title: Mucosal Blood Group Antigen Expression Profiles and HIV Infections: A Study among Female Sex Workers in Kenya.
abstract: BACKGROUND
  The ABO blood group antigens are carbohydrate moieties expressed on human red blood cells however; these antigens can also be expressed on some other cells particularly the surface of epithelial cells and may be found in mucosal secretions. In many human populations 80% secrete ABO antigens (termed 'secretors') while 20% do not (termed 'non-secretors'). Furthermore, there are disease conditions that are associated with secretor status.
  
  
  OBJECTIVE
  To investigate correlations between secretor status and HIV infection among female sex workers in Nairobi, Kenya.
  
  
  METHODS
  This cross-sectional study recruited 280 female sex workers aged 18-65 years from the Pumwani Majengo cohort, Kenya. Blood typing was determined by serological techniques using monoclonal antibodies to the ABO blood group antigens. Secretor phenotyping was determined using anti-H specific lectins specific to salivary, vaginal and cervical blood group H antigen using the agglutination inhibition technique and correlated to individual HIV sero-status. Participants were additionally screened for Bacterial vaginosis, Neisseria gonorrhoea and Trichomonas vaginalis.
  
  
  RESULTS
  Out of the 280 participants, 212 (75.7%) were secretors and 68 (24.3%) were non-secretors. The incidence of all infections: HIV, Bacterial vaginosis, Neisseria gonorrhoea and Trichomonas vaginalis was higher among secretors compared to non-secretors. However, this difference was only statistically significant for HIV infection incidence rates: HIV infected secretors (83.7%) versus HIV un-infected secretors (71.8%) (p = 0.029) Based on ABO phenotype stratification, the incidence of HIV infection was higher among blood group A secretors (26/52 = 50%), in comparison to B (12/39 = 33.3%: p = 0.066), AB (3/9 = 33.3%: p = 0.355), and O secretors (36/112 = 32.1%: p = 0.028).
  
  
  CONCLUSIONS
  This is the first report to document the variable expression of the ABH blood group antigens profiling secretor and non-secretor phenotypes in the female genital tract among a high-risk population in a Kenyan population. These findings suggest the non-secretor phenotype may confer a certain degree of protection against HIV infection.
authors.affiliation: Institute of Tropical and Infectious Diseases, College of Health Sciences, University of Nairobi, Kenya.
authors.forename: Nadia Musimbi
authors.initials: NM
authors.lastname: Chanzu
authors.affiliation: Institute of Tropical and Infectious Diseases, College of Health Sciences, University of Nairobi, Kenya.
authors.forename: Walter
authors.initials: W
authors.lastname: Mwanda
authors.affiliation: Department of Medical Microbiology, College of Health Sciences, University of Nairobi, Kenya.
authors.forename: Julius
authors.initials: J
authors.lastname: Oyugi
authors.affiliation: KAVI Institute of Clinical Research, College of Health Sciences, University of Nairobi, Kenya.
authors.forename: Omu
authors.initials: O
authors.lastname: Anzala
mesh_terms: D000017:ABO Blood-Group System; D000293:Adolescent; D000328:Adult; D000368:Aged; D001789:Blood Group Antigens / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000276:immunology* / Q000821:virology; D006801:Humans; D015994:Incidence; D007630:Kenya; D008875:Middle Aged; D009092:Mucous Membrane / Q000276:immunology*; D010641:Phenotype; D060386:Sex Workers; D014621:Vagina / Q000276:immunology; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System; D001789:Blood Group Antigens