ABO Blood GroupingABO Blood Grouping

IntroductionIntroductionJiwan PaudelJiwan PaudelB.Sc(ag) I year II semB.Sc(ag) I year II sem1633916339

ABO BasicsABO Basics

Blood group antigens are actually sugars attached Blood group antigens are actually sugars attached to the red blood cell. to the red blood cell.

Antigens are Antigens are ““builtbuilt”” onto the red cell. onto the red cell.

Individuals inherit a gene which codes for specific Individuals inherit a gene which codes for specific sugar(s) to be added to the red cell.sugar(s) to be added to the red cell.

The type of sugar added determines the blood The type of sugar added determines the blood group.group.

ABO Type Frequencies In ABO Type Frequencies In IndiaIndia

ABO Type Per Cent

O 38.2%

A 19.6%

B 40.8%

AB 8.8%

Antibody clinical Antibody clinical significancesignificance

Immunizations are frequently done to protect Immunizations are frequently done to protect us from disease.us from disease. Receive Hepatitis B immunization.Receive Hepatitis B immunization. Actual bits of hepatitis virus injected.Actual bits of hepatitis virus injected. Body recognizes as foreign and produces an immune Body recognizes as foreign and produces an immune

antibody.antibody. Subsequent exposure to real Hepatitis B virus will Subsequent exposure to real Hepatitis B virus will

result in destruction of the virus by immune result in destruction of the virus by immune antibodies.antibodies.

ABO antibodies are immune and will result in ABO antibodies are immune and will result in destroying incompatible cells which may result destroying incompatible cells which may result in the death of the recipient.in the death of the recipient.

InheritanceInheritance

Blood group antigens are Blood group antigens are ““codominantcodominant””, if the gene , if the gene is inherited, it will be expressed.is inherited, it will be expressed.

Some aberrant genotypes do occur but due to the Some aberrant genotypes do occur but due to the rarity will not be discussed.rarity will not be discussed.

Understanding of basic inheritance important.Understanding of basic inheritance important.

GeneticsGeneticsTwo genes inherited, one from each parent.Two genes inherited, one from each parent. Individual who is A or B may be homozygous or Individual who is A or B may be homozygous or

heterozygous for the antigen.heterozygous for the antigen.Heterozygous: AO or BOHeterozygous: AO or BOHomozygous: AA or BBHomozygous: AA or BBPhenotype is the actual expression of the Phenotype is the actual expression of the

genotype, ie, group Agenotype, ie, group AGenotype are the actual inherited genes which Genotype are the actual inherited genes which

can only be determined by family studies, ie, AO.can only be determined by family studies, ie, AO.

Example of Determining Example of Determining GenotypeGenotype

MomMom’’s phenotype is group A, genotype AOs phenotype is group A, genotype AO

DadDad’’s phenotype is group B, genotype BOs phenotype is group B, genotype BO

B O

A AB 25% AO 25% (Group A)

O BO 25% (Group B) OO 25% (Group O)

Group OGroup OApproximately 38.2% of the Approximately 38.2% of the

population is group O.population is group O.

No A or B antigens present, No A or B antigens present, think of as think of as ““00”” antigens present. antigens present.

These individuals form potent These individuals form potent anti-A and anti-B antibodies anti-A and anti-B antibodies which circulate in the blood which circulate in the blood plasma at all times.plasma at all times.

Group AGroup AApproximately 19.6% of Approximately 19.6% of

the population is group A.the population is group A.

No B antigens present.No B antigens present.

These individuals form These individuals form potent anti-B antibodies potent anti-B antibodies which circulate in the which circulate in the blood plasma at all times.blood plasma at all times.

Group BGroup BApproximately 40.8% of the Approximately 40.8% of the

population is group B.population is group B.

No A antigens present.No A antigens present.

These individuals form potent These individuals form potent anti-A antibodies which anti-A antibodies which circulate in the blood plasma circulate in the blood plasma at all times.at all times.

Group ABGroup ABApproximately 8.8% of Approximately 8.8% of

the population is group the population is group AB.AB.

Both A and B antigens Both A and B antigens present.present.

These individuals These individuals possess no ABO possess no ABO antibodies.antibodies.

HemolysisHemolysisIf an individual is transfused with an If an individual is transfused with an

incompatible blood group destruction of the red incompatible blood group destruction of the red blood cells will occur.blood cells will occur.

This may result in the death of the recipient.This may result in the death of the recipient.

SummarySummaryBlood Group Antigens on cell Antibodies in

plasmaTransfuse with

group

A A Anti-B A or O

B B Anti-A B or O

AB A and B none AB, A, B or O

O None Anti-A & B O

Thank youThank you