SHIV susceptibility changes during the menstrual cycle of pigtail macaques.
BACKGROUND
Hormonal changes during menstrual cycling may affect susceptibility to HIV.


METHODS
We determined the simian human immunodeficiency virus (SHIV) acquisition time point in 43 cycling pigtail macaques infected by repeated vaginal virus exposures initiated randomly in the cycle.


RESULTS
SHIV infection was first detected in the follicular phase in 38 macaques (88%), and in the luteal phase in five macaques (12%), indicating a statistically significant timing difference. Assuming a 7-day eclipse phase, most infections occurred during or following a high-progesterone period associated with menstruation, vaginal epithelium thinning, and suppressed mucosal immunity.


CONCLUSIONS
This raises questions whether other high-progesterone conditions (pregnancy, hormonal contraception) similarly affect HIV risk.
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Ellen N
EN
Kersh
Tara
T
Henning
Sundaram A
SA
Vishwanathan
Monica
M
Morris
Katherine
K
Butler
Debra R
DR
Adams
Patricia
P
Guenthner
Priya
P
Srinivasan
James
J
Smith
Jessica
J
Radzio
J Gerardo
JG
Garcia-Lerma
Charles
C
Dobard
Walid
W
Heneine
Janet
J
McNicholl
D000818:Animals; D004198:Disease Susceptibility / Q000276:immunology* / Q000821:virology; D005260:Female; D008254:Macaca nemestrina; D008597:Menstrual Cycle / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000502:physiology*; D013997:Time Factors; D014621:Vagina / Q000821:virology
HIV acquisition; HIV risk; hormonal contraception; menstrual cycle; mucosal immunity; reproductive hormone