Effects of hormone replacement therapy on selected indices of immune function in postmenopausal women

The purpose of this study was to examine the effects of long-term hormone replacement therapy (HRT) on selected indices of resting immune function in postmenopausal women. Postmenopausal women aged 54-66 were divided into two groups, those taking HRT (n = 17) and controls (n = 19). Blood samples were obtained and analyzed for mononuclear cell numbers, lymphocyte proliferation (LP) and natural cell-mediated cytotoxicity (NCMC). There were no significant differences between groups for mononuclear cell numbers. LP was significantly higher for HRT, while NCMC was significantly lower for HRT. HRT is currently being prescribed to postmenopausal women for prevention of a variety of medical conditions including osteoporosis, cardiovascular disease, stroke, and Alzheimer's disease yet HRT is often associated with altered immune parameters. In this study, women taking HRT had increased lymphocyte blastogenesis and decreased NCMC compared to controls.