Expression of type-2 histo-blood group carbohydrate antigens (Le(x), Le(y), and H) in normal and malignant human endometrium.

Changes in expression of histo-blood group ABH and Lewis antigens are common alterations in carcinomas. Using immunohistochemistry, we have evaluated the expression of type-2 histo-blood group antigens in normal and malignant endometrial tissues in relation to genetic and hormonal factors. The Le(x), sialosyl-Le(x), and Le(y) antigens were inconstantly expressed in the normal endometrium. The expression was uninfluenced by the secretor status but was related to the ABO blood group status in Oestradiol (E2) stimulated endometria. Le(y) was expressed most frequently in proliferating endometria from blood group 0 individuals. Le(x) and Le(y) were maximally expressed in atrophic endometria, and Le(x) and Le(y) staining scores correlated inversely with serum levels of E2 in normal, non-secretory endometria. No correlation was found in adenomatous hyperplasias and endometrial carcinomas, which when compared with atrophic endometria, showed a loss of Le(x) and Le(y) and an increased H-carbohydrate expression at apical membranes. Carcinomas from non-secretors showed lower expression of Le(y) and H-antigens than carcinomas from secretors. Our findings suggest that the genetic and hormonal influence on glycosylation based on type-2 chain carbohydrates differ between normal and malignant endometrium. This difference is probably related to specific tumour-associated qualitative and quantitative changes in the fucosyltransferases.