Blood type

Blood type

Overview

A blood type is a classification of blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 based on the presence or absence of inherited
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

 antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

ic substances on the surface of red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...

s (RBCs). These antigens may be protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

s, glycoprotein
Glycoprotein
Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...

s, or glycolipid
Glycolipid
Glycolipids are lipids with a carbohydrate attached. Their role is to provide energy and also serve as markers for cellular recognition.-Metabolism:...

s, depending on the blood group system. Some of these antigens are also present on the surface of other types of cells of various tissues
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

. Several of these red blood cell surface antigens can stem from one allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...

 (or very closely linked gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

s) and collectively form a blood group system.
Blood types are inherited and represent contributions from both parents.
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Encyclopedia

A blood type is a classification of blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 based on the presence or absence of inherited
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

 antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

ic substances on the surface of red blood cell
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...

s (RBCs). These antigens may be protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...

s, glycoprotein
Glycoprotein
Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...

s, or glycolipid
Glycolipid
Glycolipids are lipids with a carbohydrate attached. Their role is to provide energy and also serve as markers for cellular recognition.-Metabolism:...

s, depending on the blood group system. Some of these antigens are also present on the surface of other types of cells of various tissues
Tissue (biology)
Tissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...

. Several of these red blood cell surface antigens can stem from one allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...

 (or very closely linked gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

s) and collectively form a blood group system.
Blood types are inherited and represent contributions from both parents. A total of 30 human blood group systems
Human blood group systems
The International Society of Blood Transfusion currently recognises 30 major blood group systems . Thus, in addition to the ABO antigens and Rhesus antigens, many other antigens are expressed on the red blood cell surface membrane...

 are now recognized by the International Society of Blood Transfusion
International Society of Blood Transfusion
The International Society of Blood Transfusion , is a scientific society, founded in 1935, which aims to promote the study of blood transfusion, and to spread the know-how about the manner in which blood transfusion medicine and science best can serve the patient's interests. The society's central...

 (ISBT).

Many pregnant
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

 women carry a fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

 with a blood type different from their own, and the mother can form antibodies against fetal RBCs. Sometimes these maternal antibodies are IgG
Immunoglobulin G
Immunoglobulin G are antibody molecules. Each IgG is composed of four peptide chains — two heavy chains γ and two light chains. Each IgG has two antigen binding sites. Other immunoglobulins may be described in terms of polymers with the IgG structure considered the monomer.IgG constitutes 75%...

, a small immunoglobulin, which can cross the placenta and cause hemolysis
Hemolysis
Hemolysis —from the Greek meaning "blood" and meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes and the release of their contents into surrounding fluid...

 of fetal RBCs, which in turn can lead to hemolytic disease of the newborn
Hemolytic disease of the newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta...

, an illness of low fetal blood counts
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

 that ranges from mild to severe.

Blood group systems


A complete blood type would describe a full set of 30 substances on the surface of RBCs, and an individual's blood type is one of the many possible combinations of blood-group antigens. Across the 30 blood groups, over 600 different blood-group antigens have been found, but many of these are very rare, some being found mainly in certain ethnic groups.

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
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...

, malignancy, or autoimmune disease
Autoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...

. Another more common cause in blood type change is a bone marrow transplant
Bone marrow transplant
Hematopoietic stem cell transplantation is the transplantation of multipotent hematopoietic stem cell or blood, usually derived from bone marrow, peripheral blood stem cells, or umbilical cord blood...

. Bone-marrow transplants are performed for many leukemias and lymphomas, among other diseases. If a person receives bone marrow from someone who is a different ABO type (e.g., a type A patient receives a type O bone marrow), the patient's blood type will eventually convert to the donor's type.

Some blood types are associated with inheritance of other diseases; for example, the Kell antigen is sometimes associated with McLeod syndrome
McLeod syndrome
McLeod syndrome is a genetic disorder that may affect the blood, brain, peripheral nerves, muscle and heart. It is caused by a variety of recessively-inherited mutations in the XK gene on the X chromosome...

. Certain blood types may affect susceptibility to infections, an example being the resistance to specific malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...

 species seen in individuals lacking the Duffy antigen
Duffy antigen
Duffy antigen/chemokine receptor also known as Fy glycoprotein or CD234 is a protein that in humans is encoded by the DARC gene....

. The Duffy antigen, presumably as a result of natural selection
Natural selection
Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....

, is less common in ethnic groups from areas with a high incidence of malaria.

