Blood group antigen expression on vaginal and buccal epithelial cells and mucus in secretor and nonsecretor women.

Blood group antigens on epithelial cells may influence bacterial adherence to mucosal surfaces. In the urinary tract the presence of these genetically determined carbohydrate structures may affect bacterial colonization of the vaginal mucosa and subsequent urinary tract infection. In previous studies the detection of ABH and Lewis antigen expression and distribution in tissues have made use of semiquantitative immunohistochemical staining techniques. To determine the pattern and intensity of blood group antigens on epithelial cells and in the mucus overlying them, we developed quantitative immunoassays that use monoclonal antibodies to detect changes in the expression and intensity of ABH and Lewis antigens on cells and in mucus. Vaginal and buccal cell specimens from 23 healthy women (15 secretors and 8 nonsecretors) with no history of urinary tract infections and known blood group types were analyzed for the expression of these antigenic determinants. The profile of ABH antigen expression was generally consistent with the ABO phenotype of the individual and appeared to be influenced by the secretor status; the levels of A, B and H determinants were higher for secretors than nonsecretors. Lewis antigens were detected on vaginal and buccal cells, and mucus. Le(a) and Le(x) antigen expression was greater on cells and mucus from nonsecretors, whereas the expression of Le(b) and Le(y) was greater on cells and mucus from secretors. Variability in antigen expression was observed among individuals with the same blood type and secretor status. The patterns of antigen expression were similar for the vaginal and buccal cell, and mucus samples of an individual but the amount of antigen generally differed for the various samples. These findings document the variation of blood group antigen expression on vaginal epithelial cells and mucus, which may have a significant role in susceptibility to urinary tract infections in women.