ဂကူဆီ

right|thumb|435x435px|ဂကူဆီ (ဟွံသေင်မ္ဂး ဂကောံဆီ) မပါ်လဝ် နကဵု ပိဂကောံ ABO မဒှ်အန္တိဂေန်  (antigen) မနွံ ပ္ဍဲကလာပ်ဆီဗကေတ်။
ဂကူဆီ (သီုမကော်စ ဂကောံဆီ) ဂှ် ပါ်လဝ် နကဵု မဒုင်သဇိုင် ကု မနွံကု ကေုာံ မသက်ကု ဓါတ်အန္တိဗောဒဳ (antibodies) ကေုာံ အာဲကၟာဲ အန္တိဂေန်  (inherited antigen) ပ္ဍဲဗလးမုက်ကလာပ်ရုပ်မဆီဗကေတ်ရ။ ဓါတ်အန္တိဂေန်တအ်ဂှ် ဗွဲမဗဗွဲ ကုဂကောံဆီဂမၠိုင်တုဲ ဒှ်ဓါတ်ပြောတိန်ဂမၠိုင် (proteins)၊ ဓါတ်ကာဗောဟိဒြိဒ်ဂမၠိုင် (carbohydrates)၊ ဓါတ်ဂၠုကောပြောတိန်ဂမၠိုင် (glycoproteins) ဟွံသေင်မ္ဂး ဓါတ်ဂၠုကောလိပိဒ်ဂမၠိုင် (glycolipids) မွဲမွဲသာ်အိုတ်ရ။ ဓါတ်အန္တိဂေန်လ္ၚဵုတအ်ဂှ် ပ္ဍဲဗလးမုက် ကလာပ်ရုပ်တၞဟ် ပ္ဍဲကဵုတိဿူဂမၠိုင် (tissues)လေဝ် ဂွံဆဵုကေတ်ကီုရ။ အန္တိဂေန် မဂွံဆဵုကေတ် ပ္ဍဲဗလးမုက်  ကလာပ်ရုပ်ဆီဗကေတ်ဗွဲမဂၠိုင်တအ်ဂှ် စေန်ဆက်ကၠုင် နူတမ်မူလဗဳဇ ကေုာံ မပံင်နှဴတုဲ ကတဵုဗဒှ်ပတိုန် သၞောတ်ဂကောံဆီမွဲရ။

ဂကူဆီဂှ် ဒှ်အာဲကၟာဲ ကေုာံ မပါကၠုင် နူကဵု အံက်ၜါလပါ်။ စဵုကဵုသၞာံ ၂၀၁၉ ဂှ် နကဵု ဂကောံစၠောအ်ဆီဂၠးကဝ် (International Society of Blood Transfusion - ISBT) စၟတ်သမ္တီလဝ် သၞောတ်ဂကောံဆီ ကောန်မၞိဟ် သီုဖအိုတ် နွံ ၃၈ သၞောတ်။ ပၞောဝ်တအ်ဂှ် သၞောတ်ကိစ္စဇၞော်အိုတ်ၜါသၞောတ်ဂှ် သၞောတ် ABO ကဵု Rh မဒှ်တုဲ နကဵုသၞောတ်ဏအ်မ္ဂး ပါ်လဝ် မၞိဟ်မွဲမွဲ ဒှ်ဂကူဆီ (A) ဟွံသေင်မ္ဂး (B) ဟွံသေင်မ္ဂး (AB) ဟွံသေင်မ္ဂး (O)၊ တုဲပၠန် လက်ကရဴဂှ် + (အပံင်)၊ ဟွံသေင်မ္ဂး − (အနုက်) ဟွံသေင်မ္ဂး 0 (သုည) နကဵုမစၟတ် RhD ရ။ ဂကူဆီဝွံ ဒှ်အရာ ကိစ္စဇၞော် ပ္ဍဲအခိင်ကာလ မစၠောအ်ပၠုပ်ဆီ၊ မဖနှဴဆီတအ်ရ။