ABO blood group system



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 M
Immunoglobulin M
Immunoglobulin M, or IgM for short, is a basic antibody that is produced by B cells. It is the primary antibody against A and B antigens on red blood cells. IgM is by far the physically largest antibody in the human circulatory system...

, abbreviated IgM
IGM
IGM as an acronym or abbreviation can refer to:* Immunoglobulin M , the primary antibody against A and B antigens on red blood cells* International Grandmaster, a chess ranking* intergalactic medium* Intragroup medium - see: Intracluster medium...

, antibodies. ABO IgM antibodies are produced in the first years of life by sensitization to environmental substances such as food, bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

, and virus
Virus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

es. The O in ABO is often called 0 (zero, or null) in other languages.
Phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

Genotype
Genotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...

A AA or AO
B BB or BO
AB AB
O OO

Rh blood group system



The Rh system is the second most significant blood-group system in 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 RBC
Red blood cell
Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...

s. Rh disease
Rh disease
Rh disease is one of the causes of hemolytic disease of the newborn...

 can develop in these cases. Rh negative blood types are much less in proportion of Asian populations (0.3%) than they are in White (15%).
In the table below, the presence or absence of the Rh antigens is signified by the + or - sign, so that for example the A- group does not have any of the Rh antigens.

ABO and Rh distribution by country

ABO and Rh blood type distribution by nation (population averages)
Country Population  O+  A+  B+ AB+  O-  A-  B- AB-
Australia 21,000,000 40% 31% 5% 2% 9% 7% 2% 1%
Austria 8,210,281 30% 33% 12% 6% 7% 8% 3% 1%
Belgium 10,414,336 38% 34% 8.5% 4.1% 7% 6% 1.5% 0.8%
Brazil 198,739,269 36% 34% 8% 2.5% 9% 8% 2% 0.5%
Canada 33,487,208 39% 36% 7.6% 2.5% 7% 6% 1.4% 0.5%
Denmark 5,500,510 35% 37% 8% 4% 6% 7% 2% 1%
Estonia 1,299,371 30% 31% 20% 6% 4.5% 4.5% 3% 1%
Finland 5,250,275 27% 38% 15% 7% 4% 6% 2% 1%
France 62,150,775 36% 37% 9% 3% 6% 7% 1% 1%
Germany 82,329,758 35% 37% 9% 4% 6% 6% 2% 1%
Hong Kong 7,055,071 40% 26% 27% 7% 0.31% 0.19% 0.14% 0.05%
Hungary 10,198,315 31% 38% 18.8% 12.2%
Iceland 306,694 47.6% 26.4% 9.3% 1.6% 8.4% 4.6% 1.7% 0.4%
India 1,166,079,217 36.5% 22.1% 30.9% 6.4% 2.0% 0.8% 1.1% 0.2%
Ireland 4,203,200 47% 26% 9% 2% 8% 5% 2% 1%
Israel 7,233,701 32% 34% 17% 7% 3% 4% 2% 1%
Netherlands 16,715,999 39.5% 35% 6.7% 2.5% 7.5% 7% 1.3% 0.5%
New Zealand 4,213,418 38% 32% 9% 3% 9% 6% 2% 1%
Norway 4,660,539 34% 40.8% 6.8% 3.4% 6% 7.2% 1.2% 0.6%
Poland 38,482,919 31% 32% 15% 7% 6% 6% 2% 1%
Portugal 10,707,924 36.2% 39.8% 6.6% 2.9% 6.0% 6.6% 1.1% 0.5%
Saudi Arabia 28,686,633 48% 24% 17% 4% 4% 2% 1% 0.23%
South Africa 49,320,000 39% 32% 12% 3% 7% 5% 2% 1%
Spain 48,125,002 36% 34% 8% 2.5% 9% 8% 2% 0.5%
Sweden 9,433,875 32% 37% 10% 5% 6% 7% 2% 1%
Taiwan 24,000,000 43.9% 25.9% 23.9% 6.0% 0.1% 0.1% 0.01% 0.02%
Turkey 76,805,524 22.8% 30.8% 14.2% 7.2% 3.7% 4.8% 1.6% 0.8%
United Kingdom 61,113,205 37% 35% 8% 3% 7% 7% 2% 1%
Ukraine 45,706,120 ~40% ~10%
United States 307,212,123 37.4% 35.7% 8.5% 3.4% 6.6% 6.3% 1.5% 0.6%
Population-weighted mean
Weighted mean
The weighted mean is similar to an arithmetic mean , where instead of each of the data points contributing equally to the final average, some data points contribute more than others...

