Monday, June 28, 2021

Blood Types & ABO Blood Group Test: What Blood Type Are you have ?

Blood Types & ABO Blood Group Test: What Blood Type Are you have?

Blood Types  

Human blood is not the same, people belong to different blood groups, depending on the surface markers found in red blood cells. The cells that form the tissues and the body organs are covered by surface or antigens indicators. Red blood cells are no different. While the blood of all is composed of the same basic parts, there is a lot of variety in the types of blood that exist. There are eight different types of blood and the type you have depends on the genes you inherited from your parents

Polymorphisms that are suspected to be present on the surface of red blood cells but only detected by other means, such as DNA sequencing, are not blood groups. Furthermore, the antibodies must be alloantibodies, suggest that some individual lacks the blood group. The polymorphisms of the blood group can be fundamental as representing the presence or absence of complete macromolecule (example, RhD), or minor as a single change of amino acid (example, Fya and Fyb) or a single difference monosaccharide (example, A and B)

Blood group antigens may be:

• proteins

• glycoproteins, with the antibody identifying primarily the polypeptide backbone

• glycoproteins, with the antibody identifying the carbohydrate moiety

• glycolipids, with the antibody identifying the carbohydrate portion

Blood Groups

What is the definition of blood group? Taken literally, any variation or polymorphism found in the blood could be considered a blood group. However, the term blood group is generally limited to antigens on the surface of red blood cells

An antigen is any substance that the immune system can respond to. For example, bacterial cell wall components can trigger severe and immediate neutrophil attacks. If the immune system finds an antigen that is not found in the body's cells, it will launch an attack on that antigen. Conversely, the antigens found on the body's cells are known as "autoantigens" and the immune system does not normally attack them. The membrane of each red blood cell contains millions of antigens that the immune system ignores. However, when patients receive blood transfusions, their immune system will attack the donor's red blood cells which contain antigens that differ from their autoantigens. Therefore, ensuring that the antigens of the transfused red blood cells match those of the patient's red blood cells is essential for a safe blood transfusion

On their surface, red blood cells carry agglutinogens, substances that antibodies can fight. Of the hundreds of agglutinogens identified, there are two in particular that are used to determine different blood groups. Groups A and groups B the carriers of agglutinogens A and B, while group AB designates the carriers of both agglutinogens. Finally, group O corresponds to those who do not have any. Plasma contains antibodies that react with agglutinogens that are not normally found in our blood. In the case of blood transfusion, therefore, it is essential to guarantee the compatibility of the donor and recipient blood, to avoid any rejection phenomenon

Group A: the surface of the red blood cells contains antigen A and the plasma has anti-B antibodies. The anti-B antibody would attack blood cells that contain the B antigen. 

Group B: the surface of the red blood cells contains the B antigen and the plasma has anti-A antibodies. The anti-A antibody would attack blood cells that contain the A antigen.

Group AB: Red blood cells have A and B antigens, but plasma does not contain anti-A or anti-B antibodies. People with type AB can receive any type of ABO blood.

Group O: Plasma contains anti-A and anti-B antibodies, but the surface of red blood cells does not contain A or B antigens. Since these antigens are not present, a person with any ABO blood group can receive this type of blood.

Rhesus system

• An antigen that is sometimes found on the surface of red blood cells is the Rh factor which takes its name from the Rhesus monkey in which it was first discovered. Of the UK population, 85% are Rh + ve, which means that Rh antigens are present. The other 15% is Rh-ve

• If a Rh person receives a blood transfusion that has Rh + antigens, anti-Rh + antibodies will form which will react with the Rh + antigen and aggregation (agglomeration) will occur

• The most serious problem with Rh incompatibility happens during pregnancy. If the mother is Rhand, the father is Rh +, the child can inherit the dominant Rh + (gene) allele from the father. The baby's Rh + blood will enter the mother's blood during labor, causing her to develop antibodies to the Rh factor

• If a second Rh + baby is later conceived, the mother's antibodies cross the placenta and attack the blood of the fetus, causing a condition known as rhesus baby syndrome. Symptoms include liver damage and fewer red blood cells, brain (due to lack of oxygen) and skin

• To avoid this, each Rhmother will automatically receive an injection of anti-Rh + antibodies (confusedly known as anti-D) during labor. These antibodies attack and destroy all Rh + antigens in the mother's blood, preventing her from sensitizing to Rh + antigen. This causes your body to believe that you have not had a Rh + ve baby, so your next pregnancy will be protected from seizures as you will have no Rh + ve blood antibodies

If a baby inherits RH + blood from the father and the mother is RH-, problems can develop if the mother and baby's blood cells mix during birth

Donate Blood

A+: This is one of the most common blood types. Someone with this type can give blood to people who are A positive or AB positive.

A-: Someone with this rare type can give blood to anyone with A or AB blood type.

B+: Someone with this rare type can give blood only to people who are B positive or AB positive.

B-: Someone with this very rare type can give blood to anyone with B or AB blood type.

AB+: People with this rare blood type can receive blood or plasma of any type. They’re known as universal recipients.

AB-: This is the rarest blood type. a person with this blood type is known as a “universal plasma donor,” because anyone can receive this type of plasma.

O+: This is one of the most common blood types. Someone with this can donate blood to anyone with a positive blood type.

O-: Someone with this rare blood type can give blood to anyone with any blood type.

Universal donor and universal recipient

O negative blood contains no A, B, or RhD antigens.Type O negative red blood cells are considered the safest to give to anyone in a life-threatening emergency or when there’s a limited supply of the same blood type. Almost person with any blood type can receive these red blood cells. A person with group O negative blood is a universal donor. The rules for plasma are the opposite of those for Rh system. A universal plasma donor will carry type AB blood

  • A person with O-negative blood can give to almost anyone.
  • A person with Rh-negative blood can give to someone with Rh-negative or Rh-positive blood.
  • A person with Rh-positive blood can only give to person with Rh-positive blood.

Methods of blood group determination

Blood are polymorphic serological characteristics of the erythrocyte membrane determined by their reaction with a specific antiserum. The reagents which have been used to identify red cell antigens are either

• Naturally occurring antibodies

  1. Alloantibodies (or isoantibodies) which occur spontaneously within the ABO system and in rare phenotypes of other blood group systems
  2. monoclonal antibodies produced in certain pathological conditions (exemple, the cold agglutinins in autoimmune diseases)

• Immune antibodies, induced by pregnancies, blood transfusions or active immunisation of humans and animals

• lectins, of plant and animal origin. Due to their easy accessibility and their high epitope specificity, these reagents have been widely used in structural investigations

• hybridoma antibodies, which can be produced in great quantities and show a clear-cut specificity comparable to that of the highly specific alloantibodies

Modern molecular biological methods have recently been introduced into blood group research: the polymerase chain reaction (PCR) to determine blood group genotypes, and DNA restriction fragment length polymorphism to establish the chromosomal location of blood group genes

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