## သၞောတ်ဂကောံဆီဂမၠိုင်
သၞောတ်လဒက်ပ္တန်ဆီမွဲ ပါ်လဝ် ဇၟာပ်ပ်ဂှ် နွံ ဂကောံဆီ သီုဖအိုတ် ၃၈ ဂကောံ၊ တုဲပၠန် ဇၟာပ်ဂကူဆီဂှ် ဒှ်ပၞောဝ်ကဵု ဂကောံဆီဂမၠိုင် မပံင်နှဴလဝ် နကဵု ဂကောံဆီအန္တိဂေန်ဂမၠိုင်ရ။ မၞိဟ်မွဲ နူကတဵုဒှ်မၞိဟ် ကလိဂွံလဝ် ဂကူဆီဂှ်မ္ဂး ကြပ်သီုဖအိုတ် ဒှ်ဂကူဆီဂှ် စဵုကဵု လအိတ်လမျီု ကီုလေဝ်၊ ဆဂး ဟိုတ်နူမပၠုပ်စုတ် ဓါတ်အန္တိဂေန်၊ ဟိုတ်နူယဲ မပလီုကဵု အန္တိဂေန်တုဲ ဂကူဆီ ပြံင်လှာဲအာတၞဟ် ကတဵုဒှ်မာန်ကီုရ။ ဆဂး အောန်ဗွဲမလောန်ရ။ ဟိုတ်ဂကူဆီ မဂွံပြံင်လှာဲမာန် အရာမကတဵုဒှ်စဂၠိုင်မွဲဂှ် ဟိုတ်နူယဲတုဲ ဒးသၠာဲထောအ် ကၠေင်ၜဝ်ဇုတ် (bone-marrow)ရ။ သမၠာဲကၠေင်ၜဝ်ဇုတ်မ္ဂး ဒးစကာ ဆီ (leukemias) ကေုာံ လုမ်ဖောမ် (lymphoma) ဗွဲမဂၠိုင်ရ။ ယဝ်ရ မၞိဟ်ယဲဂှ် ကလိဂွံ ကၠေင်ၜတ်ဇုတ် နူကဵု မၞိဟ်ဂကူဆီ ABO ဟွံတုပ် (ဥပမာ မၞိဟ်ယဲ ဂကူဆီ A ကလိဂွံ ကၠေင်ၜတ်ဇုတ် နူကဵု မၞိဟ်ဂကူဆီO)၊ ဂကူဆီမၞိဟ်ယဲဂှ် ပြံင်အာ ဂကူဆီညးမကဵုဒါန်ဂှ်ရ။

ဂကူဆီလ္ၚဵုဂှ် ပံင်နှဴဒၟံင် ကုယဲအာဲကၟာဲ (ယဲမကတဵုဒှ်နူဗဳဇ)၊ ဥပမာ ကေလ် အန္တိဂေန် (Kell antigen) မ္ဂး ပံင်နှဴဒၟံင် ကုယဲ McLeod syndrome။ဂကူဆီလ္ၚဵုဂှ်မ္ဂး စဵုဒၞာကဵု ယဲလ္ၚဵုဂှ် ဟွံသၟဟ်ရထ၊ ဟွံသေင်မ္ဂး စဵုဒၞာကဵုယဲမာန် နွံကီုရ။ 

### သၞောတ် ဂကူဆီ ABO
right|thumb|350x350px|''ABO blood group system'': diagram showing the carbohydrate chains that determine the ABO blood group
သၞောတ်ဂကူဆီ ABO ဂှ် နွံကဵု အန္တိဂေန်ၜါ ကဵု အန္တိဗောဒဳၜါ မဂွံဆဵုကေတ် ပ္ဍဲကဵု ဆီမၞိဟ်။ အန္တိဂေန်ၜါဂှ် အန္တိဂေန် A ကဵု အန္တိဂေန် B။ အန္တိဗောဒဳၜါဂှ် အန္တိဗောဒဳ A ကဵု အန္တိဗောဒဳ B ။ အန္တိဂေန်တအ်ဂှ် နွံ ပ္ဍဲကဵု ကလာပ်ဆီဗကေတ် တုဲ အန္တိဗောဒဳတအ်ဂှ် နွံပ္ဍဲ ဍာ်ဗကေဝ်ဆီ (serum)။ ဂကူဆီမၞိဟ် နကဵုသၞောတ်အန္တိဂေန်ဂှ် ဂွံဆဵုကေတ် သီုဖအိုတ် ၄ ဂကောံ၊ ဂကောံအန္တိ A (ဂကောံ A)၊ ဂကောံအန္တိ B (ဂကောံ B)၊ ဂကောံနွံသီုၜါ A ကဵု B (ဂကောံ AB) တုဲပၠန် ဂကောံ သက်ကုအန္တိဂေန် (ဂကောံ O)။ အန္တိဗောဒဳ မနွံမွဲစွံ ကုအန္တိဂေန်ဂှ် ဂွံဆဵုကေတ် အတိုင်ဗွဲသၟဝ်ဝွံ -