 
(total population = 2,261,025,244) 36.44% 28.27% 20.59% 5.06% 4.33% 3.52% 1.39% 0.45%


{| class="wikitable collapsible collapsed"
! Racial and ethnic distribution of ABO (without Rh) blood types
(This table has more entries than the table above but does not distinguish between Rh types.)
|-
|
{| class="wikitable sortable"
|-
! width=200 | People group
! width=70 | O (%)
! width=70 | A (%)
! width=70 | B (%)
! width=70 | AB (%)
|-

Aborigines
61
39
0
0



Abyssinians
43
27
25
5


Ainu (Japan)
17
32

32
18


Albanians
38

43
13
6


Grand Andamanese
9
60
23
9



Arabs
34
31
29
6



Armenians
31
50
13
6


Asian (in USA—general)
40
28
27
5


Austrians
36
44
13
6


Bantus
46
30
19
5


Basques
51
44
4
1


Belgians
47
42
8
3


Blackfoot (N. Am. Indian)
17
82
0
1




Bororo (Brazil)
100
0
0
0



Brazilians
47
41
9
3



Bulgarians
32
44
15
8


Burmese
36
24

33
7



Buryats (Siberia)
33

21
38
8



Bushmen

56
34
9
2


Chinese-Canton

46
23
25
6



Chinese-Peking

29
27
32
13



Chuvash

30
29
33
7



Czechs

30
44
18
9


Danes

41
44
11
4



Dutch

45
43
9
3


Egyptians

33
36
24
8



English

47
42
9
3



Eskimos (Alaska)

38
44
13
5



Eskimos (Greenland)

54
36
23
8



Estonians

34
36
23
8


Fijians

44
34
17
6



Finns

34
41
18
7



French

43
47
7
3


Georgians

46
37
12
4



Germans

41
43
11
5



Greeks

40
42
14
5



Gypsies (Hungary)

29
27
35
10


Hawaiians

37

61
2
1




Hindus (Bombay)
32
29
28
11




Hungarians
36
43
16
5



Icelanders
56
32
10

3



Indians (India—general)
37
22

33
7



Indians (USA—general)
79

16
4
1



Irish

52
35
10
3



Italians (Milan)

46
41
11
3


Japanese

30
38
22
10



Jews (Germany)

42
41
12
5



Jews (Poland)

33
41
18
8


Kalmuks

26
23
41
11



Kikuyu (Kenya)

60
19
20
1




Koreans
28
32
31
10



Lapps
29
63
4

4



Latvians
32
37

24
7



Lithuanians
40

34
20
6



Malaysians

62
18
20
0


Maori

46
54
1
0



Mayas

98
1
1
1



Moros

64
16
20
0


Navajo (N. Am. Indian)

73
27
0
0



Nicobarese (Nicobars) 

74
9
15
1



Norwegians

39
50
8
4


Papuas (New Guinea)

41
27
23
9



Persians

38
33
22
7



Peru (Indians)

100
0
0
0



Filipinos

45
22
27
6



Poles

33
39
20
9



Portuguese

35
53
8
4


Romanians

34
41
19
6



Russians

33
36
23
8


Sardinians

50
26
19
5



Scots

51
34
12
3



Serbians

38
42
16
5



Shompen (Nicobars)

100
0
0
0



Slovaks

42
37
16
5



South Africans

45
40
11
4



Spanish

38
47
10
5



Sudanese

62
16
21
0



Swedes

38
47
10
5



Swiss

40
50
7
3


Tatars

28
30
29
13



Thais

37
22
33
8



Turks

43
34
18
6


Ukrainians

37
40
18
6


USA (US blacks)

49
27
20
4


USA (US whites)

45
40
11
4


Vietnamese
42
22
30
5





Mean
43.91
34.80
16.55
5.14



Standard deviation
16.87
13.80
9.97
3.41



|}

Blood group B has its highest frequency in Northern India and neighboring Central Asia, and its incidence diminishes both towards the west and the east, falling to single digit percentages in Spain. It is believed to have been entirely absent from Native American and Australian Aboriginal populations prior to the arrival of Europeans in those areas.

Blood group A is associated with high frequencies in Europe, especially in Scandinavia and Central Europe, although its highest frequencies occur in some Australian Aborigine populations and the Blackfoot Indians of Montana.

