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Blood Groups/Types. 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. Blood Group Systems.
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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
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
ABO System • Discovered by Landsteiner in 1900 • Prior to discovery, blood transfusions were hit or miss • Type A, Type B, Type AB, & Type O
Type A • 41% of population • Has A antigens on the RBC surface • Has anti-B antibodies in the plasma • Genotypes AA & AO = Phenotype A
Type B • 10% of population • Has B antigens on the RBC surface • Has anti-A antibodies in the plasma • Genotype BB & BO = Phenotype B
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
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
Rh System • Discovered by Landsteiner & Wiener in 1937 • Discovered in the Rhesus monkey • Rh is an antigen on the RBC surface
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
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
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
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