What special blood do you know? How rare is it?

Let me explain to you what special blood do you know? How rare is it? Let's give you a brief introduction! Some people's blood can help make drugs to prevent hemolysis of newborns, and some people can find millions in their blood ... What "special lineages" do you know?

0 1 Among these 342 blood group antigens, almost 160 are "high frequency antigens", that is to say, these antigens can be found on most people's red blood cells. If you lack an antigen that is positive for 99% of the people in the world, your blood is "rare". If you lack an antigen that is positive for 99.99% of the people in the world, your blood is "extremely rare".

If your red blood cells lack some high-frequency antigen, you are the "negative" blood of this blood group system. If you receive blood from a "positive" blood donor, the antibodies in your body will interact with this mismatched foreign blood cell, triggering a further reaction of the immune system. This transfusion reaction can be fatal.

As the name implies, there are too few people with rare blood, so there is almost no need to use rare blood. However, once there is such a demand, finding a blood donor and delivering his blood to patients will become a suffocating race against time. This process almost always involves complex international cooperation. People involved often hide behind the noise of "normal" blood donation, track down a suitable blood donor through unknown work, and then fly blood bags from one country to another.

Blood of gold

Forty years ago, when Thomas, aged 10, entered the Geneva University Hospital because of a common pediatric infection, his blood test showed a very strange result: one of his blood type systems seemed to be completely missing.

Some genes carry information to produce corresponding antigens. According to these genes, the blood group system can be divided into 35 categories. Most of the 342 blood group antigens belong to one of these 35 blood group systems. Rh system (formerly known as' rhesus monkey' system) is the largest one, including 6 1 antigen.

Among many antigens in Rh system, D antigen is the most important one. White people often lack D antigen, and about 15% of white people are Rh D negative blood (although it is not accurate, this blood type is commonly known as Rh negative blood). Thomas seems to have deleted all the antigens of Rh system. If this suspicious test result is confirmed, his blood type will be "Rhnull"-the rarest blood type in the world. This is also an extraordinary discovery in the hematology department of this hospital.

Rh deficiency blood group was first recorded in 196 1 year, which was owned by an Australian indigenous woman. Before that, doctors thought that embryos without all Rh blood cell antigens could not survive at all, and naturally they could not grow up. Up to 20 10, nearly 50 years later, 43 cases of Rh-deficient blood individuals have been reported worldwide.

Dr Marie-José Stelling, then director of hematology and immunology laboratory of Geneva University Hospital, couldn't believe what she saw, so she sent Thomas' blood sample to Amsterdam for analysis and then to Paris. All the analysis results confirmed her findings: Thomas' blood type was Rh deficient.

The discovery of human blood type has a history of 100 years. As early as 1900, Landsteiner of the University of Vienna discovered the human ABO blood group system, and scholars all over the world began to study blood groups. /kloc-since 0/00 years, people have found that various blood components in blood have their own types. Blood groups A, B, O and AB are ABO systems on red blood cells. In fact, there are more than 20 blood group systems such as Rh, MN and P on red blood cells. In addition, white blood cells, platelets, serum proteins, erythrocyte enzymes and other blood components in the blood all have their own blood types. At present, more than 600 blood group antigens have been found. Except identical twins, it is difficult to find two people with the same blood type in the crowd.

Rare blood group refers to a kind of rare blood group, and almost every blood type system has some rare blood group. For example, some AB subtypes of ABO blood group: Aint, Ax, Am, Ael, B2, Bx, Bm, AxB, etc. A special form of Mumbai type in antigen biosynthesis. (Oh) And Mumbai style. P blood group p, P 1k, p2k. Blood groups other than red blood cell blood group and chimera blood group. Fy(a-) is in Duffy blood group, etc.

The so-called panda blood refers to RH negative blood. In fact, this rarity is relative to our country, because RH-negative only accounts for three thousandths of the Han population in China, while whites account for about 15% and blacks account for about 4%.

03 Rh negative blood

Rh (abbreviation of monkey mokey) blood group is the second largest blood group system of red blood cell blood group, and its antigenicity and clinical significance are second only to ABO blood group. The vast majority of Han people in China are Rh-positive blood, and Rh-negative blood is a kind of rare blood group, which is very rare in China, with an average incidence of only one thousandth to three thousandths. If it is assigned to blood types A, B, O and AB, the proportion is even less than one thousandth. Therefore, once this part of the population needs blood transfusion, it is often difficult to supply blood.

