Abo blood groups

BLOOD GROUPING IS IMPOTENT IN BLOOD BANKING .THIS PRESENTATION IS ON ABO BLOOD GROUPS

1. The Blood Group System s                                                                                            D r. Y ogendra V ijay Resident doctor SMS Medical college,Jaipur ( R ajasthan)

2. Blood Groups, Blood Typing and Blood Transfusions The discovery of blood groups                        Experiments with blood transfusions, the transfer of blood or blood components into a person's blood stream, have been carried out for hundreds of years. Many patients have died and it was not until 1901, when the Austrian Karl Landsteiner discovered human blood groups, that blood transfusions became safer. Mixing blood from two individuals can lead to blood clumping or agglutination. The clumped red cells can crack and cause toxic reactions. This can have fatal consequences. Karl Landsteiner discovered that blood clumping was an immunological reaction which occurs when the receiver of a blood transfusion has antibodies against the donor blood cells. Karl Landsteiner's work made it possible to determine blood types and thus paved the way for blood transfusions to be carried out safely. For this discovery he was awarded the Nobel Prize in Physiology or Medicine in 1930.                                                                                                                                                      Blood group 0 If you belong to the blood group 0 (null), you have neither A or B antigens on the surface of your red blood cells but you have both A and B antibodies in your blood plasma.   The blood group you belong to depends on what you have inherited from your parents.

3. There are more than 20 genetically determined blood group systems known today The AB0 and Rhesus (Rh) systems are the most important ones used for blood transfusions. Not all blood groups are compatible with each other. Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals.

4.                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. AB0 blood grouping system

5.                                                                                                                                                         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.

6. The "A“ and "B" antigens are also produced by some other plants and microorganisms. Thus, individuals who do not recognize one or more of these antigens as "self" will produce antibodies against the plant or microbial antigen s. These antibodies will also react with human antigens of the same kind whether introduced via a blood transfusion or a tissue graft.

7. Significance of ABO Group ABO mismatched transfusions: Rare May be life threatening Can be caused by technical or clerical error Intravascular haemolysis More severe in group O patients 7

8. The ABO gene is autosomal (the gene is not on either sex chromosomes) The ABO gene locus   is located on the chromosome 9. Each person has two copies of genes coding for their ABO blood group (one maternal and one paternal in origin) A  and B blood groups are dominant over the O blood group A and B group genes are co-dominant ABO inheritance and genetics

9. Principles of Heredity Antigens and enzymes are genetically controlled Genes : responsible for transfer of hereditable material Genes are found on chromosomes , which are found in the nucleus of every cell Human Cells contain 46 chromosomes with the exception of the egg and sperm, which contain only 23. 23 of these chromosomes are inherited from mother 23 of these chromosomes are inherited from father

10. Genes Come in Pairs The position a gene occupies on a chromosome is called a locus . Genes for the same trait are located at the same locus on both the mother and the father’s chromosomes. Alternative forms of genes that influence a given characteristic are called alleles. Father: allele for brown eyes Mother: allele for blue eyes

11. 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

12. Phenotype V. Genotype Phenotype : individual’s outward characteristics Genotype : individual’s pair of allele genes together Example: Phenotype Genotype Type B Blood Could be BO or BB depending on parents

13. Important Parts for Forensic Science Red Blood Cells—because of their importance in blood typing Serum—because of its’ importance in carrying antibodies

14. 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

15. Location The presence or absence of the ABH antigens on the red blood cell membrane is controlled by the H gene The presence or absence of the ABH antigens in secretions is indirectly controlled by the Se gene

16. ABO Antigen Genetics H gene – H and h alleles (h is an amorph ) Se gene – Se and se alleles (se is an amorph) ABO genes – A, B and O alleles

17. 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 (proteins and lipids) is formed on an oligosaccharide chain (the basic structure)

18. RBC Precursor Structure Glucose Galactose N-acetylglucosamine Galactose Precursor Substance (stays the same) RBC

19. Formation of the H antigen Glucose Galactose N-acetylglucosamine Galactose H antigen RBC Fucose

20. 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 Immunodominant sugars are present at the terminal ends of the chains and confer the ABO antigen specificity

21. A and B Antigen The “ A ” gene codes for an enzyme (transferase) that adds N-acetylgalactosamine 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

22. Formation of the A antigen Glucose Galactose N-acetylglucosamine Galactose RBC Fucose N-acetylgalactosamine

23. Formation of the B antigen Glucose Galactose N-acetylglucosamine Galactose RBC Fucose Galactose

24. Genetics The H antigen is found on the RBC when you have the Hh or HH genotype, but NOT from the hh genotype The A antigen is found on the RBC when you have the Hh, HH, and A/A, A/O, or A/B genotypes The B antigen is found on the RBC when you have the Hh, HH, and B/B, B/O, or A/B genotypes

25. Group O Group A Many H antigen sites Fewer H antigen sites A A A A A Most of the H antigen sites in a Group A individual have been converted to the A antigen

26. ABO Antigens in Secretions Secretions include body fluids like plasma, saliva, synovial fluid, etc Blood Group Substances are soluble antigens (A, B, and H) that can be found in the secretions. This is controlled by the H and Se genes