Other blood group systems



The International Society of Blood Transfusion
International Society of Blood Transfusion
The International Society of Blood Transfusion , is a scientific society, founded in 1935, which aims to promote the study of blood transfusion, and to spread the know-how about the manner in which blood transfusion medicine and science best can serve the patient's interests. The society's central...

 currently recognizes 30 blood-group systems (including the ABO and Rh systems). Thus, in addition to the ABO antigens and Rh antigens, many other antigens are expressed on the RBC surface membrane. For example, an individual can be AB, D positive, and at the same time M and N positive (MNS system
MNS antigen system
The MNS antigen system is a human blood group system based upon two genes on chromosome 4. There are currently 46 antigens in the system, but the five most important are called M, N, S, s, and U....

), K positive (Kell system
Kell antigen system
The Kell antigen system is a group of antigens on the human red blood cell surface which are important determinants of blood type and are targets for autoimmune or alloimmune diseases which destroy red blood cells. Kell can be noted as K, k, or Kp...

), Lea or Leb negative (Lewis system
Lewis antigen system
The Lewis antigen system is a human blood group system based upon genes on chromosome 19 q13.3, and 19p13.3 , which both have fucosyltransferase activity. There are two main types of Lewis antigens, Lewis a and Lewis b. They are red cell antigens which are not produced by the erythrocyte itself...

), and so on, being positive or negative for each blood group system antigen. Many of the blood group systems were named after the patients in whom the corresponding antibodies were initially encountered.

Blood transfusion



Transfusion medicine is a specialized branch of hematology
Hematology
Hematology, also spelled haematology , is the branch of biology physiology, internal medicine, pathology, clinical laboratory work, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases...

 that is concerned with the study of blood groups, along with the work of a blood bank
Blood bank
A blood bank is a cache or bank of blood or blood components, gathered as a result of blood donation, stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a division of a hospital laboratory where the storage of blood product occurs and where proper...

 to provide a transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

 service for blood and other blood products. Across the world, blood products must be prescribed by a medical doctor (licensed physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 or surgeon
Surgeon
In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...

) in a similar way as medicines.

Much of the routine work of a blood bank
Blood bank
A blood bank is a cache or bank of blood or blood components, gathered as a result of blood donation, stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a division of a hospital laboratory where the storage of blood product occurs and where proper...

 involves testing blood from both donors and recipients to ensure that every individual recipient is given blood that is compatible and is as safe as possible. If a unit of incompatible blood is transfused
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

 between a donor
Blood donation
A blood donation occurs when a person voluntarily has blood drawn and used for transfusions or made into medications by a process called fractionation....

 and recipient, a severe acute hemolytic reaction with hemolysis
Hemolysis
Hemolysis —from the Greek meaning "blood" and meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes and the release of their contents into surrounding fluid...

 (RBC destruction), renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...

 and shock is likely to occur, and death is a possibility. Antibodies can be highly active and can attack RBCs and bind components of the complement system
Complement system
The complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the immune system called the innate immune system that is not adaptable and does not change over the course of an individual's lifetime...

 to cause massive hemolysis of the transfused blood.

Patients should ideally receive their own blood or type-specific blood products to minimize the chance of a transfusion reaction. Risks can be further reduced by cross-matching
Cross-matching
Cross-matching blood, in transfusion medicine, refers to the complex testing that is performed prior to a blood transfusion, to determine if the donor's blood is compatible with the blood of an intended recipient, or to identify matches for organ transplants. Cross-matching is usually performed...

 blood, but this may be skipped when blood is required for an emergency. Cross-matching involves mixing a sample of the recipient's serum with a sample of the donor's red blood cells and checking if the mixture agglutinates, or forms clumps. If agglutination is not obvious by direct vision, blood bank technicians usually check for agglutination
Agglutination (biology)
Agglutination is the clumping of particles. The word agglutination comes from the Latin agglutinare, meaning "to glue."This occurs in biology in three main examples:...

 with a microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

. If agglutination occurs, that particular donor's blood cannot be transfused to that particular recipient. In a blood bank it is vital that all blood specimens are correctly identified, so labeling has been standardized using a barcode
Barcode
A barcode is an optical machine-readable representation of data, which shows data about the object to which it attaches. Originally barcodes represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or 1 dimensional . Later they evolved into rectangles,...

 system known as ISBT 128
ISBT 128
ISBT 128 is a system for identification, labeling and processing of human blood, tissue, and cellular therapy products using an internationally standardized system. The acronym ISBT stands for the International Society of Blood Transfusion...

.

