Short-term suppression of ovarian function and immune measures in healthy women

Ovarian function was suppressed to postmenopausal levels with a GnRH agonist for four months in healthy, premenopausal women to examine the effect of short-term alterations in sex steroid exposure on immune measures at rest and in response to standardized laboratory stressors. Twenty-two women were assessed at three times: (a) during the early follicular phase of the menstrual cycle; (b) after ovarian function had been suppressed by a GnRH agonist; and (c) either in the early follicular phase after the resumption of regular menstrual cycling (group labeled Cycle), or when women received estradiol transdermally in conjunction with a GnRH agonist (group labeled Patch). A third group of 11 women was assessed at similar time points, but in a different order of pharmacologic intervention to evaluate the effects of ovarian function suppression that were not confounded by habituation to the laboratory stressors (group labeled Hormone Control). Finally, 15 women served as control subjects to control for the effects of time, seasonality and blood collection procedures on immune measures (group labeled Immune Control). Immune measures included circulating cell counts, response to mitogens (PHA and PWM), and NK cytotoxicity. Results revealed no consistent changes in basal or stress-induced immune measures that varied with a period of short-term suppression of ovarian function. Basal and acute stress-induced cell counts showed moderate to high temporal stability over a six to ten month time interval.