ABO blood group system antigens (ABO antigens) (ABO antigens)

The ABO blood group antigens, specifically A and B, are complex carbohydrate structures found on the surface of red blood cells and various other tissues, synthesized by specific glycosyltransferases (NCBI: Gene ID 28). These antigens are defined by the addition of terminal sugar residues—N-acetylgalactosamine for the A antigen and galactose for the B antigen—to a precursor H-substance (StatPearls: NBK554381). They are of paramount importance in transfusion medicine and organ transplantation, as individuals naturally develop antibodies against the antigens they do not express, which can lead to life-threatening immune reactions upon exposure (PubMed: 30033105). Beyond their role in immunology, ABO antigens are associated with susceptibility to various conditions, including increased risk of cardiovascular disease and certain malignancies like gastric and pancreatic cancer (PubMed: 27030377). Therapeutic strategies targeting these antigens include the use of intravenous immunoglobulins to manage ABO-incompatible transplants and the development of enzymatic methods to remove terminal sugars, effectively converting A or B blood types into the universal O type (Nature Microbiology: 4, 1475–1485).

Other names

A antigenB antigenBlood group ABlood group BHisto-blood group ABO systemABO system

Therapeutic approaches involve the neutralization of pre-existing anti-A or anti-B antibodies using intravenous immunoglobulin (IVIG) or plasmapheresis to prevent immune-mediated destruction of red cells or transplanted organs (PubMed: 25108313). Additionally, experimental enzymatic conversion utilizes specific glycosidases, such as alpha-galactosidase and alpha-N-acetylgalactosaminidase, to cleave the terminal immunodominant sugars, thereby transforming A or B antigens into the non-immunogenic H-antigen characteristic of type O blood (Nature Microbiology: 4, 1475–1485).