Blood Groups for Students yesyesyes.pptx

Blood Groups

1. Blood Groups Dr. L.S. Ojulari (MB;BS Ph.D.) Faculty of Basic Medical Sciences College of Health Sciences University of Ilorin

2. Introduction There are more than 20 genetically determined blood group systems The AB0 and Rhesus (Rh) systems used for blood transfusions. Not all blood groups are compatible with each other -blood clumping or agglutination

3. Antigen any substance to which the immune system can respond. components of the bacterial cell wall self-antigens

4. Red Blood Cell Antigen Multiple antigens on the red blood cell blood transfusions may trigger immune reactions.

5. Antigens Blood group antigens- sugars or proteins attached to components in the red blood cell membrane. antigens of the ABO blood group are sugars. -produced by a series of reactions in which enzymes catalyze the transfer of sugar units. -DNA determines the type of enzymes they have

6. ABO inheritance and genetics • The ABO gene is autosomal • The ABO gene locus is located on the chromosome 9. • Each person has two copies of genes coding for their ABO blood group • A and B blood groups are dominant over the O blood group • A and B group genes are co-dominant ABO inheritance and genetics

7. Blood Types are Genetic A and B Blood Types are Dominant Dominant: Characteristic is shown Blood Type O is Recessive Recessive: Characteristic is hidden Recessive characteristics only appear when both alleles are recessive Homozygous recessive OO

8. ABO and H Antigen Genetics Genes at three separate loci control the occurrence and location of ABO antigens The presence or absence of the A, B, and H antigens is controlled by the H and ABO genes

9. H Antigen The H gene codes for an enzyme that adds the sugar fucose to the terminal sugar of a precursor substance (PS) The precursor substance is formed on an oligosaccharide chain

10. H antigen The H antigen is the foundation upon which A and B antigens are built A and B genes code for enzymes that add an immunodominant sugar to the H antigen

11. A and B Antigen The “ A ” gene codes for an enzyme that adds Nacetylgalactosamine to the terminal sugar of the H antigen -N- acetylgalactosaminyltransferase The “ B ” gene codes for an enzyme that adds D-galactose to the terminal sugar of the H antigen D-galactosyltransferase

12. ABO Subgroups ABO subgroups differ in the amount of antigen present on the red blood cell membrane Subgroups have less antigen Subgroups are the result of less effective enzymes. They are not as efficient in converting H antigens to A or B antigens Subgroups of A are more common than subgroups of B

13. Subgroups of A and B The 2 principle subgroups of A are: A 1 and A 2 - Dolichos biflorus (anti-A 1 ) B subgroups occur less than A subgroups -B 3 , Bx, Bm, and Bel

14. Landsteiner’s Rule : Normal, Healthy individuals possess ABO antibodies to the ABO antigen absent from their RBCs

15. Landsteiner’s Rule : Blood group A If you belong to the blood group A, you have A antigens on the surface of your RBCs and B antibodies in your blood plasma. Blood group B If you belong to the blood group B, you have B antigens on the surface of your RBCs and A antibodies in your blood plasma.

16. Landsteiner’s Rule : Blood group AB If you belong to the blood group AB, you have both A and B antigens on the surface of your RBCs and no A or B antibodies at all in your blood plasma. Blood group O If you belong to the blood group O, you have neither A or B antigens on the surface of your RBCs but you have both A and B antibodies in your blood plasma.

17. Blood Group Systems Most blood group systems (ABO and others) are made up of: An antigen on a red cell and the absence of it’s corresponding antibody in the serum Absence of a particular antigen on your red cells – antibody production to absent antigen

18. ABO The ABO Blood Group System does NOT require the presence of a foreign red blood cell for the production of ABO antibodies

19. Anti-A1 Group O and B individuals contain anti-A in their serum However, the anti-A can be separated into different components: anti-A and anti-A 1 Anti-A 1 only agglutinates the A 1 antigen, not the A 2 antigen There is no anti-A 2 .

20. Anti-A, B Found in the serum of group O individuals Reacts with A, B, and AB cells Predominately IgG, with small portions being IgM Anti-A, B is one antibody, it is not a mixture of anti-A and anti-B antibodies

21. ABO antibodies IgM is the predominant antibody in Group A and Group B individuals Anti-A Anti-B IgG (with some IgM) is the predominant antibody in Group O individuals Anti-A,B (with some anti-A and anti-B)

22. ABO Antibodies Usually present within the first 3-6 months of life Stable by ages 5-6 years Decline in older age Newborns may passively acquire maternal antibodies

23. Co-dominant genes inheritance one A group gene and one B group gene- red cells would possess both the A and B blood group antigens .

24. Possible Blood Group Genotypes Parent Allele A B O A AA AB AO B AB BB BO O OA OB OO

25. The ABO blood groups The most important in assuring a safe blood transfusion. The table shows the four ABO phenotypes ("blood groups") present in the human population and the genotypes that give rise to them. Blood Group Antigens on RBCs Antibodies in Serum Genotypes A A Anti-B AA or AO B B Anti-A BB or BO AB A & B Neither AB O Neither Anti-A & Anti-B OO

26. Laboratory Determination of the ABO System The ABO Blood Group System

27. METHODS OF ABO BLOOD GROUPING SLIDE METHOD TUBE METHOD GEL SYSTEM MICROPLATE TECHNIQUE GLASS MICROBEAD METHOD GALILEO METHOD

28. Serology The most common method is: Serology: This is a direct detection of the ABO antigens. This form of testing involves two components: Antibodies that are specific at detecting a particular ABO antigen on RBCs . Cells that are of a known ABO group that are agglutinated by the naturally occurring antibodies in the person's serum.

29. Illustration of the forward and reverse grouping reaction patterns of the ABO groups using a blood group tile

30. Blood Group Antigens Antibodies Can give blood to (Donor) Can receive blood from (Recipient) AB A & B None AB All A A B A & AB A & O B B A B & AB B & O O None A & B All O