1. Blood Groups/Types

2. Blood Group Terms Antigens: chemical structures imparting specific properties to the surface of the RBC Antibodies: protein substance developed in response to foreign body substances

3. Blood Group Systems Detected on the basis of specific reaction with corresponding antibody (either agglutination, lysis, or hemolysis) as a result of the presence or absence of the blood protein antigens on the RBC surface Inherited according to Mendelian laws Fully formed either at birth or in early postnatal life & persist throughout life

4. ABO System Discovered by Landsteiner in 1900 Prior to discovery, blood transfusions were hit or miss Type A, Type B, Type AB, & Type O

5. Type A 41% of population Has A antigens on the RBC surface Has anti-B antibodies in the plasma Genotypes AA & AO = Phenotype A

6. Type B 10% of population Has B antigens on the RBC surface Has anti-A antibodies in the plasma Genotype BB & BO = Phenotype B

7. Type AB 4 % of population Has A & B antigens on the RBC surface Has NO antibodies in the plasma Universal Recipient: can receive Type A, Type B, Type AB, or Type O blood  NO antibodies in plasma to react with antigens Genotypes: AB = Phenotype AB

8. Type O 45% of population Has NO antigens on RBC surface Has anti-A & anti-B antibodies in the plasma Universal Donor: can be given to any blood type  no antigens on the RBCs Genotype OO = Phenotype O

9. Rh System Discovered by Landsteiner & Wiener in 1937 Discovered in the Rhesus monkey Rh is an antigen on the RBC surface

10. Rh + has the antigens on the RBC (85% of population) Rh – does NOT have the Rh antigens Rh + can accept Rh + or Rh – blood Rh – can accept ONLY Rh - blood

11. Rh Incompatibility When Rh– person receives Rh+ blood in a transfusion  person develops antibodies against the Rh+ factor Clinical problem if second transfusion of Rh+ blood given  Rh antibodies will clump with the Rh antigens S & S of transfusion reaction: chills, fever, rash, itching, SOB, nausea, nephralgia, hematuria, shock & death

12. Erythroblastosis fetalis Rh– mother and Rh+ father  Rh+ child 1 st pregnancy Mother develops antibodies to baby’s Rh+ antigens 2 nd pregnancy with Rh+ child  mother’s anti-Rh antibodies attack unborn child’s RBCs Prevention: shot of Rhogam shortly after birth of first Rh+ baby to block development of antibodies

13. Erythroblastosis fetalis Antigen-antibody reaction due to mixing of Rh+ blood of fetus with Rh- blood of mother during 2 nd Rh+ pregnancy Prevented with shot of Rhogam at birth of 1 st Rh+ baby