Cellular and antibody response to respiratory syncytial (RS) virus in human colostrum, maternal blood, and cord blood.

Samples of colostrum, maternal blood, and cord blood from a group of 21 women were examined for the presence of cellular reactivity to respiratory syncytial (RS) virus using a transformation assay and for the level of specific IgA, and IgG, and IgM antibodies to RS virus by membrane immunofluorescence. Six of the 18 colostral cell cultures and six of the 16 maternal blood cultures gave a significant proliferative response to RS virus antigen, although a positive response in both local and systemic cell cultures was found in only one another. In addition, one of 18 samples of cord blood gave a proliferative response to RS virus antigen. Detectable titres of IgA antibodies to RS virus were found in 15 of the 20 samples of colostral whey and in 13 of the 17 samples of maternal plasma examined. RS virus-specific IgG antibodies were detected in 10 of 20 colostral whey samples and in all samples of maternal cord plasma. In this study, it was not possible to demonstrate a relationship between a positive proliferative response of colostral cell cultures to RS virus and the level of specific IgA and IgG antibodies in colostral whey. Similarly, the proliferative response of material blood cultures was unrelated to the titre of specific IgA or IgG antibodies in maternal plasma. The relevance of the local cellular proliferative response to RS virus in colostral cell cultures to the protection afforded by breast-feeding is discussed.