[Behavior of T-lymphocytes during the normal menstrual cycle]

FSH, LH, estradiol-17 beta, progesterone, and T-lymphocytes were examined daily in 12 biphasic cycles of 6 healthy women (age 19-29 years). T-lymphocytes were estimated by the alpha-naphthyl-acetate-esterase-reaction as T-cell-marker. There was a significant reduction of T-cells in the first and a nonsignificant reduction in the second cycle phase. The suppressions were related to the high estradiol levels in the follicular as well as the luteal phase. If there is a causative connection and whether the whole immune system is depressed or other regulatory mechanisms interfere isn't quite clear.