The blood group may be included on identification tags
Dog tag (identifier)
A dog tag is the informal name for the identification tags worn by military personnel, named such as it bears resemblance to actual dog tags. The tag is primarily used for the identification of dead and wounded and essential basic medical information for the treatment of the latter, such as blood...

 or on tattoo
Tattoo
A tattoo is made by inserting indelible ink into the dermis layer of the skin to change the pigment. Tattoos on humans are a type of body modification, and tattoos on other animals are most commonly used for identification purposes...

s worn by military personnel, in case they should need an emergency blood transfusion. Frontline German Waffen-SS had blood group tattoos
SS blood group tattoo
SS blood group tattoos were worn by members of the Waffen-SS in Nazi Germany during World War II to identify the individual's blood type. After the war, the tattoo was taken to be prima facie, if not perfect, evidence of being part of the Waffen-SS, leading to potential arrest and...

 during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

.

Rare blood types can cause supply problems for blood bank
Blood bank
A blood bank is a cache or bank of blood or blood components, gathered as a result of blood donation, stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a division of a hospital laboratory where the storage of blood product occurs and where proper...

s and hospitals. For example Duffy
Duffy antigen
Duffy antigen/chemokine receptor also known as Fy glycoprotein or CD234 is a protein that in humans is encoded by the DARC gene....

-negative blood occurs much more frequently in people of African origin, and the rarity of this blood type in the rest of the population can result in a shortage of Duffy-negative blood for these patients. Similarly for RhD negative people, there is a risk associated with travelling to parts of the world where supplies of RhD negative blood are rare, particularly East Asia
East Asia
East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...

, where blood services may endeavor to encourage Westerners to donate blood.

Hemolytic disease of the newborn (HDN)



A pregnant woman can make IgG blood group antibodies if her fetus has a blood group antigen that she does not have. This can happen if some of the fetus' blood cells pass into the mother's blood circulation (e.g. a small fetomaternal hemorrhage
Bleeding
Bleeding, technically known as hemorrhaging or haemorrhaging is the loss of blood or blood escape from the circulatory system...

 at the time of childbirth or obstetric intervention), or sometimes after a therapeutic blood transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

. This can cause Rh disease
Rh disease
Rh disease is one of the causes of hemolytic disease of the newborn...

 or other forms of hemolytic disease of the newborn
Hemolytic disease of the newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta...

 (HDN) in the current pregnancy and/or subsequent pregnancies. If a pregnant woman is known to have anti-D antibodies, the Rh blood type of a fetus
Fetus
A fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth.In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age, which is the 9th week after fertilization.-Etymology and spelling variations:The...

 can be tested by analysis of fetal DNA in maternal plasma to assess the risk to the fetus of Rh disease. One of the major advances of twentieth century medicine was to prevent this disease by stopping the formation of Anti-D antibodies by D negative mothers with an injectable medication called Rho(D) immune globulin
Rho(D) Immune Globulin
Rho Immune Globulin is a medicine given by intramuscular injection that is used to prevent the immunological condition known as Rhesus disease...

. Antibodies associated with some blood groups can cause severe HDN, others can only cause mild HDN and others are not known to cause HDN.

Blood products


To provide maximum benefit from each blood donation and to extend shelf-life, blood bank
Blood bank
A blood bank is a cache or bank of blood or blood components, gathered as a result of blood donation, stored and preserved for later use in blood transfusion. The term "blood bank" typically refers to a division of a hospital laboratory where the storage of blood product occurs and where proper...

s fractionate
Fractionation
See also: Fractionated spacecraftFractionation is a separation process in which a certain quantity of a mixture is divided up in a number of smaller quantities in which the composition changes according to a gradient. Fractions are collected based on differences in a specific property of the...

 some whole blood into several products. The most common of these products are packed RBCs, plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...

, platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes.  The average lifespan of a platelet is normally just 5 to 9 days...

s, cryoprecipitate
Cryoprecipitate
Cryoprecipitate, also called "Cryoprecipitated Antihemophilic Factor", "Cryoprecipitated AHF", and most commonly just "cryo", is a frozen blood product prepared from plasma.It is often transfused as a four to six unit pool instead of as a single product...

, and fresh frozen plasma (FFP). FFP is quick-frozen to retain the labile clotting factors V
Factor V
Factor V is a protein of the coagulation system, rarely referred to as proaccelerin or labile factor. In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor...

 and VIII
Factor VIII
Factor VIII is an essential blood clotting factor also known as anti-hemophilic factor . In humans, Factor VIII is encoded by the F8 gene...

, which are usually administered to patients who have a potentially fatal clotting problem caused by a condition such as advanced liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...

 disease, overdose of anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...

, or disseminated intravascular coagulation
Disseminated intravascular coagulation
Disseminated intravascular coagulation , also known as disseminated intravascular coagulopathy or consumptive coagulopathy, is a pathological activation of coagulation mechanisms that happens in response to a variety of diseases. DIC leads to the formation of small blood clots inside the blood...

