Blood Types; Transfusion; Tissue and Organ Transplantation Antigenicity Causes Immune Reactions of Blood Multiplicity of Antigens in the Blood Cells. At least 30
commonly occurring antigens and hundreds of other rare antigens, each of which can at times cause
antigen-antibody reactions, have been found on the surfaces of the cell membranes of human blood
cells. Most of the antigens are weak and therefore are of importance principally for studying the
inheritance of genes to establish parentage. Two particular types of antigens are much more likely than
the others to cause blood transfusion reactions. They are the O-A-B system of antigens and the Rh system.
Agglutinins When type A agglutinogen is not present in a person‘s red blood cells, antibodies known as anti-A agglutinins develop in the plasma. Also, when type B agglutinogenis not present in the red blood cells,
antibodies known as anti-B agglutinins develop in the plasma. Thus, referring once again to Table 35-
1, note that type O blood, although containing no agglutinogens, does contain both anti-A and anti-B agglutinins; type A blood contains type A agglutinogens and anti-B agglutinins; type B blood contains
type B agglutinogens and anti-A agglutinins. Finally, type AB blood contains both A and B
agglutinogens but no agglutinins.
Titer of the Agglutinins at Different Ages.
