HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan sex workers

AIDS. 1999 Jan 14;13(1):23-9. doi: 10.1097/00002030-199901140-00004.


Objectives: Most HIV-1 transmission is sexual; therefore, immune responses in the genital mucosa may be important in mediating protection against HIV infection. This study examined HIV-1-specific mucosal IgA in a cohort of HIV-1-resistant Kenyan female sex workers.

Methods: HIV-1-specific immune responses were compared in HIV-1-resistant and HIV-1-infected sex workers, and in lower risk uninfected women. Cervical and vaginal samples from each group were tested for HIV-1-specific IgA and IgG by enzyme immunoassay. Systemic T-helper lymphocyte cell responses to HIV-1 envelope peptide epitopes were assayed using an interleukin 2 bioassay. HIV-1 risk-taking behaviours were assessed using standardized questionnaires.

Results: HIV-1-specific IgA was present in the genital tract of 16 out of 21 (76%) HIV-1-resistant sex workers, five out of 19 (26%) infected women, and three out of 28 (11%) lower risk women (P < 0.0001). Among lower risk women, the presence of HIV-1-specific IgA was associated with HIV-1 risk-taking behaviour. Systemic T-helper lymphocyte responses to HIV-1 envelope peptides were present in 11 out of 20 (55%) HIV-1-resistant women, four out of 18 (22%) infected women, and one out of 25 (4%) lower risk women (P < 0.001). T-helper lymphocyte responses did not correlate with the presence or titre of virus-specific mucosal IgA in any study group.

Conclusions: HIV-1-specific IgA is present in the genital tract of most HIV-1-resistant Kenyan sex workers, and of a minority of lower risk uninfected women, where it is associated with risk-taking behaviour. These data suggest a role for mucosal HIV-1-specific IgA responses in HIV-1 resistance, independent of host cellular responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD4 Lymphocyte Count
  • Cervix Uteri / immunology*
  • Cohort Studies
  • Female
  • HIV Antibodies / immunology*
  • HIV Infections / epidemiology
  • HIV Infections / immunology*
  • HIV-1 / immunology*
  • Humans
  • Immunity, Innate / immunology
  • Immunoglobulin A / immunology*
  • Immunoglobulin G
  • Kenya / epidemiology
  • Mucous Membrane / immunology
  • Sex Work*
  • Vagina / immunology*


  • HIV Antibodies
  • Immunoglobulin A
  • Immunoglobulin G