 (DIC).

Units of packed red cells are made by removing as much of the plasma as possible from whole blood units.

Clotting factors synthesized by modern recombinant
Recombinant DNA
Recombinant DNA molecules are DNA sequences that result from the use of laboratory methods to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms...

 methods are now in routine clinical use for hemophilia, as the risks of infection transmission that occur with pooled blood products are avoided.

Red blood cell compatibility

  • Blood group AB individuals have both A and B antigens on the surface of their RBCs, and their blood plasma
    Blood plasma
    Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...

     does not contain any antibodies against either A or B antigen. Therefore, an individual with type AB blood can receive blood from any group (with AB being preferable), but can donate blood only to another type AB individual.
  • Blood group A individuals have the A antigen on the surface of their RBCs, and blood serum containing IgM
    IGM
    IGM as an acronym or abbreviation can refer to:* Immunoglobulin M , the primary antibody against A and B antigens on red blood cells* International Grandmaster, a chess ranking* intergalactic medium* Intragroup medium - see: Intracluster medium...

     antibodies against the B antigen. Therefore, a group A individual can receive blood only from individuals of groups A or O (with A being preferable), and can donate blood to individuals with type A or AB.
  • Blood group B individuals have the B antigen on the surface of their RBCs, and blood serum containing IgM antibodies against the A antigen. Therefore, a group B individual can receive blood only from individuals of groups B or O (with B being preferable), and can donate blood to individuals with type B or AB.
  • Blood group O (or blood group zero in some countries) individuals do not have either A or B antigens on the surface of their RBCs, but their blood serum contains IgM anti-A and anti-B antibodies against the A and B blood group antigens. Therefore, a group O individual can receive blood only from a group O individual, but can donate blood to individuals of any ABO blood group (i.e., A, B, O or AB). If a patient in a hospital situation were to need a blood transfusion in an emergency, and if the time taken to process the recipient's blood would cause a detrimental delay, O Negative blood can be issued.



{| class="wikitable" style="text-align:center;"
|+ Red blood cell compatibility table
|-
! rowspan="2" | Recipient[1]
! colspan="8" | Donor[1]
|-
! O−
! O+
! A−
! A+
! B−
! B+
! AB−
! AB+
|-
! O−
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
| style="width:3em" |
|-
! O+
|
|
|
|
|
|
|
|
|-
! A−
|
|
|
|
|
|
|
|
|-
! A+
|
|
|
|
|
|
|
|
|-
! B−
|
|
|
|
|
|
|
|
|-
! B+
|
|
|
|
|
|
|
|
|-
! AB−
|
|
|
|
|
|
|
|
|-
! AB+
|
|
|
|
|
|
|
|
|}

Table note

1. Assumes absence of atypical antibodies that would cause an incompatibility between donor and recipient blood, as is usual for blood selected by cross matching.


An Rh D-negative patient who does not have any anti-D antibodies (never being previously sensitized to D-positive RBCs) can receive a transfusion of D-positive blood once, but this would cause sensitization to the D antigen, and a female patient would become at risk for hemolytic disease of the newborn
Hemolytic disease of the newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta...

. If a D-negative patient has developed anti-D antibodies, a subsequent exposure to D-positive blood would lead to a potentially dangerous transfusion reaction. Rh D-positive blood should never be given to D-negative women of child bearing age or to patients with D antibodies, so blood banks must conserve Rh-negative blood for these patients. In extreme circumstances, such as for a major bleed when stocks of D-negative blood units are very low at the blood bank, D-positive blood might be given to D-negative females above child-bearing age or to Rh-negative males, providing that they did not have anti-D antibodies, to conserve D-negative blood stock in the blood bank. The converse is not true; Rh D-positive patients do not react to D negative blood.

This same matching is done for other antigens of the Rh system as C, c, E and e and for other blood group systems with a known risk for immunization such as the Kell system in particular for females of child-bearing age or patients with known need for many transfusions.

Plasma compatibility



Recipients can receive plasma of the same blood group, but otherwise the donor-recipient compatibility for blood plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...

 is the converse of that of RBCs: plasma extracted from type AB blood can be transfused to individuals of any blood group; individuals of blood group O can receive plasma from any blood group; and type O plasma can be used only by type O recipients.

