Fluctuation of 6Ckine expression in human endometrium during the menstrual cycle

Abstract

Objective To clarify the expression of 6Ckine, a potential chemoattractant for endometrial natural killer (NK) cells, in the human endometrium. Design Experimental study. Setting Department of obstetrics and gynecology at a medical university. Patient(s) Fifty-seven fertile women 25 to 52 years of age who had regular menstrual cycles and normal endometrium and were undergoing hysterectomy. Intervention(s) Endometrium was obtained from operative samples. Main outcome measure(s) Tissue was immunostained to determine the localization of 6Ckine in the endometrium throughout the menstrual cycle. The number of NK cells was counted in 10 nonoverlapping stromal areas. The concentration of 6Ckine in homogenized endometrium was determined by enzyme-linked immunosorbent assay. Result(s) Endometrial surface, glandular epithelial cells, and perivascular stromal cells were immunoreactive for 6Ckine throughout the menstrual cycle with some fluctuation. In addition, some T cells, NK cells, and macrophages in the stroma were immunoreactive for 6Ckine. The 6Ckine concentration was low in the proliferative phase but elevated in the secretory phase. It showed a moderate positive correlation with the number of endometrial NK cells. Conclusion(s) 6Ckine may be a potential chemoattractant for endometrial NK cells.