BLOOD-GROUP ANTIGENS ON HUMAN ERYTHROCYTES - DISTRIBUTION, STRUCTURE AND POSSIBLE FUNCTIONS

Human erythrocyte blood group antigens can be broadly divided into carbohydrates and proteins. The carbohydrate-dependent antigens (e.g., ABH, Lewis, Ii, P-1, P-related, T and Tn) are covalently attached to proteins and/or sphingolipids, which are also widely distributed in body fluids, normal tissues and tumors. Blood group gene-specific glycosyltransferases regulate the syntheses of these antigens. Protein-dependent blood group antigens (e.g., MNSs, Gerbich, Rh, Kell, Duffy and Cromer-related) are carried on proteins, glycoproteins and proteins with glycosylphosphatidylinositol anchor. The functions of these molecules on Antigen human erythrocytes remain unknown; some of them A, B, H may be involved in maintaining the erythrocyte shape. This review describes the distribution, structures and probable biological functions of some of these antigens in normal and pathological conditions.