Immunological changes in pregnancy-induced hypertension.

Aspects of T and B cell function were studied in women with pregnancy-induced hypertension (PIH) and normotensive pregnant women by determining the proliferation of peripheral blood mononuclear cells (PBMC) with or without stimulation by mitogens (PHA, ConA and PWM) and by determining IgG and IgM levels in the culture supernatant. The results showed that the proliferation of PBMC without mitogens was significantly increased in PIH women without proteinuria compared with normotensive pregnant women. In the presence of PHA, [3H]thymidine uptake in PBMC was statistically higher in PIH women both with and without proteinuria than that in normotensive pregnant women. ConA and PWM mitogen activities were not significantly different between PIH women and normotensive pregnant women. Compared with normotensive pregnant women, IgG production was significantly increased in PIH women with proteinuria but not in those without proteinuria. IgM production was not changed in PIH women. We concluded that immunologic responses in PIH women were increased rather than decreased. This increased immunologic activity is in accordance with some important changes seen in PIH, such as an increase in intracellular calcium, the presence of blood-borne mitogenic factor and a decrease in prostaglandin E series. These findings also support the hypothesis that PIH might result from the imbalance between fetal antigenic load and maternal production of immunologic blockade.