Letter: Depression of lymphocyte transformation in women taking oral contraceptives

Immune studies in oral contraceptive users

Some of the parameters of immune status-percentage of B and T lymphocyte subpopulation, PHA-induced lymphocyte transformation measured by 3H-thymidine incorporation (PILT) and levels of total haemolytic complement (CH5O) were studied in Indian women from low income group who were using estrogen-progestogen combination pills. There were no differences in percentage of B and T lymphocyte subpopulation or PILT between OC users and the control group. However, CH5O levels were significantly lower in OC users. The depression in circulating complement levels in OC users is intriguing and suggests the possibility that complement system and circulating immune complexes may be altered in OC users.

The effect of prolactin on the response of human lymphocytes to phytohaemagglutinin

Lymphocytes were collected from ten normal human males and incubated with or without phytohaemagglutinin (PHA) in the absence or presence of ovine prolactin in concentrations found in normal individuals and in human pregnancy. Prolactin consistently inhibited lymphocyte transformations. The degree of inhibition became progressively less as PHA concentrations were increased.

[Immunochemical investigations on the protein of the "pregnancy zone". X. Demonstration of immunosuppressive activities of the pregnancy-associated alpha2-glycoprotein (pregnancy zone protein) by means of the macrophage electrophoretic mobility test (author's transl)]

By means of the macrophage electrophoretic mobility (MEM) test the supposed immunosuppressive activity of the pregnancy-associated alpha2-glycoprotein (pregnancy zone protein) could be demonstrated significantly. Pregnancy sera and sera of nonpregnant women with hormonal contraception containing this pregnancy protein showed an immunosuppresive activity, too. On the contrary, serum of male donors with the blood group AB and human serum albumin had no inhibitory effects. The results suggest that the pregnancy-associated alpha2-glycoprotein rather influences the afferent limb of the immune response and does not interfere with the activity of the mediator (migration inhibiting factor).