If patients with Rh negative blood are given Rh positive blood, they will easily produce Rh antibodies. Re-transfusion of Rh-positive blood will lead to severe hemolysis and endanger the life of patients. Therefore, Rh positive patients can receive Rh negative blood, and vice versa. In recent years, with the progress of blood transfusion science, more and more attention has been paid to special blood types. At present, the provincial blood center has screened out more than 100 Rh-negative blood donors and established files.

Genes and blood types

First, an overview of blood

Blood consists of four components: plasma, red blood cells, white blood cells and platelets. Plasma accounts for about 55% of blood and is a mixture of water, sugar, fat, protein, potassium salt and calcium salt. It also contains many chemicals necessary to stop bleeding and form blood clots. Blood cells and platelets make up another 45% of the blood.

There are two kinds of blood cells: red blood cells and white blood cells. Most red blood cells look like rings with holes and can't wander around. Red blood cells contain a special protein called hemoglobin. This protein makes red blood cells look red. It can transport oxygen from the lungs to the whole body and concentrate carbon dioxide from the whole body to the lungs. Although blood contains many non-red blood cells, there are so many red blood cells that the blood itself is red.

White blood cells are round and much larger than red blood cells, which can produce a kind of protein called antibody to help the body resist infections caused by bacteria, viruses and foreign bodies.

Platelets are actually not cells, but fragments of cells. When we are injured, platelets gather and stick around the wound, producing chemicals that start the coagulation mechanism, and blood stops flowing.

Second, what is the blood type?

Everyone has a blood type. The most commonly used blood type classification method is ABO classification system invented by Karl Landsteiner in the early 1920s, including four blood types: A, B, AB and O. Your blood type is determined by the genes inherited from your parents before you were born. We inherited a large number of genes, half from mother and the other half from father. These genes combined to determine the blood type, thus producing a protein called agglutinin on the surface of red blood cells.

There are alleles of three blood group genes: A, B and O. Since everyone has copies of two genes, there are six possible combinations: AA, BB, OO, AB, AO and BO. In genetic terminology, these combinations are called genotypes and contain genes inherited from parents.

In addition to protein's lectin in red blood cells, other genes also produce a protein called coagulation hormone, which runs in plasma. The role of lectin is to ensure that there is only one blood type of blood cells in your blood.

Third, genotype determines blood type.

The lectin produced by O allele has no special enzyme activity, while the lectin produced by A and B alleles has its own enzyme activity. Therefore, people with OO genotype are type O blood, that is to say, the lectin on their red blood cells has no enzyme activity, and the blood will contain lectins A and B. Lectin A destroys type A blood cells that may enter the human blood circulation, and lectin B destroys type B blood cells.

People with AA genotype belong to type A blood because the lectin on their red blood cells has enzymatic activity. People with genotype AO also have enzyme activity related to allele A, so they also belong to type A blood. (Remember that the O allele has no enzymatic activity! ) People with type A blood have lectin B in their plasma, which destroys type B blood cells that enter the body's blood circulation.

Similarly, people with BB and BO genotypes belong to type B blood. These people have lectin A in their plasma, which will destroy any type B blood cells that enter the blood circulation.

People with genotype AB have enzyme activities related to both A and B alleles, and there is no lectin in their plasma.

The concepts of genotype and phenotype are easy to understand from the examples of blood types. Genotype refers to the real gene that a person has that determines a certain characteristic, and phenotype refers to the characteristics that a person shows. In the case of blood type, genotypes AA and AB make people show the phenotype of blood type A, and similarly, genotypes BB and BO show the phenotype of blood type B. People with phenotypes of O and AB can only have one genotype, namely OO and AB.

In different parts of the world, the population distribution of blood groups A, B, O and AB is different. The figure below shows the proportion of each blood type in different parts of the world.

O A group

USA: 289.499.438+032.080

Australia 427.391.115.066

Bolivia, India

China

Denmark: 423.434.5438+00 1.042

Eskimo: 472.452.059.5438+07

France: 10000.100000000005

Ireland+006.10066.100600000006

Nigeria

St Louis, Anna, USA, white +03.099. 59696.8888888866 1

African-Americans in Iowa, USA+0.265+0.265.20089.00000000005

The detection rate of blood type is determined by the number of A, B and O alleles found all over the world. When people from all over the world immigrate and mix on a larger scale, the distribution of different blood types will become more and more balanced.

Fourth, what is blood transfusion?

Because there are only four blood types, it is possible to draw blood from one person and input it to another. This is called blood transfusion. In order to make blood transfusion successful, it is necessary to make the lectin on the surface of donor red blood cells correspond to the lectin of recipient. In other words, the blood types of the donor and the recipient must match, otherwise the antibodies (lectins) in the recipient's blood will attack the blood cells of the donor and form blood clots through agglutination reaction.

