CELL-MEDIATED-IMMUNITY IMBALANCE IN PREGNANCY-INDUCED HYPERTENSION

Pregnancy is associated with modifications in the maternal immune syst em that may be involved in the absence of rejection of the fetoplacent al graft characterized by the presence of paternal antigens. This acti ve and specific tolerance towards the fetoplacental unit seems to be c ompromised in pregnancy induced hypertension (PIH). To evaluate whethe r the immunological state in patients with PIH is altered with respect to normal pregnant women we studied 15 patients with PIH, 15 uncompli cated pregnant and 10 healthy nonpregnant women using monoclonal antib odies directed to specific lymphocyte antigen determinants, cytokines (TNF) and soluble molecules (sIL-2R, sCD8). The percentage of CD4 lymp hocytes and of natural killer (NK) cells was significantly higher in P IH patients compared to controls (CD4: 42.9 +/- 10.5 vs. 32.7 +/- 12.5 %; p < 0.05; NK: 14.7 +/- 6.3 vs. 8.3 +/- 3.4%; p < 0.01). However, th ese values did not differ when compared to normotensive nonpregnant co ntrols (CD4: 53.1 +/- 5.9%; NK: 17.2 +/- 7.1%). In addition, the solub le ILr2 receptor (sIL-2R) was higher in PIH patients when compared to control patients (725.5 +/- 194.2 vs. 482.5 +/- 187.2U/ml; p < 0.01). The immune response observed in normal pregnancies responsible for the tolerance towards the fetoplacental unit seems to be altered in PIH p atients as suggested by higher levels of CD4 and NK cells, and sIL-2R. This may lead to a chronic rejection syndrome and be involved in the pathophysiology of PIH.