Susceptibility of Middle Adolescent Females to Sexually Transmitted infections: Impact of Hormone Contraception and Sexual Behaviors on Vaginal Immunity Melissa M. Barousse 1 , Katherine P. Theall 2 , Barbara Van Der Pol 3 , J. Dennis Fortenberry 4 , Donald P. Orr 4 , Paul L. Fidel Jr 1 1 Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA, USA; 2 Department of Epidemiology, Louisiana State University School of Public Health, New Orleans, LA, USA; 3 Division of Infectious Diseases, Indiana University School of Medicine, Indianapolis, IN, USA; 4 Division of Adolescent Medicine, Indiana University School of Medicine, Indianapolis, IN, USA Introduction Adolescent girls represent a menarchal group of females that is newly influenced by reproductive hormones and are also extremely susceptible to sex- ually transmitted infections (STIs); including but not limited to Chlamydia trachomatis (CT), Trichomonas vaginalis (TV), and Neisseria gonorrhoeae (GC). An estimated 3 million adolescents acquire an STI annu- ally in the United States. 1 Although vaginal immu- nity and STIs have been studied frequently in adult women, 2–6 these parameters have been understud- ied in adolescent females. Mucosal immunity has been considered the major contributing factor to host defense in the female reproductive tract and has been described as being independent from the systemic system. 7 Cervical vaginal secretions have been shown to contain Keywords Adolescent behaviors, adolescents, sexually transmitted infections, vaginal immunity Correspondence Paul L Fidel, Jr, Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, USA. E-mail: pfidel@lsuhsc.edu Submitted December 20, 2006; accepted May 9, 2007. Citation Barousse MM, Theall KP, Van Der Pol B, Fortenberry JD, Orr DP, Fidel PL, Jr. Susceptibility of middle adolescent females to sexually transmitted infections: Impact of hormone contraception and sexual behaviors on vaginal immunity. Am J Reprod Immunol 2007; 58:159–168 doi:10.1111/j.1600-0897.2007.00504.x Problem The resistance and ⁄ or susceptibility to infections can be influenced by patterns of immunomodulators. Based on this and the high rate of sexually transmitted infections (STIs) in adolescents, we examined the longitudinal relationship between sexual behaviors, hormonal contra- ceptive use, and bacterial vaginosis (BV) with vaginal-associated immu- nomodulators in adolescent females. Method of study Over 27 months, subjects completed detailed questionnaires, and consented to vaginal swabs for STI testing, and vaginal lavages for iden- tification of immunomodulators including T-helper, proinflammatory, and chemokines. Concentrations of immunomodulators were correlated with each parameter together with prevalence of STIs. Results Each parameter had a limited influence on vaginal immunomodulators with no evidence of any pattern(s) associated with infection. Conversely, the local presence of proinflammatory cytokines and neu- trophils in those with an STI indicated some immune responsiveness. Conclusion Sexual behaviors, contraceptive usage, and BV do not appear as factors in susceptibility of adolescents to STIs through the influence of local immunomodulators. ORIGINAL ARTICLE American Journal of Reproductive Immunology 58 (2007) 159–168 ª 2007 The Authors Journal compilation ª 2007 Blackwell Munksgaard 159