If you need a blood transfusion, someone will take your blood sample to test your blood type and decide whose blood type it is. People with type A blood can receive blood from people with AA, AO and OO genotypes, while people with type B blood can receive blood from people with BB, BO and OO genotypes.

Five, two special blood types during blood transfusion: OO and AB.

People with type O blood are called universal blood donors because their blood can be donated to anyone, but they can only accept type O blood. Type O blood does not carry lectin A or B, and the immune system regards lectin as a foreign body. People with blood type O have lectins against lectins A and B, so if they have blood type A, B or AB, the body cannot avoid agglutination.

People with the second special blood type AB are called universal recipients because they can accept all four blood types. There are lectins A and B on the surface of red blood cells of type AB blood, and the body's immune system regards them as a part of itself-not a relic. Type AB blood can not produce agglutinin against agglutinin A and B, so type A, B, AB and O blood will not produce agglutination reaction.

Forty years ago, Thomas, who was only 10 years old, came to Geneva University Hospital because of infection. His blood test showed very strange results, and he didn't seem to belong to any known blood type. According to the genes that carry the information of antigen production, it can now be divided into 35 blood group systems. Most of 342 antigens will appear in some blood group systems. Rh system is the largest, containing 6 1 antigen. The most important antigen in Rh system is D antigen, but Caucasians usually lack this antigen. But Thomas seems to lack all Rh antigens. If this guess is true, his blood type is Rhnull, which is one of the rarest blood types in the world.

Rhnull blood group 196 1 was first found in an Australian aboriginal woman. Before that, doctors thought that embryos lacking all Rh blood cell antigens could not survive, let alone develop normally or even grow up. By 20 10, that is, more than 50 years later, 43 people with Rhnull blood type were found all over the world. I can't believe what I saw. Marie-José Stelling, the head of the blood and immune blood laboratory of Geneva University Hospital, sent Thomas' blood to Amsterdam and Paris for analysis. The results confirmed her discovery that Thomas did have Rhnull blood type, which made him a medical and scientific person? Treasure? .

Researchers are trying to solve the mystery of physiological function in complex Rh system, so they are eager to get Rhnull blood type because it can provide perfection? Eliminate the system? . Rare negative blood is so popular that even if the blood stored in blood banks is anonymous, scientists sometimes try to track blood donors and contact them directly to get blood. For all people in rare blood group with Rh system, Rhnull blood group can be regarded as? Universal blood? Because of this, its life-saving ability is enormous. Because of this, Rhnull blood group is highly valued by doctors. Although only after careful consideration, it will be lost to patients in extreme cases because it is almost irreplaceable. Thierry Pilade, director of the French National Immunohematology Reference Laboratory, said? This is golden blood. ?

We know that many higher animals, including humans, have red blood cells (erythrocytes) and white blood cells (leukocytes) in their blood. Through the movement of red blood cells, oxygen is transported into the blood and carbon dioxide is discharged to maintain life. White blood cells are responsible for swallowing bacteria and foreign bodies, and people call them guardians of life. The blood of horseshoe crab is light blue. There is only one kind of cell called "abnormal cell". The deformed cells of horseshoe crab contain a substance called hemocyanin, which is light blue because its molecules contain copper ions. However, among the red blood cells of higher animals, the deformed cells in the blood of horseshoe crabs have a special ability. When a large number of bacteria invade the blood of horseshoe crabs, deformed cells can quickly coagulate and devour them when they come into contact with bacteria.

Of course, it can't resist the fierce attack of many bacteria. When deformed cells are broken and disintegrated by bacteria one by one, cell fragments shrink rapidly and blood coagulates rapidly, the life of horseshoe crab is over. The metamorphic cells of horseshoe crab can do all kinds of deformation actions, first oval, then triangle, long ... irregular, and many pseudopods of different lengths protrude around the cytoplasm.

After long-term research, scientists have extracted a substance from the deformed cells of limulus, which comes from intracellular particles and is called limulus reagent. Limulus lysate reagent can accurately and quickly reflect endotoxin by using the characteristics of rapid coagulation of limulus amebocyte after contact with bacteria. In this way, the fatal weakness of horseshoe crabs has become active service for mankind. Take limulus lysate and drip it directly into cerebrospinal fluid. Like transparent colloid, limulus lysate is firmly solidified at the bottom of the bottle. It was quickly detected that the child had bacterial meningitis, which quickly provided a basis for diagnosis. For example, injections from various pharmaceutical factories have to go through pyrogen inspection before leaving the factory. The so-called pyrogen is "endotoxin". As long as the injection contains viral substances, it can't escape.