BLOOD GROUP: BLOOD GROUP History: Karl Landsteiner: History : Karl Landsteiner Discovered the ABO Blood Group System in 1901 He and his five co-workers began mixing each others red cells and serum together and inadvertently performed the first forward and reverse ABO groupings http://www.nobelpreis.org/castellano/medizin/images/landsteiner.jpg Why is it important?: Why is it important? ABO compatibility between donor cell and patient serum is the essential foundation of pretransfusion testing It is the only system with expected antibodies Whether they are IgG or IgM, ABO antibodies can activate complement readily This means that incompatibilities can cause life threatening situations (transfusion reactions) ABO antigens:: ABO antigens: Biochemical & Genetic Considerations PowerPoint Presentation: ABO system based on + nce or – nce of 2 Ag (A, B) Ag = Agglutinogens Ab =Agglutinins Reaction b/w Ag and Ab =Agglutination LANDSTEINER’S LAW: LANDSTEINER’S LAW If an antigen is present on the surface of RBC, the corresponding antibody is absent in the Plasma. Conversely ,if an antigen is absent , the corresponding antibody is present. The law holds good for the ABO system but not for the Rh system. ABO and H Antigen Genetics: 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 Location: 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 ABO Antigen Genetics: 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 H Antigen: 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) RBC Precursor Structure: RBC Precursor Structure Glucose Galactose N-acetylglucosamine Galactose Precursor Substance (stays the same) RBC Formation of the H antigen: Formation of the H antigen Glucose Galactose N-acetylglucosamine Galactose H antigen RBC Fucose H antigen: 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 A and B Antigen: 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 Formation of the A antigen: Formation of the A antigen Glucose Galactose N-acetylglucosamine Galactose RBC Fucose N-acetylgalactosamine Formation of the B antigen: Formation of the B antigen Glucose Galactose N-acetylglucosamine Galactose RBC Fucose Galactose Genetics: 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 H antigen: H antigen Certain blood types possess more H antigen than others: O>A 2 >B>A 2 B>A 1 >A 1 B Greatest amount of H Least amount of H PowerPoint Presentation: Why do Group O individuals have more H antigen than the other groups? Group O individuals have no A or B genes to convert the H antigen to A or B antigens….that means more H antigen sites What are blood types?: What are blood types? http://learn.genetics.utah.edu/units/basics/blood/types.cfm There are 3 alleles or genes for blood type: A, B, & O. Since we have 2 genes, there are 6 possible combinations. Blood Types AA or AO = Type A BB or BO = Type B OO = Type O AB = Type AB PowerPoint Presentation: How common is your blood type? 46.1% 38.8% 11.1% 3.9% Blood Types…: Blood Types… Blood from the donor to the recipient must be compatible. The problem occurs when the protein (antigen) outer layer of the RBC of a donor becomes coagulated or agglutinated (clumped) with the plasma proteins (agglutinins or antibodies) of the recipient. Blood Types…: Blood Types… There are four different types of blood A, B, AB, O They are determined by the protein (antigen) found on the RBC Type A, has protein (antigen) A on the RBC Type B, has protein (antigen) B on the RBC Type AB, has both protein (antigen) A and B on the RBC Type O, has neither protein (antigen) on the RBC PowerPoint Presentation: Type A would have B agglutinins (antibody) in the plasma. Type B would have A agglutinins (antibody) in the plasma. Type AB would not have agglutinins (antibody) in the plasma. Type O would have A and B agglutinins (antibody) in the plasma. ABO SYSTEM: ABO SYSTEM Blood group Antigen ( Agglutinogens ) Antibody (agglutinin) A a b B b a AB ab - O - ab PowerPoint Presentation: Type O is the universal donor, since it does not have antigens (proteins) on the surface of the RBC’s Type AB is the universal recipient, since it does not have agglutinins (antibody) in its plasma. Average Percents…: Average Percents… Type O—46% Type A—40% Type B—10% Type AB—4% BOMBAY BLOOD GROUP: BOMBAY BLOOD GROUP Rare type of blood group H antigen is absent. No antigen A ,or antigen B , no H antigen on the red cells. The Plasma contains anti-A ,anti-B ,and anti-H antibodies. As a result such person can receive blood only from a person having bombay blood type. INHERITANCE: INHERITANCE MOTHER PHENOTYPE A GENOTYPE AO GAMETES A O CHILDREN GENOTYPE AB AO PHENOTYPE AB A FATHER B BO B O OB OO B O Rh positive or negative: Rh positive or negative First found in a monkey Based on whether it has a antigen (protein) D Rh+ has the protein, Rh- does not have the protein. Pregnancy and blood type: Pregnancy and blood type Father--Rh+ blood Mother is Rh– Child could be Rh +. 1 st pregnancy--if the baby is rh +, then there are no complications. However, the mother will start to develop antibodies against the Rh factor Pregnancy: Pregnancy Second pregnancy, if the child is +, the mother’s antibodies can cross the placenta and start to attack the fetus’ blood cells, causing hemolysis. Hemolysis--breakdown of RBC and the release of hemoglobin into the plasma which can damage organs. This is called erythroblastosis fetalis,can cause severe anemia, jaundice possibly death. PowerPoint Presentation: Blood Transfusions A blood transfusion is a procedure in which blood is given to a patient through an intravenous (IV) line in one of the blood vessels. Blood transfusions are done to replace blood lost during surgery or a serious injury. A transfusion also may be done if a person’s body can't make blood properly because of an illness. A B O AB Who can give you blood? People with TYPE O blood are called Universal Donors, because they can give blood to any blood type. People with TYPE AB blood are called Universal Recipients, because they can receive any blood type. Rh + Can receive + or - Rh - Can only receive - Universal Donor Universal Recipient BLOOD PRODUCTS AND SUBSTITUTES: BLOOD PRODUCTS AND SUBSTITUTES Packed RBC Platelet concentrate WBC concentrate Fresh frozen Plasma Freeze Dried Plasma Albumin Immunoglobulins Plasma substitutes CROSS MATCHING : CROSS MATCHING The red cells and the plasma of the donar and recipient blood are seprated by centrifugation. Major side cross match: donor red cell are then treated with recipient plasma. Minor side cross match: the donor plasma is tested against the red cells of the recipient.