Differential Tissue Expression of the Lewis Blood Group Antigens : Enzymatic , Immunohistologic , and Immunochemical Evidence for Lewis a and b Antigen Expression in

The Lewis blood group system comprises two main carbohydrate antigens, Le’ and Leb. Lewis typing has traditionally been based on serologic determinations using erythrocytes and saliva. Several recent studies have demonstrated that erythrocyte Lewis phenotype may change during pregnancy or disease, and inappropriate Lewis antigens have been found in both normal and neoplastic tissue. To evaluate whether these observations are in conflict with the presently proposed genetic and biosynthetic basis of the Lewis blood group system, we performed a combined enzymatic, immunohistologic, and immunochemical study of Lewis antigen expression in normal and neoplastic tissues, as well as erythrocytes, plasma, and saliva of Le(ab-)-typed individu-