Role of estradiol and progesterone in HIV susceptibility and disease progression

The Acquired Immunodeficiency Syndrome (AIDS) constitutes the main infectious cause of death in adults worldwide. Epidemiological data suggest the existence of differences in viral load and CD4(+) T lymphocytes cell counts related to gender. Women have more favorable clinical and viro-immunological patterns than men in early infection, although once established the infection these patterns are reversed. Increasing evidence shows that estradiol (E) and progesterone (P) participate in the regulation of several infections, such as that produced by human immunodeficiency virus (HIV). Several functions of these hormones involve the interaction with their intracellular receptors (ER and PR, respectively). During infection, E and P not only exert their action upon the immune system, but also directly act on the virus. Effects of E and P depend on their concentration or the phase of HIV infection but in general terms, they could exert a protective role against HIV infection.