contrast to 2 of the 10 babies (20%) born to mothers positive for HBsAg only. However, none of these mothers or their babies were found to have anti-HBeAg at follow-up. We conclude that the presence of HBeAg in mothers' blood enhances vertical transmission of hepatitis B virus infection to their babies.

Acute hepatitis B in infants born to HBsAG asymptomatic carrier mothers

Within an eight-month period, five cases of acute hepatitis B were observed in children born to asymptomatic HBsAg carrier mothers. At delivery, four mothers were HBeAg-positive and one was anti-HBe-positive. At an average age of 17+/-3 weeks the infants showed high transaminases levels and appearance of markers of HBV infection. Three children became HBsAG chronic carriers, one had a brief HBsAg-antigenemia (1 week), while the last one showed clinical and biochemical signs of hepatitis B in absence of detectable HBsAg but with anti-HBc and anti-HBe (window phase) and later became anti-HBs-positive.

Relationship between the responsiveness of maternal and foetal lymphocytes to phytohaemagglutinin and to microbial antigens

The response of 105 maternal-foetal lymphocyte pairs to specific and non-specific stimulation were evaluated using a newly defined method of analysis. There were no significant differences in the responses of maternal or foetal lymphocytes to phytohaemogglutinin (PHA) or the various antigens as a function of concentration over the ranges tested. The maternal lymphocytes were stimulated by all of the antigens and responded to PHA three--five times more strongly than to the antigens. The foetal lymphocytes were stimulated by PHA and tetanus toxoid only and were suppressed by streptokinase-streptodornase (SKSD). They responded to stimulation by antigens at a lower level than did the maternal lymphocytes, but they responded at a much higher level to PHA. Unstimulated cultures of foetal lymphocytes incorporated more isotope than did those of maternal lymphocytes in both autologous and AB plasma. The data were cross-classified to determine whether the responses of the foetal lymphocytes varied concordantly with the responses of the maternal lymphocytes in both autologous and AB plasma by the Chi-square test for independence and by rank correlation analysis. There was no significant correlation in either plasma to stimulation with the antigens. Thus, the presence of antigen reactive lymphocytes in the circulation of the mother does not mean that the foetus is sensitized to that antigen. Comparison of the lymphocyte responses in autologous plasma with those in AB plasma provided evidence for the presence of circulating immunoregulatory substances. Autologous maternal plasma suppressed the lymphocyte responses to high concentrations of candida and SKSD and stimulated the response to mumps, varicella and tetanus toxoid. Autologous fetal plasma suppressed the lymphocyte responses to candida, varicella and SKSD and stimulated the response to PHA. The responsiveness of maternal lymphocytes to PHA was less in foetal plasma than in autologous maternal or AB plasma.

Transmission of HBsAg from mother to infant in four ethnic groups

Antenatal screening in the West Midlands during a three-year period identified 297 mothers who were chronic carriers of hepatitis B surface antigen (HBsAg)--a prevalence of about 1 in 850. About half of their infants had HBsAg in the cord blood, but of 122 infants followed up for over three months (mean 8.5 months) only 17 (14%) were still positive for HBsAg. Cord-blood HBsAg-positivity was evenly distributed among different ethnic groups, but the transmission rate was highest among the Chinese, and no carriers were discovered among 39 European infants. Raised serum transaminase concentrations were found in some of the carrier infants who were otherwise healthy. The results suggest that adequate follow-up of HBsAg-positive infants may be achieved by tests at 4 months and 1 year of age, and that the role of breast-feeding in mother-to-infant transmission of HBsAg is unimportant. The Chinese community may be a suitable population in which to test the effectiveness of specific immunoglobulin administration at birth in preventing the development of the HBsAg carrier state.

Hepatitis B in children. II. Study of children born to chronic HBsAg carrier mothers

A survey of 4,452 pregnant women taken to find hepatitis B surface antigen revealed 28 asymptomatic chronic carriers. At birth, 16 of 17 infants studied were negative for HBsAg, whereas anti-HBc was present in all patients at a titer similar to that of the mother. Twelve children were followed for 6 to 18 months. In four of them, HBsAg remained negative and anti-HBc titers progressively decreased and were undetectable when tested after the age of 6 months. In eight infants, HBsAg became positive after an average time of 48 days. Elimination of HBsAg occurred in seven infants; five of them had clinical and biological manifestations of mild hepatitis. Sequential determinations of total complement and C components in three patients of the latter group showed dperession of complement at the time of appearance of clinical manifestations. In the patient who became an HBsAg carrier as well as in three infants who remained HBsAg negative, no decrease in complement titers was observed. These results indicate that vertical transmission from carrier mothers can occur in a low prevalence area and that neonatally infected children are capable of active elimination of HBV.