# အန္တိဂေန်	A	ကရောမ် အန္တိဗောဒဳ  B
# အန္တိဂေန်	B	ကရောမ် အန္တိဗောဒဳ  A
# အန္တိဂေန်	AB	ဟွံမဲ ကုအန္တိဗောဒဳ
# အန္တိဂေန်  	သုည (ဂကောံ O) ကရောမ် အန္တိဗောဒဳ A ကဵု B။ 

အန္တိဂေန် ကဵု အန္တိဗောဒဳ ဂကူမကြပ်ရေင်သကအ်တအ်ဂှ် ဒှ်အဂ်ဂလုတဳနေန် (မကောံစန် ကလာပ်ရုပ်) ရေင်သကအ် (ဥပမာ၊ အန္တိဂေန် A ဒှ်အဂ်ဂလုတဳနေန် ကုအန္တိဗောဒဳ A တုဲ အန္တိဂေန် B ဒှ်အဂ်ဂလုတဳနေန် ကု အန္တိဗောဒဳ B)။ ဟိုတ်ဂှ်ရ ကာလမပၠုပ်ဆီမ္ဂး လုကဴ ပ္ဍဲကဵု ဍာ်ဗကေဝ်ဆီ ညးမဒုင်တဲဆီဂှ် ဟွံမဲ ကုအန္တိဗောဒဳ သွက်ကလာပ်ရုပ်ဆီ အန္တိဂေန် ညးတၠဒါန်ဂှ်ရ။ 

သၞောတ်ဆီ ABO ဂှ် ပၞောဝ်ကဵု သၞောတ်ဂမၠိုင်မ္ဂး ဒှ်သၞောတ်ကိစ္စဇၞော်အိုတ် ပ္ဍဲအရာမပၠုပ်ဆီ ကောန်မၞိဟ်တအ်ရ။ အန္တိ-A ကဵု အန္တိ-B တအ်ဂှ် ဗွဲမဂၠိုင် ပံင်ကောံ ကု ဣိမ်မူနဝ်ဂၠောဗုလိန် M (immunoglobulin M)၊ abbreviated IgM ကေုာံ အန္တိဗောဒဳတအ်ရ။ ၜိုန်ရ ဂကူဆီဂှ် ကတဵုဒှ်ကၠုင် နူဂဝ်ကီုလေဝ် ABO IgM အန္တိဗောဒဳတအ်ဂှ် နူကဵု မစုက်လုက် ကုပွဳပွူသဘာဝ မပ္တံကဵု စၞစ၊ ဗက်တေရဳယျာ၊ ဝဳရုသ်တုဲ ကတဵုဒှ်ကၠုင် ပ္ဍဲခန္ဓမၞိဟ်တအ် ပ္ဍဲအခိင်ဘဝသၞာံပထမရ။ ဝေါဟာရ မကော်ဂး ဂကူဆီ A/B/C/ ဂှ် စကော်ကၠာအိုတ် နူသၞာံ ၁၉၀၁ နကဵု ကာလ် လာန်သတိုင်နာ  (Karl Landsteiner) ဗွဲကြဴညိ စၞး C ဂှ် ဒှ်အာ O ။ ဍုင်လ္ၚဵု ကော်စ  *0* (*သုည*)။

