The Mystery of Blood Typing: The Facts You Need to Know About Your Blood!

Описание: .

Chapters

0:00 Introduction
0:21 Why is blood typing done?
2:04 How is blood typing done?
2:27 Risks of blood typing?




A blood type (also known as a blood group) is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending 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.[1]

Blood types are inherited and represent contributions from both parents of an individual. As of September 2022, a total of 43 human blood group systems are recognized by the International Society of Blood Transfusion (ISBT).[2] The two most important blood group systems are ABO and Rh; they determine someone's blood type (A, B, AB, and O, with + or − denoting RhD status) for suitability in blood transfusion.
Blood group systems
Main article: Human blood group systems

A complete blood type would describe each of the 43 blood groups, and an individual's blood type is one of many possible combinations of blood-group antigens.[2] Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease.[3][4][5][6] Another more common cause of blood type change is a bone marrow transplant. Bone-marrow transplants are performed for many leukemias and lymphomas, among other diseases. If a person receives bone marrow from someone of a different ABO type (e.g., a type A patient receives a type O bone marrow), the patient's blood type should eventually become the donor's type, as the patient's hematopoietic stem cells (HSCs) are destroyed, either by ablation of the bone marrow or by the donor's T-cells. 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.[citation needed]

Some blood types are associated with inheritance of other diseases; for example, the Kell antigen is sometimes associated with McLeod syndrome.[7] Certain blood types may affect susceptibility to infections, an example being the resistance to specific malaria species seen in individuals lacking the Duffy antigen.[8] The Duffy antigen, presumably as a result of natural selection, is less common in population groups from areas having a high incidence of malaria.[9]
ABO blood group system
ABO blood group system: diagram showing the carbohydrate chains that determine the ABO blood group
Main article: ABO blood group system

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 A), those with antigen B (group B), those 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]

Antigen A with antibody B
Antigen B with antibody A
Antigen AB with neither antibody A nor B
Antigen null (group O) with both antibody A and B

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.[citation needed]