Blood group abh‐related antigens in normal and malignant bladder urothelium: Possible structural basis for the deletion of type‐2 chain abh antigens in invasive carcinomas

A complete panel of mouse monoclonal antibodies (MAbs) against Type-2 chain (GaI beta I-4GlcNAc-R) blood-group antigens (N-acetyl-lactosamine, Lex, H, Ley, A monofucosylated, Aley, repetitive A) was used in a detailed immunohistological study of the modulation of these carbohydrate antigens in transitional-cell carcinomas. The histological and cellular locations of these antigens were studied in 19 normal bladder biopsies and 53 transitional-cell carcinomas with as well as without neuraminidase treatment of tissue sections in order to uncover potential sialylated antigens. The antigen expression was correlated to individual A1A2BO, Lewis, and secretor status. Several alterations of blood group expression were found: (1) loss of A and H antigens with accumulation of Ley antigens; (2) loss of correlation between antigen expression and secretor status; (3) disruption of the orderly stratification of blood-group antigen expression in relation to cell layers; and (4) changes in subcellular location of antigen expression. The present data indicate that deletion of Type-2 chain ABH antigens in transitional-cell carcinomas is associated with alpha 1-3 fucosylation of the H antigen leading to accumulation of Ley antigens.