### သၞောတ်ဂကောံဆီ Rh
သၞောတ် Rh (Rh ဂှ် ဖ္ဍန်လဝ် နူကဵု *Rhesus*)ဂှ် ဒှ် သၞောတ်မစကာဂၠိုင် မရနုက်ကဵုၜါ (ဝါ) ဒှ်သၞောတ်တၟေင် မရနုက်ကဵု ဒုတိယ ပ္ဍဲကဵု သၞောတ်ဆီ ကောန်မၞိဟ် ကာလမပၠုပ်ဆီ မနွံကဵု အန္တိဂေန် ပြဟ်ဟ်ဏအ် ၅၀ ဂကူ။ အရာတၟေင် Rh အန္တိဂေန် ဂှ် ဒှ် D အန္တိဂေန်၊ မုဟိုတ်ရောမ္ဂး ဍေဟ်ဒှ်အရာ မပခိုဟ်ကဵု ဓါတ်ဣိမ်မုန် မနွံကဵု Rh အန္တိဂေန်အဓိက မသုန်သာ်ဂှ်ရ။ ဗွဲဓမ္မတာမ္ဂး D-negative ဂှ် ဟွံကလိဂွံ အန္တိ-D IgG ဟွံသေင်မ္ဂး IgM အန္တိဗောဒဳ၊ မုဟိုတ်ရောမ္ဂး အန္တိ-D အန္တိဗောဒဳဂှ် ဗွဲမဂၠိုင် ဟွံပ္တိတ် နကဵု အရာမကလေင်ဂတးမာန် သွက်ဒစဵုဒစး ရုပ်ဝတ္ထု ဗွဲသဘာဝရ။ ၜိုန်ဂှ်လေဝ် D-negative နကဵုမဖန်ဗဒှ်မ္ဂး ပ္တိတ် IgG anti-D အန္တိဗောဒဳဂမၠိုင်မာန်ကီုရ။ ယဲ Rh ဂမၠိုင် ကတဵုဒှ် နကဵုဟိုတ်နူဏအ် မာန်ဒၟံင်ကီုရ။ Rh negative blood types are much less common in Asian populations (0.3%) than they are in European populations (15%). ပ္ဍဲကဵုလက္သန်မ္ဂး Rh(D) နွံကီု ဟွံမဲကီုဂှ် ဗၟံက်ထ္ၜးလဝ် နကဵု လက္သန် + ဟွံသေင်မ္ဂး − ၊ ဟိုတ်ဂှ်ရ ကာလချူ ဥပမာ ဂကူဆီ ဂကောံ A− မ္ဂး မဂွံအဓိပ္ပါယ် ပ္ဍဲကဵု သၞောတ် ABO မ္ဂး ဒှ်ဂကူဆီ A တုဲ ဟွံမဲ ကု Rh (D)။

## သၞောတ် ABO အကြာ အံက် ကဵု ကောန်
သၞောတ်ဂကောံဆီ ABO ကာလမတီလဝ် ဂကူဆီ အံက်ၜါလပါ်တုဲ ဂကူဆီကောန် မဒှ်မာန် (သ္ၚိအင်လတူ)၊ သၞောတ်ဂကောံ ABO ကာလမတီလဝ် ဂကူဆီ မိအံက် ကေုာံ ကောန် တုဲ ဂကူဆီအပါ လဵုဒှ်မာန်။ 

thumb|left|500px|သ္ၚိအင် နဲတၟော် ဂကူဆီ အကြာအံက် ကေုာံ ကောန်



## Clinical significance

### Blood transfusion
Transfusion medicine is a specialized branch of hematology that is concerned with the study of blood groups, along with the work of a blood bank to provide a transfusion service for blood and other blood products. Across the world, blood products must be prescribed by a medical doctor (licensed physician or surgeon) in a similar way as medicines.
right|thumb|235x235px|Main symptoms of acute hemolytic reaction due to blood type mismatch.
Much of the routine work of a blood bank 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 between a donor and recipient, a severe acute hemolytic reaction with hemolysis (RBC destruction), kidney failure 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 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. It is also possible to use the patient's own blood for transfusion. This is called autologous blood transfusion, which is always compatible with the patient. This is because the patient's own red blood cells are used. The procedure of washing a patient's own red blood cells goes as follows: The patient's lost blood is collected and washed with a saline solution. The washing procedure yields concentrated washed red blood cells. The last step is reinfusing the packed red blood cells into the patient. There are multiple ways to wash red blood cells. The two main ways are centrifugation and filtration methods. This procedure can be performed with microfiltration devices like the Hemoclear filter. Risks can be further reduced by cross-matching 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 with a microscope. 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 labelling has been standardized using a barcode system known as ISBT 128.

The blood group may be included on identification tags or on tattoos worn by military personnel, in case they should need an emergency blood transfusion. Frontline German Waffen-SS had blood group tattoos during World War II.

Rare blood types can cause supply problems for blood banks and hospitals. For example, Duffy-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, where blood services may endeavor to encourage Westerners to donate blood.

