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 1st pregnancy
Mother develops antibodies to baby’s Rh+ antigens
2nd 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 2nd Rh+ pregnancy
Prevented with shot of Rhogam at birth of 1st Rh+ baby