A blood type also known as a blood group is a classification of bloodbased on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells RBCs. These antigens may be proteinscarbohydratesglycoproteinsor glycolipidsdepending on the blood group system.
Some of these antigens are also present on the surface of other types of cells of various tissues. Several of these red blood cell surface antigens can stem from one allele or an alternative version of a gene and collectively form a blood group system.
Blood types are inherited and represent contributions from both parents of an individual. A complete blood type would describe each of the 44 blood groups, and an individual's blood type is one of many possible combinations of blood-group antigens.
Bone-marrow transplants are performed for many leukemias and lymphomasamong other diseases. If a person receives bone marrow from someone of a different ABO type e. Once all the patient's original red blood cells have died, they will have been fully replaced by new cells derived from the donor HSCs.
Provided the donor had a different ABO type, the new cells' surface antigens will be different from those on the surface of the patient's original red blood cells. Some blood types are associated with inheritance of other diseases; for example, the Kell antigen is sometimes associated with McLeod syndrome.
The ABO blood group system involves two antigens and two antibodies found in human blood. The two antigens are antigen A and antigen B. The two antibodies are antibody A and antibody B. The antigens are present on the red blood cells and the antibodies in the serum.
Regarding the antigen property of the blood all human beings can be classified into four groups, those with antigen A group Athose with antigen B group Bthose with both antigen A and B group AB and those with neither antigen group O.
The antibodies present together with the antigens are found as follows: [ citation needed ]. There is an agglutination reaction between similar antigen and antibody for example, antigen A agglutinates the antibody A and antigen B agglutinates the antibody B.
Thus, transfusion can be considered safe as long as the serum of the recipient does not contain antibodies for the blood cell antigens of the donor. The ABO system is the most important blood-group system in human-blood transfusion. The associated anti-A and anti-B antibodies are usually immunoglobulin Mabbreviated IgMantibodies.
It has been hypothesized that ABO IgM antibodies are produced in the first years of life by sensitization to environmental substances such as food, bacteriaand virusesalthough blood group compatibility rules are applied to newborn and infants as a matter of practice.
The Rh system Rh meaning Rhesus is the second most significant blood-group system blodgrupp b positiv gravid human-blood transfusion with currently 50 antigens. The most significant Rh antigen is the D antigen, because it is the most likely to provoke an immune system response of the five main Rh antigens.
It is common for D-negative individuals not to have any anti-D IgG or IgM antibodies, because anti-D antibodies are not usually produced by sensitization against environmental substances. However, D-negative individuals can produce IgG anti-D antibodies following a sensitizing event: possibly a fetomaternal transfusion of blood from a fetus in pregnancy or occasionally a blood transfusion with D positive RBCs.