27. Secretor Status The secretor gene consists of 2 alleles (Se and se) The Se gene is responsible for the expression of the H antigen on glycoprotein structures located in body secretions If the Se allele is inherited as SeSe or Sese, the person is called a “ secretor ” 80% of the population are secretors

28. Secretors Secretors express soluble forms of the H antigen in secretions that can then be converted to A or B antigens (by the transferases) Individuals who inherit the sese gene are called “nonsecretors” The se allele is an amorph (nothing expressed) sese individuals do not convert antigen precursors to H antigen and has neither soluble H antigen nor soluble A or B antigens in body fluids

29. Secretor Status Summary The Se gene codes for the presence of the H antigen in secretions, therefore the presence of A and/or B antigens in the secretions is contingent on the inheritance of the Se gene and the H gene Se gene (SeSe or Sese) H antigen in secretions A antigen B antigen se gene (sese) No antigens secreted in saliva or other body fluids and/or

30. 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 (fewer antigens are present on the RBC) Subgroups of A are more common than subgroups of B

31. Subgroups of A The 2 principle subgroups of A are: A 1 and A 2 Both react strongly with reagent anti-A To distinguish A 1 from A 2 red cells, the lectin Dolichos biflorus is used (anti-A 1 ) 80% of group A or AB individuals are subgroup A 1 20% are A 2 and A 2 B

32. A 2 Phenotype Why is the A 2 phenotype important? A 2 and A 2 B individuals may produce an anti-A 1 This may cause discrepancies when a crossmatch is done (incompatibility) What’s the difference between the A 1 and A 2 antigen? It’s quantitative The A 2 gene doesn’t convert the H to A very well The result is fewer A 2 antigen sites compared to the many A 1 antigen sites

33. A 1 and A 2 Subgroups* Anti-A antisera Anti-A 1 antisera Anti-H lectin ABO antibodies in serum # of antigen sites per RBC A 1 4+ 4+ Anti-B 900 x10 3 A 2 4+ 3+ Anti-B & anti-A 1 250 x10 3 *Adapted from Flynn, J. (1998). Essentials of Immunohematology

34. Other A subgroups There are other additional subgroups of A A int (intermediate), A 3 , A x , A m , A end , A el , A bantu A 3 red cells cause mixed field agglutination when polyclonal anti-A or anti-A,B is used Mixed field agglutination appears as small agglutinates with a background of unagglutinated RBCs They may contain anti-A 1

35. B Subgroups B subgroups occur less than A subgroups B subgroups are differentiated by the type of reaction with anti-B, anti-A,B, and anti-H B 3 , B x , B m , and B el

36. ABO Blood Group: ABO Antibodies

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

38. 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 (if you’re A, you don’t have anti-A) If you do NOT have a particular antigen on your red cells then it is possible (when exposed to foreign RBCs) to illicit an immune response that results in the production of the antibody specific for the missing antigen

39. ABO The ABO Blood Group System does NOT require the presence of a foreign red blood cell for the production of ABO antibodies ABO antibodies are “non-red blood cell stimulated” probably from environmental exposure and are referred to as “expected antibodies”

40. Anti-A 1 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 .

41. 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

42. 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)

43. ABO antibody facts Reactions phase: Room temperature Complement can be activated with ABO antibodies (mostly IgM, some IgG ) High titer: react strongly (4+)

44. 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 ( IgG crosses placenta) Reverse grouping (with serum) should not be performed on newborns or cord blood

45. Paternity Tests No blood group can be present in a child without being present in one of the parents Paternity tests can be resolved in this way unless disputed fathers have the same blood type Paternity tests can also be determined by using DNA testing

46. Blood as Evidence Blood typing not so useful anymore because of DNA technology Scientists can now characterize biological evidence by selecting regions of our DNA

47. AUTOSOMAL CHROMOSOME Dad Mom The alleles for Blood group are in the same place on the chromosome 9. However the genes have a different code giving the different blood group A B

48. This meant that if a person inherited one A group gene and one B group gene their red cells would possess both the A and B blood group antigens . These alleles were termed A ( which produced the A antigen ), B (which produced the B antigen) and O (which was "non functional"and produced no A or B antigen) What do c o-dominant gene s mean?

49. Parent Allele A B O A B O Possible Blood group Genotypes

50. Parent Allele A B O A AA AB AO B AB BB BO O AO BO OO Possible Blood group Genotypes

51. 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 and B Neither AB O Neither Anti-A and anti-B OO

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

53. METHODS OF ABO BLOOD GROUPING 1.SLIDE METHOD 2.TUBE METHOD 3.GEL SYSTEM 4.MICROPLATE TECHNIQUE 5.GLASS MICROBEAD METHOD 6.GALILEO METHOD

54. Several methods for testing the ABO group of an individual exist. The most common method is: Serology: This is a direct detection of the ABO antigens. It is the main method used in blood transfusion centres and hospital blood banks. This form of testing involves two components: a) Antibodies that are specific at detecting a particular ABO antigen on RBCs.           b) Cells that are of a known ABO group that are agglutinated by the naturally occurring antibodies in the person's serum.

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

56. Blood Group Antigens Antibodies Can give blood to Can receive blood from AB A B O

57. Blood Group Antigens Antibodies Can give blood to Can receive blood from AB A and B None AB AB, A, B, O A A B A and AB A and O B B A B and AB B and O O None A and B AB, A, B, O O