2. Blood Groups

3. Multiple Blood Group Antigens
30 common antigens
More than 100 uncommon antigens
Most of them are weak
ABO system of antigens very strong
Rh system also very strong

4. The ABO System Discovered in 1901 by Dr. Karl Landsteiner
4 Main Phenotypes (A, B, AB, O)
ABO gene located on long arm of chromosome 9

5. ABO blood group system Two antigens (Agglutinogens)
Agglutinogen A
Agglutinogen B
Two antibodies (Agglutinins)
Agglutinin anti A or alpha (α ) antibody
Agglutinin anti B or beta (β) antibody

6. ABO Antibodies A and B substances are the most common
Antibodies produced to “non-self” antigen
Produced after first few months of life
A & B people have mainly IgM
O people have IgG
May fade in old age

7. ABO Antibodies

8. ABO antigens found on surface of the cell

9. ABO blood group system (Cont…)
Four major groups
Blood group A Agglutinogen A is present
Blood Group B Agglutinogen B is present
Blood group AB Both Agglutinogens A & B are present
Blood group O None of the agglutinogens are present

10. ABO Blood Groups A - A antigen only B - B antigen only
AB - Both A and B antigens
O - Neither antigen

11. ABO Blood Group

12. ABO Blood Group

13. ABO Blood Group

14. ABO Blood Group

15. ABO Blood Group

16. ABO Markers (antigen and antibodies)
Blood Group Markers
ABO Markers (antigen and antibodies)
Blood Type
Antigen
(blood group)
Antibody
% population A
Anti-B 40 B
Anti-A 10 AB
A & B
none 5 O
None
Anti-A & Anti-B 45

17. Antigens and antibodies of ABO blood Group system
Landsteiner’s Law
In ABO blood group system
When one antigen is present on the cell membrane of RBCs, antibody which can react with this antigen is always absent.
And when one antigen is absent in the cell membrane of RBCs, antibodies to this antigen are always present in the plasma.

18. Blood Group Identification
ABO Identification
A cells clump with anti-A
B cells clump with anti-B
AB cells clump with both
O cells do not clump

19. Genotypes of blood groups
Three genes: A, B & O
Two of these genes are present, one on each of the paired chromosomes
O gene is functionless and does not produce antigen O
Both A & B genes always express in the form of Agglutinogen A and Agglutinogen B respectively

20. Genotypes of blood groups (Cont…)
Six possible combinations of these genes called ‘Genotypes’ can result, i.e. AA, AO, BB, BO, AB & OO
Four blood groups
AA & AO will express as Blood Group A
BB & BO will express as Blood Group B
AB genotype will express as Blood Group AB
OO genotype will express as Blood Group O
Every human being belongs to one of these six genotypes and blood groups

21. ABO Genotypes and Phenotypes

22. Blood groups with their genotypes, antigens and antibodies
AGGLUTINOGEN
AGGLUTININ OO O
None
Anti A Anti B
OA or AA A
Anti B
OB or BB B
Anti A AB
A & B

23. Origin of agglutinins Gamma globulins (like all other antibodies)
Mostly IgM & IgG immunoglobulins
Level at birth is almost ZERO and titre gradually increases after exposure to respective antigen
Small amount of antigen A & B enter into the body via food and other routes & produce respective antibody if that antigen is absent on the cells.

24. Blood transfusion In blood transfusion
Antigens of the donor are important. They should not be given to a person who has antibodies against these antigens
The antibodies of the donor are NOT important
They are diluted in recipient's plasma
Or their concentration falls too low in storage

25. Blood transfusion
The antigens in the recipient’s RBC are not important
The antibodies in recipient’s plasma are important

26. Universal Donor and Recipient
Group O
Carries no A or B antigens
Packed and processed units have little antibody
Universal Recipient
Group AB
Patient has no anti-A or anti-B present
Cannot lyse any transfused cells
Beware: other antibodies may be present

27. Transfusion reactions
Mismatched transfusion→ Transfusion reaction
IgG is divalent
IgM is polyvalent
Reaction between
Antigen & antibodies
→ Agglutination

28. AGGLUTINATION
Donor antigens and recepient antibodies are important.
Mismatched blood causes a transfusion reaction.
RBCs of donor blood are agglutinated.
Agglutination of recipient’s blood does not occur because plasma portion of the donor blood immediately becomes diluted by all the plasma of the recipient.

29. The titer of infused agglutinins decrease.
On the other hand, small amount of blood infused cannot dilute recipient’s agglutinins so recipient’s antibodies can still agglutinate the mismatched donor cells.Eventually either
Immediate hemolysis by hemolysins(IgM antibodies)
Later hemolysis from phagocytosis of agglutinated cells.

30. Agglutination
14-34

31. Transfusion reactions
Hemolysin antibodies are responsible for immediate hemolysis

32. Transfusion reactions
Agglutination →Plugging of small blood vessels by clumps

33. Transmission of many disease
Jaundice
Renal shut down
Transmission of many disease
Hepatitis
AIDS
Infectious diseases

34. Hb ___bilirubin___excreted in bile by the liver
Hb ___bilirubin___excreted in bile by the liver. Increased bilirubin ____jaundice.
If liver function is normal, the bile pigment
will be excreted into the intestines by the liver bile.
Jaundice usually does not appear unless 400ml of blood is hemolyzed in less than a day.

35. Acute KIDNEY shut down:
1.An-Ab reaction___toxic substances from hemolyzing blood_____renal vasoconstriction.
2.Loss of circulating RBCs____circulatory shock.
3.Free Hb +haptoglobin__excess of Hb leaks through the glomerular membrane into the kidney tubules.----renal tubular blockage.______acute kidney shut down.

36. Choose the best response
Q.1. In ABO blood group system:
a)Blood group A has anti A antibodies.
b)Blood group B has anti A antibodies.
c)Blood group O has no antibodies.
d)Blood group AB has anti A and anti B antibodies.

37. Q 2.In blood transfusion reaction:
a)Blood of the donor can dilute recipient’s antibodies.
b)Agglutination of the recipient’s blood occurs.
c)RBC’s of the donor’s blood are agglutinated.
d)Antigens of the recipient’s blood are important.

38. Q. 3. Regarding antibodies in ABO blood group system:
a)These are of IgE type.
b)Mostly are of IgG and IgM type.
c)Level of antibodies are maximum at birth.
d)Titer gradually decreases after exposure to respective antigens.

39. Q.4 Regarding antigens of ABO blood group system
Blood group A has agglutinogen B on the cell membrane of RBCs.
Blood group B has agglutinogen A on the cell membrane of RBCs.
Blood group AB has agglutinogen A and B on the cell membrane of RBCs.
Blood group O has agglutinogen A and B on the cell membrane of RBCs.

40. Thank-you
Questions ??