Classification systems consisting of a set of blood antigens, chosen for blood typing
For an overview of the main blood types and their clinical significance, see Blood type.
The term human blood group systems is defined by the International Society of Blood Transfusion (ISBT) as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more very closely linked homologous genes with little or no observable recombination between them",[1] and include the common ABO and Rh (Rhesus) antigen systems, as well as many others; 44 human systems are identified as of 31 December 2022[update].[2]
Illustrates potential antigenicity of low abundance membrane proteins and contributes to understanding of in vivo characteristics of the Piezo1 protein in transfusion biology
Antibodies
Following is a comparison of clinically relevant characteristics of antibodies against the main human blood group systems:[10]
Other human blood group systems than ABO and Rh have a relatively small risk of complications when blood is mixed.[16] Therefore, in emergencies such as major hemorrhage, the urgency of transfusion can exceed the need for compatibility testing against other blood group systems (and potentially Rh as well).[16] Also, blood compatibility testing beyond ABO and Rh is generally limited to antibody detection (not necessarily including forward typing). Still, in Europe, females who require blood transfusions are often typed for the K and extended Rh antigens to prevent sensitization to these antigens, which could put them at risk for developing hemolytic disease of the newborn during pregnancy.[17]
When needing to give red blood cell transfusion to a patient, the presence of clinically significant antibodies produced by the patient can be detected by mixing patient serum with 2 to 4 "screening" or "control" red blood cells that together display essentially all relevant antigens. If any of these mixes display a reaction (evidence of patient antibodies binding to the screening red blood cells), a more extensive antibody panel is warranted (as imaged at right).[18]
^ abHelias, V.; Saison, C.; Ballif, B.A.; Peyrard, T.; Takahashi, J.; Takahashi, H.; Tanaka, M.; Deybach, J.C.; Puy, H.; Le Gall, M.; Sureau, C.; Pham, B.N.; Le Pennec, P.Y.; Tani, Y.; Cartron, J.P.; Arnaud, L. (2012). "ABCB6 is Dispensable for Erythropoiesis and Specifies the New Blood Group System Langereis". Nature Genetics. 44 (2, January 15): 170–173. doi:10.1038/ng.1069. PMC3664204. PMID22246506. [Quoting Abstract: The human ATP-binding cassette (ABC) transporter ABCB6 has been described as a mitochondrial porphyrin transporter essential for heme biosynthesis, but it is also suspected to contribute to anticancer drug resistance, as do other ABC transporters located at the plasma membrane. We identified ABCB6 as the genetic basis of the Lan blood group antigen expressed on red blood cells but also at the plasma membrane of hepatocellular carcinoma (HCC) cells, and we established that ABCB6 encodes a new blood group system (Langereis, Lan). Targeted sequencing of ABCB6 in 12 unrelated individuals of the Lan(-) blood type identified 10 different ABCB6 null mutations. This is the first report of deficient alleles of this human ABC transporter gene. Of note, Lan(-) (ABCB6(-/-)) individuals do not suffer any clinical consequences, although their deficiency in ABCB6 may place them at risk when determining drug dosage.]
^Mais, Daniel (2014). Quick compendium of clinical pathology. United States: American Society for Clinical Pathology Press. ISBN978-0-89189-615-9. OCLC895712380.
Dean, Laura (2005). Blood Groups and Red Cell Antigens. Bethesda, MD, USA: National Center for Biotechnology Information (NCBI), National Library of Medicine, National Institutes of Health. Retrieved 19 February 2016.
SIB-EBI-PIR (2016). "Blood group Antigen Proteins: List of Entries, 17 February version". Swiss-Prot Protein Knowledgebase. Geneva, CHE: Swiss Institute of Bioinformatic (SIB), in cooperation with the European Bioinformatics Institute (EBI, Hinxton, ENG), and the Protein Information Resource (PIR, Washington DC, USA). Retrieved 19 February 2016.
