Epidemiologic and biologic characterization of a cohort of human immunodeficiency virus type 1 highly exposed, persistently seronegative female sex workers in northern Thailand. Chiang Mai HEPS Working Group

J Infect Dis. 1999 Jan;179(1):59-67. doi: 10.1086/314556.


Characterization of persons highly exposed to human immunodeficiency virus (HIV)-1 who remain uninfected may help define protective immunity. Seventeen HIV-1-seronegative Thai female sex workers (CSWs) with epidemiologic evidence of exposure to HIV-1 were studied for humoral immune responses and phenotypic and genotypic analyses of HLA class I and CCR5 allelic profiles. Infected CSWs and low-risk HIV-1-seronegative Thai women were controls. Highly exposed, persistently seronegative (HEPS) CSWs did not differ from HIV-infected CSWs in HIV risks, condom use, or sexually transmitted diseases. Significant differences were seen in humoral immune responses: gp160-specific IgA responses were detected in cervicovaginal lavage fluids in 6 of 13 HEPS CSWs but 0 of 21 seronegative subjects. All women had wild-type CCR5. HEPS CSWs were more likely to have the HLA-B18 phenotype and genotype than were matched controls (corrected P=.018). Epidemiologic exposure to HIV-1 without apparent infection, an unusual distribution of HLA class I alleles, and HIV-1 gp160-specific IgA responses suggest a biologic basis for this phenomenon.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Body Fluids / immunology
  • Case-Control Studies
  • Cervix Uteri / immunology
  • Cohort Studies
  • Female
  • Genes, MHC Class I
  • HIV Antibodies / metabolism
  • HIV Envelope Protein gp160 / immunology
  • HIV Infections / epidemiology
  • HIV Infections / immunology
  • HIV Infections / transmission*
  • HIV Seronegativity / immunology
  • HIV-1* / immunology
  • Humans
  • Immunity, Mucosal
  • Immunoglobulin A, Secretory / metabolism
  • Seroepidemiologic Studies
  • Sex Work*
  • Thailand / epidemiology
  • Vagina / immunology


  • HIV Antibodies
  • HIV Envelope Protein gp160
  • Immunoglobulin A, Secretory