According to the International Society of Blood Transfusion (ISBT), there are 43 different types of blood group systems found in humans. Blood group can be defined as the system that consists of red blood cells along with a set of antigens whose specificity is controlled by specific genes.
The different types of systems that have been identified include the ABO system, Rhesus system, Lutheran system, Dombrock system, MNS system and many more. Let us discuss some of the types in brief.
The ABO Blood Group System
The ABO blood group system is based on the presence or absence of the antigens A and B on the surface of red blood cells. This system was introduced by Karl Landsteiner in 1901. This is the most common system of blood groups used to distinguish between the types of human blood.
According to this system, the blood cells having antigen A on their surface have antibodies against B in their serum which makes them a type A blood group. Similarly, humans having blood cells with antigen B possess antibodies against A and make them type B blood group. Type O blood group does not contain any antigen on their red blood cell surfaces but they do have antibodies against both A and B. Lastly, type AB have both the antigens A and B on their cell surfaces but no antibodies in their serum.
This system of blood grouping helps in easy transfusion of blood from one person to another. For your better understanding, below is a blood group system diagram in tabulated form.
The Rhesus System
The Rh blood blood group system is the second most used system after the ABO system for blood transfusions. It was first found in Rhesus monkeys. According to this system there are 49 blood group antigens present on the red blood cell surface. Out of the 49, five most important ones are C, D, E , c and e.
If a person possesses the Rh(D) antigen along with the antigen A, they are considered to be A+, however if the person does not have Rh(D) antigen but does have the antigen A, they are considered as A-.
The Dombrock Blood Group System
The Dombrock blood group system is based on the presence of two glycoproteins Doa and Dob and five antigens Gy(a), Hy, Jo(a), DOYA, and DOMR on the surface of red blood cells. According to a study, 65% of northern Europeans possess the Doa antigen and the majority of Africans and Asians were found to have Dob antigen.
The Lutheran Blood Group System
The Lutheran blood group system is based on the presence of Lutheran antigen on the surface of red blood cells. There are 19 antigens that are released as a variation in the BCAM gene. The Lutheran glycoproteins are members of the immunoglobulin superfamily and are majorly involved in the transport of matured red blood cells from bone marrow to the peripheral circulation.
The MNS Blood Group System
The MNS blood group system is based on two genes, glycophorin A and B on chromosome 4 that codes for about 50 antigens. The most important antigens in the system are M, N, S, s and U. It was discovered in 1927 by Landsteiner and his colleagues. The glycophorins A and B are important receptors for cytokines, viruses and bacteria.
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