{| class="wikitable" style="text-align:center;"
|+ Plasma compatibility table
! rowspan=2 | Recipient
! colspan="4" | Donor[1]
|-
! style="width:3em" | O
! style="width:3em" | A
! style="width:3em" | B
! style="width:3em" | AB
|-
! O
|
|
|
|
|-
! A
|
|
|
|
|-
! B
|
|
|
|
|-
! AB
|
|
|
|
|}


Table note

1. Assumes absence of strong atypical antibodies in donor plasma


Rh D antibodies are uncommon, so generally neither D negative nor D positive blood contain anti-D antibodies. If a potential donor is found to have anti-D antibodies or any strong atypical blood group antibody by antibody screening in the blood bank, they would not be accepted as a donor (or in some blood banks the blood would be drawn but the product would need to be appropriately labeled); therefore, donor blood plasma issued by a blood bank can be selected to be free of D antibodies and free of other atypical antibodies, and such donor plasma issued from a blood bank would be suitable for a recipient who may be D positive or D negative, as long as blood plasma and the recipient are ABO compatible...

Universal donors and universal recipients


With regard to transfusions of packed red blood cells, individuals with type O Rh D negative blood are often called universal donors, and those with type AB Rh D positive blood are called universal recipients; however, these terms are only generally true with respect to possible reactions of the recipient's anti-A and anti-B antibodies to transfused red blood cells, and also possible sensitization to Rh D antigens. One exception is individuals with hh antigen system
Hh antigen system
hh is a rare blood group also called Bombay Blood group. Individuals with the rare Bombay phenotype do not express H antigen...

 (also known as the Bombay phenotype) who can only receive blood safely from other hh donors, because they form antibodies against the H antigen present on all red blood cells.

Blood donors with particularly strong anti-A, anti-B or any atypical blood group antibody are excluded from blood donation. The possible reactions of anti-A and anti-B antibodies present in the transfused blood to the recipients RBCs need not be considered, because a relatively small volume of plasma containing antibodies is transfused.

By way of example: considering the transfusion of O Rh D negative blood (universal donor blood) into a recipient of blood group A Rh D positive, an immune reaction between the recipient's anti-B antibodies and the transfused RBCs is not anticipated. However, the relatively small amount of plasma in the transfused blood contains anti-A antibodies, which could react with the A antigens on the surface of the recipients RBCs, but a significant reaction is unlikely because of the dilution factors. Rh D sensitization is not anticipated.

Additionally, red blood cell surface antigens other than A, B and Rh D, might cause adverse reactions and sensitization, if they can bind to the corresponding antibodies to generate an immune response. Transfusions are further complicated because platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes.  The average lifespan of a platelet is normally just 5 to 9 days...

s and white blood cell
White blood cell
White blood cells, or leukocytes , are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five different and diverse types of leukocytes exist, but they are all produced and derived from a multipotent cell in the bone marrow known as a...

s (WBCs) have their own systems of surface antigens, and sensitization to platelet or WBC antigens can occur as a result of transfusion.

With regard to transfusions of plasma, this situation is reversed. Type O plasma, containing both anti-A and anti-B antibodies, can only be given to O recipients. The antibodies will attack the antigens on any other blood type. Conversely, AB plasma can be given to patients of any ABO blood group due to not containing any anti-A or anti-B antibodies.

Blood group genotyping


In addition to the current practice of serologic testing of blood types, the progress in molecular diagnostics allows the increasing use of blood group genotyping. In contrast to serologic tests reporting a direct blood type phenotype, genotyping allows the prediction of a phenotype based on the knowledge of the molecular basis of the currently known antigens. This allows a more detailed determination of the blood type and therefore a better match for transfusion, which can be crucial in particular for patients with needs for many transfusions to prevent allo-immunization.

History


The two most significant blood group systems were discovered by Karl Landsteiner
Karl Landsteiner
Karl Landsteiner , was an Austrian-born American biologist and physician of Jewish origin. He is noted for having first distinguished the main blood groups in 1900, having developed the modern system of classification of blood groups from his identification of the presence of agglutinins in the...

 during early experiments with blood transfusion: the ABO group
ABO blood group system
The ABO blood group system is the most important blood type system in human blood transfusion. The associated anti-A antibodies and anti-B antibodies are usually IgM antibodies, which are usually produced in the first years of life by sensitization to environmental substances such as food,...

 in 1901 and in co-operation with Alexander S. Wiener
Alexander S. Wiener
Alexander Solomon Wiener , a lifelong resident of New York City, was recognized internationally for his contributions to medicine. He was an outstanding leader in the fields of forensic medicine, serology, and immunogenetics. His pioneer work led to discovery of the Rh factor in 1937, along with Dr...

 the Rhesus group
Rhesus blood group system
The Rh blood group system is one of thirty current human blood group systems. Clinically, it is the most important blood group system after ABO. At Present, the Rh blood group system consists of 50 defined blood-group antigens, among which the 5 antigens D, C, c, E, and e are the most important...

 in 1937. Development of the Coombs test
Coombs test
Coombs test refers to two clinical blood tests used in immunohematology and immunology...

 in 1945,
the advent of transfusion medicine
Transfusion medicine
Transfusion medicine is the branch of medicine that is concerned with the transfusion of blood and blood components. The blood bank is the section of the clinical laboratory where medical technologists process and distribute blood products under the supervision of a medical director, often...

