Clinical significance of red cell blood groups

Abstract

Since the discovery [1] of the ABO blood group system in 1900, more than 400 additional red cell blood group antigens have been identified [2]. Obviously, in a chapter of this length very few of the known complexities can be described. In clinical medicine the major importance of the antigens is the role they play in red cell transfusions. Accordingly, in this chapter an attempt is made to describe the antigens predominantly in that setting. Other aspects of the red cell blood groups as they pertain to certain disease states are mentioned and in some instances brief details about the biochemistry, genetics, serology and immunology of the blood group systems are given in an attempt to make the role of these systems in transfusion therapy more comprehensible. While the stress of the chapter is placed on the role of the blood groups in transfusion, the contributions made from study of the blood groups, in other areas of science, should not be forgotten. Much has been learned about human genetics from studies on how the blood group antigens are inherited. This knowledge is now applied to cases in which parentage is disuputed. By using red and white cell blood group markers it is now possible to exclude individuals from paternity and where no exclusion exists, to use gene frequency calculations to provide strong evidence of parentage. Studies on the biochemical structure of proteins, glycoproteins and glycolipids that carry red blood cell antigens have contributed significantly to the current understanding of the structure and function of cell membranes. The way in which individuals respond to exposure to foreign antigens on red cells has contributed to understandings of the immune system in man. There is no doubt that the survival of renal allografts is considerably better in patients who have been transfused before engraftment than in those who have not. However, this beneficial effect seems to be related to the general immune response to the transfusion of blood (perhaps to the leukocytes contained therein) and not to involve a response to any particular red cell blood group antigen [3]. Accordingly, this subject is discussed in more detail elsewhere in this book.