Abo Blood groups

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ABO Blood Group System

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Discovery of ABO Groups (1901)

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ABO Blood Group System

Discovered by Karl Landsteiner in 1901

Three blood groups- A, B and O

Fourth group AB discovered by Descastello and

Sturli in 1902

Landsteiner’s Rule - Reciprocal antibodies present in

serum to antigens lacking on the red cells

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Inheritance of ABO Blood Groups

Follows Mendelian principles

A and B genes co-dominant

O gene is amorphic

Three allelic genes -A, B & O

ABO gene on chromosome 9q34

Discovered by Yamamoto in 1990

A gene - 1062 bp

B gene - 1062 bp

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Structure of the Red Cell Membrane

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Bombay Phenotype

First reported by Bhende, Bhatia et al in Bombay in 1952

Red cells lack A, B and H antigens

Serum has anti-A, anti-B and anti-H antibodies

Red cells show no reaction with anti-H

Frequency of this group in Bombay estimated to be about

1 in 7600 while in South West districts of Maharashtra

about 1 in 4500

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Inheritance of ABO and Bombay Phenotype

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Development of ABO Antigens & Antibodies

Antigens - 6th week of fetal life Full expression -3 years after birth Glycoproteins, can be Glycolipids or Glycosphingolipids present on most tissues

RBC, endothelial cells, platelets, lymphocytes, epithelial cells.

Soluble form in secretions saliva, tears, urine, bile, milk, digestive juice, amniotic

fluid

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Antibodies- after first few months of life too low for detection until 3- 6 months of age Antibody levels- peak at 5 to 10 years of age Immunoglobulin class – usually IgM and few IgG Activate compliments Naturally occurring antibodies

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Clinical significance• Cause immediate intravascular red cell destruction • Which can give rise to severe and fatal HTR.

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• Seldom cause HDN , usually mild

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Blood Group A

A antigen

Anti-B

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Blood Group B

B antigen

Anti-A

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Blood Group AB

B antigen

A antigen

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Blood Group O

B antigen

A antigen

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The ABO Blood Group System

Blood group Antigen on RBC Antibody in plasma

A A Anti- B

B B Anti-A

AB A &B No antibody

O No antigen Anti-A & Anti-B

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Blood Grouping

Cell grouping- test RBCs with Standard antisera

Serum grouping- test serum with known cells

Discrepancy if cell and serum grouping do not

agree

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Conventional tube method

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Results in Tube method

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Reading in tube method

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ID-Micro Typing System (Gel Test)

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Grading of Reactions

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Matching blood groups for Transfusion

Recipient blood group Donor blood group

A A or OB B or OAB (Universal Recipient) A, B, AB or OO O (Universal Donor)Bombay ‘O’ Bombay ‘O’Rh+ Rh+, Rh-Rh- Rh-

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Rh and other important

Blood Group Systems

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Rh Blood Groups

Over 52 antigens comprises the Rh blood group system. Rh D is the most potent antigen amongst all. other important antigens C, E, c, eNon glycosylated proteinsRh antibodies – immune antibodiesAntibodies are clinically significant as causes HTR or HDN.

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Other Blood Groups

• 26 blood groups have been known

Routinely not typed As antibodies are not of the regular occurrence Most of the antigens are not potent to stimulate antibody

Recipient having antibody to the antigen present on donor’s red cells may experience reaction.

Cross matching / antibody screening detects such antibodies

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Blood Groups

Name Number No.Ags ABO 001 2 Name Number No Ags

Rh 004 52 Dombrock 014 5 MNS 002 37 Colton 015 3 P 003 1 LW 016 3 Lutheran 005 19 Chido 017 9 Kell 006 21 Hh 018 1 Lewis 007 3 Kx 019 1 Duffy 008 6 Gerbich 020 7 Kidd 009 3 Cromer 021 10 Diego 010 2 Knops 022 5 Cartwright 011 2 Indian 023 2 Xg 012 1 OK 024 1 Scianna 013 3 Raph 025 1 JMH 026 1

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