ABO blood grouping in humans

1. ABO Blood GroupingABO Blood Grouping
IntroductionIntroduction
Jiwan PaudelJiwan Paudel
B.Sc(ag) I year II semB.Sc(ag) I year II sem
1633916339

2. ABO BasicsABO Basics
 Blood group antigens are actually sugars attachedBlood group antigens are actually sugars attached
to the red blood cell.to the red blood cell.
 Antigens areAntigens are ““builtbuilt”” onto the red cell.onto the red cell.
 Individuals inherit a gene which codes for specificIndividuals 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 bloodThe type of sugar added determines the blood
group.group.

3. ABO Type FrequenciesABO Type Frequencies
In IndiaIn India
ABO Type Per Cent
O 38.2%
A 19.6%
B 40.8%
AB 8.8%

4. Antibody clinicalAntibody clinical
significancesignificance
Immunizations are frequently done to protectImmunizations 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 immuneBody recognizes as foreign and produces an immune
antibody.antibody.
 Subsequent exposure to real Hepatitis B virus willSubsequent exposure to real Hepatitis B virus will
result in destruction of the virus by immuneresult in destruction of the virus by immune
antibodies.antibodies.
ABO antibodies are immune and will result inABO antibodies are immune and will result in
destroying incompatible cells which may resultdestroying incompatible cells which may result
in the death of the recipient.in the death of the recipient.

5. InheritanceInheritance
 Blood group antigens areBlood 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 theSome 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.

7. GeneticsGenetics
Two genes inherited, one from each parent.Two genes inherited, one from each parent.
Individual who is A or B may be homozygous orIndividual who is A or B may be homozygous or
heterozygous for the antigen.heterozygous for the antigen.
Heterozygous: AO or BOHeterozygous: AO or BO
Homozygous: AA or BBHomozygous: AA or BB
Phenotype is the actual expression of thePhenotype is the actual expression of the
genotype, ie, group Agenotype, ie, group A
Genotype are the actual inherited genes whichGenotype are the actual inherited genes which
can only be determined by family studies, ie, AO.can only be determined by family studies, ie, AO.

8. Example of DeterminingExample 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)

9. Group OGroup O
Approximately 38.2% of theApproximately 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 asthink of as ““00”” antigens present.antigens present.
These individuals form potentThese individuals form potent
anti-A and anti-B antibodiesanti-A and anti-B antibodies
which circulate in the bloodwhich circulate in the blood
plasma at all times.plasma at all times.

10. Group AGroup A
Approximately 19.6% ofApproximately 19.6% of
the population is group A.the population is group A.
No B antigens present.No B antigens present.
These individuals formThese individuals form
potent anti-B antibodiespotent anti-B antibodies
which circulate in thewhich circulate in the
blood plasma at all times.blood plasma at all times.

11. Group BGroup B
Approximately 40.8% of theApproximately 40.8% of the
population is group B.population is group B.
No A antigens present.No A antigens present.
These individuals form potentThese individuals form potent
anti-A antibodies whichanti-A antibodies which
circulate in the blood plasmacirculate in the blood plasma
at all times.at all times.

12. Group ABGroup AB
Approximately 8.8% ofApproximately 8.8% of
the population is groupthe population is group
AB.AB.
Both A and B antigensBoth A and B antigens
present.present.
These individualsThese individuals
possess no ABOpossess no ABO
antibodies.antibodies.

13. HemolysisHemolysis
If an individual is transfused with anIf an individual is transfused with an
incompatible blood group destruction of the redincompatible 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.

14. SummarySummary
Blood Group Antigens on cell Antibodies in
plasma
Transfuse 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

15. Thank youThank you