Humoral and cell-mediated immune responses to herpesvirus antigens during pregnancy--a longitudinal study.

Humoral and cellular immune responses were studied during the second trimester, third trimester, and postpartum periods in 11 pregnant women and in nonpregnant control women. Complement fixing (CF) and indirect hemagglutinating antibody (IHA) titers for herpes simplex type 1 (HSV-1), herpes simplex type 2 (HSV-2), and cytomegalovirus (CMV) were determined. Cellular response was measured by [3H]thymidine uptake by stimulated lymphocytes. Phytohemagglutinin (PHA), HSV-1, HSV-2, and CMV antigens were used as stimulants. No differences in the mean titers of CF and IHA antibodies were found. The cellular response to PHA had a transient decrease (P less than 0.02) during the third trimester. The cellular response to CMV was significantly lower during the second and third trimesters. A diminished response to HSV-1 antigen was observed during the second and third trimesters; the cellular response to HSV-2, though reduced, was not significantly altered during pregnancy. These data indicate a suppression of cellular responses to various herpesviruses and PHA during pregnancy.