ABO Blood group System

lANDSTEINER BLOOD GROUP CLASSIFICATION

ABO blood grouping is based on the principle of “Agglutination reaction“. It is the popular method for blood group identification which determines the presence and absence of cellular antigens which are of two types A and B. According to the ABO-blood group system, there are four blood groups namely A, B, AB and O.

The blood typing or the blood group identification performed by the blood-test kit that contains anti-A, anti-B and anti-D antisera.

Content: ABO Blood group System

  1. Principle
  2. History
  3. Overview
  4. Method
  5. Interpretation of Result
  6. Facts
  7. Conclusion

Principle of ABO Blood group System

In the ABO blood grouping system, agglutination reaction takes place between the surface proteins that are found on the red blood cell surface. This surface protein refers to “Antigen” which also refers to as “Agglutinogen”. The antigens are mainly glycoproteins which are of two types namely self-antigen and foreign-antigen.

If the antigen is foreign, it will induce the immune response by which WBCs recognizes these antigens. Then these WBCs starts making “Antibodies” against that particular antigen. Antibodies are the molecules that work against the antigen also refers to “Agglutinins” that floats in the blood plasma.

History

Year of discoveryDiscovererDiscovery
1900Karl LandsteinerDiscovered the ABO blood group system
1901Karl LandsteinerClassify human blood into A, B & C group based on agglutination reaction
1907Jan JanskyClassify blood type O, A, B & AB in roman letters I, II, III & IV
1907Reuben OttenbergIntroduces blood typing in transfusion
1910Ludwik Hirszfeld and Emil Freihers Von DungernDescribed genetic inheritance of blood group
1914-15Blood clot prevention technique was introduced during first world war by citric acid
1924Felix BernsteinIntroduced the blood group inheritance pattern for multiple alleles
1927Karl LandsteinerABO blood group system was accepted by National Research Council
1930Karl LandsteinerAwarded by Nobel prize in physiology and medicine
1950ABO blood group system was universally followed
1978FinneDescribed the presence of polylactosamine chains in the human erythrocyte glycoproteins

Overview

According to the ABO blood group system, there are four blood groups namely A, B, AB and O.

Ablood group: In ‘A’ blood group, A-surface antigens are present on the RBC membrane, and the antibodies in the blood plasma are anti- B.

blood type A

Bblood group: In ‘B’ blood group, B-surface antigens are present on the RBC membrane, and the antibodies in the blood plasma are anti- A.

blood type B

ABblood group: In ‘AB’ blood group, the surface antigens on the RBC membrane are A and B- antigens and no antibodies in the blood plasma.

blood type AB

Oblood group: In ‘O’ blood group, there are no surface antigens present on the RBC membrane, and the antibodies in the blood plasma are both antiA and antiB type.

blood type O

Method of ABO Blood group System

ABO blood group method can be performed by the “Slide technique” which includes the following steps:

protocol of ABO blood group system

  1. First, scrub the middle finger with cotton saturated with 70% of alcohol.
  2. Then, prick the middle finger by sterilized needle or lancet.
  3. After that, place three drops on a clean glass slide.
  4. Then after this, add antisera in a sequence of anti- A in a first drop, anti- B in a second drop and anti- D to the third drop respectively.
  5. Mix the blood with the antisera with the help of a separately sterilized toothpick.
  6. Allow the slide to stand for 2-3 minutes and then note down the results on the basis of clump formation or agglutination reaction.

Interpretation of Result

The results on ABO blood group system are made On the basis of agglutination reaction like:

ABO BLOOD TYPIND BASED ON AGGLUTINATION REACTION

  • If the agglutination occurs in the RBCs to which anti-A is added, then the blood group is ‘A’.
  • If agglutination occurs in the RBCs to which anti-B is added, then the blood group is ‘B’.
  • If the agglutination occurs in the RBCs to which both anti-A and B is added, then the blood group is ‘AB’.
  • If there is no agglutination occurs in the RBCs, then the blood group is ‘O’.

In addition to this, there is also another antiserum that is anti-D which determines the positive and negative blood type.

  • If the agglutination occurs in the RBCs to which anti-D is added, then the blood type is positive (+) whereas if no agglutination occurs in the RBCs to which anti-D is added, then the blood type is negative (-).

Facts about ABO Blood group System

If agglutination occurs in the RBCs, then the corresponding antibody must be absent in the blood plasma. The antigens if absent on the RBCs membrane, then the corresponding antibodies must be present in the blood plasma.

Individuals above 3-6 month have naturally occurring antibodies which arise without any antigenic stimulation from the maternal placenta. These antibodies belong to the IgM class.

ABO blood group is also present in some other animals like gorillas, chimpanzees etc.

Theory of blood transfusion says that before transfusion, the ABO compatibility of blood type must be checked otherwise it can affect the immune system.

  • A person with blood group A can receive blood from the person with blood types A and O.
  • The person with blood group B can receive blood from the person with blood types B and O.
  • A person with blood group AB can receive blood from the person with all blood types A, B, AB and O and refers to “Universal recipient”.
  • The person with blood group O can receive blood from only the person with blood type O.
Recipient blood typeCan take blood from the person with blood type
AA and O
BB and O
ABA, B, AB and O
OO
  • A person with blood group A can donate blood to the person with blood types A and AB.
  • The person with blood group B can donate blood to the person with blood types B and AB.
  • A person with blood group AB can donate blood to only the person with blood type AB.
  • And, a person with blood group O can donate blood to the person with all blood types A, B, AB and O and hence it refers to “Universal donor”.

Donor blood typeCan give blood to the person with blood type
AA and AB
BB and AB
ABAB
OA, B, AB and O

Conclusion

Therefore, the ABO blood group system is one of the popular technique to classify human blood. ABO blood group system majorly classifies the blood into four types that is A, B, AB and O.

Agglutination reaction determines the ABO blood type which characterizes by the clump formation in the blood. ABO blood group system accepts by the National Research Council and popularly known as “Landsteiner classification“.  Karl Landsteiner won the Nobel prize in the year 1930 for his contribution in this.

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