Changes Of Immune Function And Their Relationship With Levels Of Estradiol And Cortisol In Early Human Pregnancy

Objective: To investigate the regulatory action of estradiol and cortisol on changes of immune function in early human pregnancy. Methods: Early pregnant women (8-10 weeks of gestation) of 14 and healthy non-pregnant women (control) of 10 were used in the present study. T lymphocyte subpopulations in the peripheral blood from these pregnant and non-pregnant women were detected by flow cytometry. Levels of interleukin-4 (IL-4) and interferon-γ(IFN-γ) in the serum were measured by enzyme-linked immunosorbant assay (ELISA). Radioimmunoanalysis was employed to examine levels of estradiol and cortisol in the serum. Results: (1) The percentage of CD3 positive T lymphocytes in the early pregnancy was not significantly different from that in the healthy non-pregnant women (56.94±10.07 vs 62.06±6.51). However, the percentage of CD4~+ T cells and the value of CD4~+/CD8~+ were notably lower in the early pregnancy than in the control (31.18±6.47 vs 37.02± 5.65 and 1.16±0.30 vs 1.58±0.40, respectively). There was no marked difference of CD8~+ cells between the early pregnancy and the non-pregnant women (26.85±4.87 vs 24.19±4.09). (2) The concentration of IL-4 in the serum from the early pregnant women was remarkably increased when compared with that from the non-pregnant women (52.53±12.99 ng/L vs 12.72±7.85 ng/L, P＜0.01). However, there was no dramatic change in IFN-γlevel of the early pregnancy relative to that of the control (12.8±3.48 ng/L vs 9.97±3.66 ng/L). (3) Compared with the non-pregnant women, the early pregnant women had higher levels of estradiol and cortisol in the serum, with 336.33±122.60 pg/ml vs 70.04±22.14 pg/ml for estradiol and 430.59±133.49 pg/ml vs 271.70±104.18 pg/ml for cortisol (P＜0.01). (4) The striking negative correlations existed between the estradiol level and the CD4~+ cell percentage and between the cortisol level and the CD4~+ percentage, with the correlative coefficients-0.5617 for the former and-0.5103 for the latter (P＜0.05). Conclusions: These results show that the changes of immune function in the early pregnant women mainly represent the reduction of help T cells (Th) and the increase of IL-4 secreted by Th2 cells and suggest a shift in the balance of cytokine from Th1-type to Th2-type, which is advantageous to maintaining the normal pregnant development and to preventing the pregnant women from possible rejection to embryo. Importantly, these changes in immune parameters are closely related to the higher levels of estradiol and cortisol, which implies that the hormones are one of crucial factors influencing immune function of early pregnant women. Objective: In the present study, we explored the role of human chorionic gonadotropin (hCG) and immune changes in threatened abortion. Methods: The patients with threatened abortion (8-10 weeks of gestation) of 11 were used in this study. The lymphocyte percentage in leucocytes of peripheral blood was detected by an automatic blood corpuscle counter. The flow cytometry was employed to measure T lymphocytes and their subpopulation in the peripheral blood, and radioimmunoanalysis was used to examine hCG levels in the serum. As control, early normal pregnant women (8-10 weeks of gestation) of 14 and non-pregnant healthy women of 10 were use to test these parameters simultaneously. Results: The lymphocyte percentage in leucocytes of peripheral blood was notably higher in the patients with threatened abortion than in early normal pregnant women (p＜0.01). The percentage of CD3~+ T cells and CD4~+ T cells and the value CD4~+/CD8~+ in the peripheral blood were remarkably increased in the patients with threatened abortion compared with those in early normal pregnant women and non-pregnant healthy women (p＜0.05), but there was no marked difference of CD8~+ cells between them. The women with the threatened abortion had lower levels of hCG in the serum (p＜0.01). A striking negative correlation existed between the hCG level and the CD4~+ cell percentage, with the correlative coefficients-0.667 (P＜0.05). Conclusions: These results show that the occurrence of threatened abortion may be associated with the increase of CD4 positive cells and the decrease of hCG Thus, the increase of CD4 positive cells that is influenced by the decrease of hCG may be one of important factors inducing threatened abortion.