[Modifications of the maternal immune response associated to pregnancy (author's transl)]

Abstract

The author reviews the literature on the immune status of pregnant women. No major alteration of the immune response was observed. If any, the modifications are not important and involve the synthesis of immunoglobulins, the presence of circulating immune complexes, some sub-populations of mononuclear cells and the in vitro lymphocyte response to T dependent antigens. Phagocytosis, the number of B and T cells and mitogen lymphocyte response are normal. Studies on the immuno-suppressive effect of both pregnant women sera and serum substances (hormones, pregnancy associated or specific proteins, carcino-embryonic antigens) are reported. Discrepancies are observed between conclusions drawn by various authors: they relate to the efficiency of the measurement and to the observed effect. The contradictory results obtained with alpha-foetoprotein provide an illustration of the critical analysis of these studies. Finally, the in vivo immune status of pregnant women is reported as observed in cutaneous tests, transplantations and auto-immune diseases. The most relevant observations are: a defect of the expression of delayed hypersensitivity reaction, a facilitating effect of pregnancy in kidney transplantation similar to that obtained after transfusion and an inconstant and mild defect of graft immunity. Therefore, pregnancy produces a specific immune status about which tests presently available give few relevant results, similar to those obtained in some cancers.