ABO blood group system

The ABO blood group system in humans has three different carbohydrate antigens named A, B, and O. The A antigen sequence is terminal trisaccharide N-acetylgalactosamine (GalNAc)α1-3[Fucα1-2]Galβ-, B is terminal trisaccharide Galα1-3[Fucα1-2]Galβ-, and O is terminal disaccharide Fucα1-2Galβ-. The single ABO gene locus has three alleles types A, B and O. The A and B genes code A and B glycosyltransferases respectively and O encodes an inactive enzyme. A large allelic diversity has been found for A and B transferases resulting in the genetic subgrouping of each ABO blood type. Genes for both transferases have been cloned and the 3D structure of enzymes with and without substrate has been revealed by NMR and X ray crystallography. The ABO blood group system plays a vital role in transfusion, organ and tissue transplantation, as well as in cellular or molecular therapies.     

ABO blood group system

The ABO blood group system in humans has three different carbohydrate antigens named A, B, and O. The A antigen sequence is terminal trisaccharide N-acetylgalactosamine (GalNAc)α1-3[Fucα1-2]Galβ-, B is terminal trisaccharide Galα1-3[Fucα1-2]Galβ-, and O is terminal disaccharide Fucα1-2Galβ-. The single ABO gene locus has three alleles types A, B and O. The A and B genes code A and B glycosyltransferases respectively and O encodes an inactive enzyme. A large allelic diversity has been found for A and B transferases resulting in the genetic subgrouping of each ABO blood type. Genes for both transferases have been cloned and the 3D structure of enzymes with and without substrate has been revealed by NMR and X ray crystallography. The ABO blood group system plays a vital role in transfusion, organ and tissue transplantation, as well as in cellular or molecular therapies.     

ABO blood group system

The accuracy of regular serum methods to detect ABO blood groups can be negatively affected by some factors, such as irregular antibodies, autoantibodies or effects of diseases leading to false or weak agglutination. This study aimed to accurately identify ambiguous ABO blood groups by serological and gene detection methods. The samples were collected in the First Affiliated Hospital of Nanjing Medical University from December 2018 to December 2019. ABO genotyping was performed by polymerase chain reaction-sequence specific primer (PCR-SSP) method in 20 samples, and ABO exons 6 and 7 or FUT1 and FUT2 genes were sequenced in 5 samples. The genes detected in the 21 specimens included 4 cases of A/B, 2 cases of A205/O01, 3 cases of A/O01, 3 cases of A/O02, 1 case of O01/O01, 1 case of O01/O02, 1 case of B/O01, 1 case of B/O02, 1 case of Bel/O01, 1 case of Cisab01/O01, 1 case of rare B/O04, 1 case of Bombay-like Bmh, 1 case of new gene showing c.261del G of exon 6, c.579 T > C of exon 7 and B new/O01. This study suggests that ABO blood group genotyping technology combined with serological typing can be used for accurately typing ambiguous blood groups.     

Molecular characterization of the human ABO blood group orthologus system in pigs

The selection and use of animals with blood group 0 in the process of transplanting pig organs or tissues into humans can positively contribute to the control of acute immune rejection due to differences in blood groups. Exon-specific PCRs for the porcine blood group A transferase gene against genomic DNA from either blood group A or 0 animals resulted in the amplification failure of the A0 blood group gene exon 8 from blood group 0 animals. To characterize the genetic abnormality in the genome of blood group 0 animals, we screened bacterial artificial chromosome (BAC) clones from a Korean native pig BAC library which had the blood group 0 allele, and carried out shotgun sequencing. The analysis showed that the 0 allele has a large deletion between exon 7 of the A0 blood group gene and the neighbouring SURF6. We also showed that the ABO blood group antigens in humans and the A0 blood group antigens in pigs are coded by mutations within the orthologous glycosyltransferase gene. In addition, we developed a multiplex genotyping method for the porcine A0 blood group gene.     

Association of the ABO blood group with certain human diseases

Following the discovery of ABO blood group over 100 years ago, a variety of studies sought to determine whether different disease states are influenced by ABO inheritance. As oligosaccharide antigens, ABO blood group antigens are widely expressed on the membrane of red blood cells and tissue cells, as well as in the saliva and body fluid. It is by far the most important blood group system in human immunohematology and transfusion medicine. While, other than determining blood group phenotype, accumulating evidence indicates that ABO blood group is implicated in the development of a number of human diseases. This review mainly focuses on the association between ABO blood group and cardiovascular system risk, corona virus disease 2019 (COVID-19), affective disorders, allergic diseases, as well as cancers.     

Association between the ABO blood group and the human intestinal microbiota composition

ABSTRACT: BACKGROUND: The mucus layer covering the human intestinal epithelium forms a dynamic surface for host-microbial interactions. In addition to the environmental factors affecting the intestinal equilibrium, such as diet, it is well established that the microbiota composition is individually driven, but the host factors determining the composition have remained unresolved. RESULTS: In this study, we show that ABO blood group is involved in differences in relative proportion and overall profiles of intestinal microbiota. Specifically, the microbiota from the individuals harbouring the B antigen (secretor B and AB) differed from the non-B antigen groups and also showed higher diversity of the Eubacterium rectale-Clostridium coccoides (EREC) and Clostridium leptum (CLEPT) -groups in comparison with other blood groups. CONCLUSIONS: Our novel finding indicates that the ABO blood group is one of the genetically determined host factors modulating the composition of the human intestinal microbiota, thus enabling new applications in the field of personalized nutrition and medicine.