ABO blood groups


ABO blood groups

A system of blood grouping developed from the discoveries of Karl Landsteiner (1868–1943) in 1900. The designations are arbitrary and the four groups are A, B, AB and O. These represent the antigenic differences in the red cells, the ANTIGEN being present on the red cell membranes. Group A, B and AB people have A, B and A and B antigens, respectively, on their red cells. Group O people have no antigens and are known as universal donors, whose blood, other things being equal, may safely be transfused into anyone. Group A people (about 26 per cent in Europe) have antibodies (agglutinins) to B in their serum and must not be given blood with B antigens. Agglutinins cause red cells with the same letter antigens to clump together and to become useless. Group B people (about 6 per cent) have antibodies to A in their serum and must not be given blood with A antigens. Group O people (about 68 per cent) have both A and B antibodies, so must not be given either A or B blood. Group AB people have no ABO blood group antibodies in their serum and are known as universal recipients. See also RHESUS FACTOR DISEASE and KELL BLOOD GROUP SYSTEM.

ABO blood groups

A system in which human blood is classified by whether the red blood cells contain A or B antigens. Type A blood has the A antigen; type B has the B antigen, AB has both, and 0 has neither.Mentioned in: Transfusion