The effect of route of delivery on neonatal natural killer cytotoxicity and antibody-dependent cellular cytotoxicity to herpes simplex virus-infected cells.

The ability of human neonatal and adult Ficoll-hypaque purified mononuclear cells to mediate natural killer cytotoxicity (NKC) and antibody-dependent cellular-cytotoxicity (ADCC) against 51Cr labeled herpes simplex virus-infected (HSV-infected) and uninfected cells was evaluated in healthy term infants delivered vaginally or by Cesarean (C)-section without labor, and in healthy adult controls. Cord blood NKC to HSV-infected cells (12.5 +/- 7.0) was lower (P less than 0.01) than adult controls NKC (29.5 +/- 7.0). NKC to HSV-infected cells of babies delivered vaginally (16.6 +/- 3.4) was lower (P less than 0.05) than adult controls (28.4 +/- 4.2). NKC to HSV-infected cells of neonates delivered by C-section without labor (7.6 +/- 2.8) was also lower (P less than 0.001) than adult controls (30.7 +/- 4.0) and lower (P less than 0.05) than that of neonates delivered vaginally. Cord blood ADCC (43.1 +/- 9.0) was lower (P less than 0.05) than ADCC of adult controls (58 +/- 10). ADCC of neonates delivered vaginally (50 +/- 5.9) was similar to ADCC of adult controls (57.4 +/- 6.9). ADCC of neonates delivered by C-section without labor (30.4 +/- 7.2) was lower than ADCC of adult (58.5 +/- 7.4) and was lower (P less than 0.05) than ADCC of neonates delivered vaginally. These findings demonstrate that the method of delivery influences subsequent neonatal leukocyte NKC and ADCC. Further experiments will delineate the cause of these variations, which probably include labor or stress related hormonal changes in the mother or neonate.