Transmission of circulating schistosomal antigens from infected mothers to their newborns.

Two previous reports have appeared in the literature regarding tansplacental transfer of Schistosoma mansoni antigens which raised the question of its reality. In a previous study the senior author, and others (1992 & 1997) detected circulating antigens of S. mansoni and S. haematobium in infected patients, using monoclonal antibodies 128C3, with a very high sensitivity using ELISA. This work tried to answer the question of antigen transfer possibility using a high sensitive assay in 50 mothers and their newborns at birth and 1, 3, and 6 months after delivery. The assay used in the present work could detect circulating S. mansoni antigens in 45 infected mothers (90%) with active S. mansoni infection. A significant direct increase in mean antigen levels was found with the intensity of infection evaluated by egg counting (p < 0.01). The clinical stage of the diseased mothers was apparently unrelated to the ELISA test values as no significant relations were observed. Positive antigen levels were detected in 33 newborns (66%) of the 45 positive antigen mothers, then the percentage positivity was directly decreased with the advancement of age as only 5 infants (10%) had positive antigen levels compared to 0% at 6 months of age. A positive correlation between newborn serum antigen concentration and concentration of antigen in sera of their mothers was obtained. This work answers some of the questions concerning the ability of the used monoclonal to detect antigens in newborns and the possibility of antigen transfer through the placenta alone or incorporated in immune complexes forms. This work clarifies the time of antigen disappearance from the circulation.