[Effects of low dose mifepristone on population and subsets of natural killer cells in human endometrium during receptive phase].
OBJECTIVE
To investigate the immunologic mechanism of low dose mifepristone as an anti-implantation contraceptive drug.


METHODS
Endometrial biopsies were obtained from fourteen normally cycling women during the receptive phase. Each endometrial tissue, divided into three equal parts, was assigned to three groups: control group, 65 nmol/L mifepristone group (group A) and 200 nmol/L mifepristone group (group B). Endometrial explants were cultured in vitro. The numbers of natural killer cells and the percentages of CD3- CD56+ CD16- subset and CD3- CD56+ CD16+ subset were analysed by immunohistochemistry and flow cytometry.


RESULTS
(1) The mean number of CD56+ NK cells in group A (148 +/- 11) and group B (150 +/- 12) were significantly higher when compared to the control group (121 +/- 7, P < 0.05). There was no significant difference between the two mifepristone-treated groups (P > 0.05). (2) The percentage of CD3- CD56+ Nk cells in group A (44 +/- 5)% and in group B (48 +/- 4)% were significantly higher when compared to the control group (35 +/- 3)% (P < 0.05), there was no significantly difference between the two mifepristone-treated groups (P > 0.05); The percentage of CD3- CD56+ CD16- subset in group A (42 +/- 5)% and in group B (45 +/- 5)% were significantly higher when compared to the control group (33 +/- 3)%, (P < 0.05), there was no significantly difference between the two mifepristone-treated groups (P > 0.05); the percentages of CD3- CD56+ CD16+ subset in three groups [(2.70 +/- 0.24)% (3.26 +/- 0.37)% and (2.33 +/- 0.29)%] were not significantly different (P > 0.05).


CONCLUSIONS
Low dose mifepristones increase the number of CD56+ NK cells and the percentage of CD3- CD56+ CD16- NK subset, which might result in the disturbance of human endometrial immuno-microenvironment during receptive phase and lead to implantation failure.
Zhu
Hong-xia
HX
Department of Family Planning, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
Zhang
Yu-wen
YW
Huang
Li-li
LL
D000021:Abortifacient Agents, Steroidal / Q000494:pharmacology*; D019002:CD56 Antigen / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes; D004717:Endometrium / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007247:Infertility, Female / Q000473:pathology* / Q000517:prevention & control; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000473:pathology; D016131:Lymphocyte Subsets / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D015735:Mifepristone / Q000008:administration & dosage* / Q000494:pharmacology
D000021:Abortifacient Agents, Steroidal; D019002:CD56 Antigen; D015735:Mifepristone