Immunological risk factors for HIV acquisition and transmission in post-menopausal women

Problem: Endogenous antimicrobials are part of the first line of defense in the female reproductive tract (FRT) against the sexual transmission of HIV in women. Many of these antimicrobials are regulated by sex hormones and little is known as to whether loss of estradiol in postmenopausal women makes them more susceptible to acquiring and transmitting HIV. Furthermore, it is unknown whether postmenopausal women on hormone replacement therapy (HRT) might recover these antimicrobials. In this study, we investigated the changes in levels of Interleukin-8 (IL-8), Macrophage Inflammatory Protein3-α (MIP3α) and Human Beta Defensin-2 (HBD-2), in genital tract secretions of HIV(-) and HIV(+) postmenopausal women and compared them to premenopausal and postmenopausal women on HRT. Methods: Cervical-vaginal lavage (CVL) samples of HIV(+) and HIV(-) premenopausal, postmenopausal and post-menopausal women on HRT were measured for IL-8, MIP3α and HBD-2 using enzyme-linked immunosorbent assay (ELISA). Statistical analyses were performed using the Kruskal-Wallis test. Results: In the HIV(+) group, IL-8 was significantly reduced in postmenopausal women on HRT compared to premenopausal and postmenopausal women. In the HIV(-) negative group, both MIP3α and HBD-2 were significantly reduced in postmenopausal women compared to premenopausal women. Conclusion: The levels of IL-8, MIP3α and HBD-2 are altered based on hormonal status in HIV(-) and HIV(+) women. Our data suggests HRT might have an effect in genital tract mucosal immune responses against sexually transmitted infections such as HIV. Future experiments are necessary to correlate these levels of endogenous factors in the CVL samples to anti-HIV activity in vitro.