Blood Groups and Subgroups of the Newborn

Abstract

Summary Cord blood cells of group B and adult blood cells of group B are agglutinated by native immune anti-B antibodies of human origin practically to the same extent when saline solution is used as the diluent. If physiological saline solution is replaced as the diluent by normal adult serum of group B or group AB, slight differences in agglutinability become apparent. The addition of solutions of the purified B or AB substance to an immune anti-B antibody of human origin, diluted in physiological saline solution, results in the partial or complete neutralization of the antibody content, depending upon the titer of the antibody, on one hand, and the amount of B substance added, on the other. Partially neutralized immune anti-B antibodies regain their capacity for agglutinating B cells when normal adult serum replaces physiological saline solution as the diluent. This reagent reveals considerable differences between adult blood cells of group B and cord blood cells of group B. About half of the cord blood cells that were tested reacted as weakly as might be expected for adult B2 cells, while the other half reacted similarly to but not quite as strongly as adult B1 cells. The differences between the B blood cells of the newborn and the B blood cells of the adult are similar to those which have been found to exist within the blood group A. However, these differences are less impressive from the quantitative point of view than they are in the case of blood cells of group A.