### Hemolytic disease of the newborn (HDN)
A pregnant woman may carry a fetus with a blood type which is different from her own. In those cases, the mother can make IgG blood group antibodies. This can happen if some of the fetus' blood cells pass into the mother's blood circulation (e.g. a small fetomaternal hemorrhage at the time of childbirth or obstetric intervention), or sometimes after a therapeutic blood transfusion.  This can cause Rh disease or other forms of hemolytic disease of the newborn (HDN) in the current pregnancy and/or subsequent pregnancies.  Sometimes this is lethal for the fetus; in these cases it is called hydrops fetalis. If a pregnant woman is known to have anti-D antibodies, the Rh blood type of a fetus 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. 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 banks fractionate some whole blood into several products. The most common of these products are packed RBCs, plasma, platelets, cryoprecipitate, and fresh frozen plasma (FFP).  FFP is quick-frozen to retain the labile clotting factors V and VIII, which are usually administered to patients who have a potentially fatal clotting problem caused by a condition such as advanced liver disease, overdose of anticoagulant, or disseminated intravascular coagulation (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 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
right|thumb|230x230px|'''Red blood cell compatibility chart'''<br /><br />In addition to donating to the same blood group; type O blood donors can give to A, B and AB; blood donors of types A and B can give to 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.  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
right|thumb|312x312px|'''Plasma compatibility chart'''<br /><br />In addition to donating to the same blood group; plasma from type AB can be given to A, B and O; plasma from types A, B and AB can be given to O.
Blood plasma compatibility is the inverse of red blood cell compatibility. Type AB plasma carries neither anti-A nor anti-B antibodies and can be transfused to individuals of any blood group; but type AB patients can only receive type AB plasma. Type O carries both antibodies, so individuals of blood group O can receive plasma from any blood group, but type O plasma can be used only by type O recipients.


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
right|thumb|220x220px|A hospital worker takes samples of blood from a donor for testing
In transfusions of packed red blood cells, individuals with type O Rh D negative blood are often called universal donors. 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 (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 exceptionally strong anti-A, anti-B or any atypical blood group antibody may be excluded from blood donation. In general, while the plasma fraction of a blood transfusion may carry donor antibodies not found in the recipient, a significant reaction is unlikely because of dilution.

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

For 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, because it does not contain any anti-A or anti-B antibodies.

## Blood typing
Typically, blood type tests are performed through addition of a blood sample to a solution containing antibodies corresponding to each antigen. The presence of an antigen on the surface of the blood cells is indicated by agglutination. An alternative system for blood type determination involving no antibodies was developed in 2017 at Imperial College London which makes use of paramagnetic molecularly imprinted polymer nanoparticles with affinity for specific blood antigens.  In these tests, rather than agglutination, a positive result is indicated by decolorization as red blood cells which bind to the nanoparticles are pulled toward a magnet and removed from solution.

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
Blood types were first discovered by an Austrian physician, Karl Landsteiner, working at the Pathological-Anatomical Institute of the University of Vienna (now Medical University of Vienna). In 1900, he found that blood sera from different persons would clump together (agglutinate) when mixed in test tubes, and not only that, some human blood also agglutinated with animal blood. He wrote a two-sentence footnote:
 
This was the first evidence that blood variation exists in humans. The next year, in 1901, he made a definitive observation that blood serum of an individual would agglutinate with only those of certain individuals. Based on this he classified human bloods into three groups, namely group A, group B, and group C. He defined that group A blood agglutinates with group B, but never with its own type. Similarly, group B blood agglutinates with group A. Group C blood is different in that it agglutinates with both A and B. This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930. (C was later renamed to O after the German *Ohne*, meaning without, or zero, or null.) The group AB was discovered a year later by Landsteiner's students Adriano Sturli and Alfred von Decastello.

In 1927, Landsteiner, with Philip Levine, discovered the MN blood group system, and the P system. Development of the Coombs test in 1945, the advent of transfusion medicine, and the understanding of ABO hemolytic disease of the newborn led to discovery of more blood groups. , the International Society of Blood Transfusion (ISBT) recognizes 38 blood groups.

## Society and culture
A popular pseudoscientific belief in Japan (known as *"ketsueki-gata"*) (血液型) and South Korea is that a person's ABO blood type is predictive of their personality, character, and compatibility with others. Researchers have established no scientific basis exists for blood type personality categorization, and studies have found no "significant relationship between personality and blood type, rendering the theory 'obsolete' and concluding that no basis exists to assume that personality is anything more than randomly associated with blood type."

## See also

* Blood type (non-human)
* Human leukocyte antigen
* hh blood group

## References

## Further reading

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## External links

* BGMUT Blood Group Antigen Gene Mutation Database at NCBI, NIH has details of genes and proteins, and variations thereof, that are responsible for blood types
* Online Mendelian Inheritance in Man (OMIM): ABO Glycosyltransferase; ABO - 110300
* Online Mendelian Inheritance in Man (OMIM): Rhesus Blood Group, D Antigen; RHD - 111680
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ကဏ္ဍ:ပြန်လည်မဆန်းစစ်ရသေးသော ဘာသာပြန်များပါဝင်သည့် စာမျက်နှာများ