ABH and Lewis antigens on lymphocytes: screening of pregnant women's sera with the B-cell cytotoxicity test.

Five phenotypes related to the ABH-Lewis substances were defined by the B-cell lymphocytotoxic test. These five antigens are built up in a stepwise fashion by the action of the glycosyl transferases specified by the Le, H, and the A, B genes onto the same ABO percursor molecules. The comparison of their chemical structures with the cluster analysis obtained by cytotoxicity suggests that antibodies reacting with large antigenic structures (pentasaccharides) have a more restricted specificity than antibodies reacting only with smaller antigenic determinants (trisaccharides).