, and the understanding of hemolytic disease of the newborn
Hemolytic disease of the newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis fetalis, is an alloimmune condition that develops in a fetus, when the IgG molecules produced by the mother pass through the placenta...

 led to discovery of more blood groups, and now 30 human blood group systems
Human blood group systems
The International Society of Blood Transfusion currently recognises 30 major blood group systems . Thus, in addition to the ABO antigens and Rhesus antigens, many other antigens are expressed on the red blood cell surface membrane...

 are recognized by the International Society of Blood Transfusion
International Society of Blood Transfusion
The International Society of Blood Transfusion , is a scientific society, founded in 1935, which aims to promote the study of blood transfusion, and to spread the know-how about the manner in which blood transfusion medicine and science best can serve the patient's interests. The society's central...

 (ISBT), and across the 30 blood groups, over 600 different blood group antigens have been found; many of these are very rare or are mainly found in certain ethnic groups. Blood types have been used in forensic science and were formerly used to demonstrate impossibility of paternity (e.g., a type AB man cannot be the father of a type O infant), but both of these uses are being replaced by genetic fingerprinting
Genetic fingerprinting
DNA profiling is a technique employed by forensic scientists to assist in the identification of individuals by their respective DNA profiles. DNA profiles are encrypted sets of numbers that reflect a person's DNA makeup, which can also be used as the person's identifier...

, which provides greater certainty.

Society and culture


A popular belief in Japan is that a person's ABO blood type is predictive of their personality
Personality psychology
Personality psychology is a branch of psychology that studies personality and individual differences. Its areas of focus include:* Constructing a coherent picture of the individual and his or her major psychological processes...

, character
Moral character
Moral character or character is an evaluation of a particular individual's durable moral qualities. The concept of character can imply a variety of attributes including the existence or lack of virtues such as integrity, courage, fortitude, honesty, and loyalty, or of good behaviors or habits...

, and compatibility with others
Interpersonal compatibility
Interpersonal compatibility is a concept that describes the long-term interaction between two or more individuals in terms of the ease and comfort of communication.-Existing concepts:...

. This belief is also widespread elsewhere in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

, notably Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...

. Deriving from ideas of historical scientific racism
Scientific racism
Scientific racism is the use of scientific techniques and hypotheses to sanction the belief in racial superiority or racism.This is not the same as using scientific findings and the scientific method to investigate differences among the humans and argue that there are races...

, the theory reached Japan in a 1927 psychologist's report, and the militarist government of the time commissioned a study aimed at breeding better soldiers. The fad faded in the 1930s because of its unscientific basis . The theory has long since been rejected by scientists, but it was revived in the 1970s by Masahiko Nomi
Masahiko Nomi
Masahiko Nomi was a Japanese journalist who advocated Takeji Furukawa's idea of an influence of blood type on personality. He was also known as a sumo essayist....

, a broadcaster who had no medical background.

Further reading

  • Mollison PL, Engelfriet CP and Contreras M. Blood Transfusion in Clinical Medicine. 1997. 10th edition. Blackwell Science, Oxford, UK. ISBN 0-86542-881-6.

External links

  • BGMUT Blood Group Antigen Gene Mutation Database at NCBI
    National Center for Biotechnology Information
    The National Center for Biotechnology Information is part of the United States National Library of Medicine , a branch of the National Institutes of Health. The NCBI is located in Bethesda, Maryland and was founded in 1988 through legislation sponsored by Senator Claude Pepper...

    , NIH has details of genes and proteins, and variations thereof, that are responsible for blood types (ABO) (Rhesus D)
  • Blood Type Calculator – The calculator is used to determine the blood type of child when the blood type of parents are known.
  • Blood types – intuitive explanation using Venn diagram
    Venn diagram
    Venn diagrams or set diagrams are diagrams that show all possible logical relations between a finite collection of sets . Venn diagrams were conceived around 1880 by John Venn...

    s