ABO Blood Group System - Exam 1 Questions and Answers Graded A

ABO Blood Group System - Exam 1 Questions and Answers Graded A What are the five blood types? A, B, AB, O, ? What are the genotypes for the four major ABO blood groups? A: AA, AO B: BB, AO AB: AB O: OO Describe forward typing. Patient blood of an unknown type is mixed with known sera. A positive result is agglutination. An example: If anti-A serum causes a positive reaction, and the anti-B serum has a negative reaction, then the cells only have the A antigen and the blood type is type A. Describe reverse typing. Patient serum of unknown type is mixed with known cells. Example: if A cells do not cause a reaction, and B cells do cause a reaction, then the patient serum contains anti-B, which means they do not have the B antigen and (going off of the forward being A type), are confirmed to be type A. What antibodies and antigens do type A people have? Anti-B A antigen What antibodies and antigens do type B people have? Anti-A B antigen What antibodies and antigens do type AB people have? A and B antigen No anti-A or anti-B What antibodies and antigens do type O people have? Anti-A and anti-B No A or B antigen Where do the antigens come from? The cells Where do the antibodies in known serum come from? Human or monoclonal (murine) <-- rat What is the auto control composed of? 1 drop 3% cell suspension and 2 drops serum, both from the patient What reaction grade should forward typing have? Reverse typing? 4+ for forward 3+/4+ for reverse. How is ABO inherited? Mendelian genetics: Alleles of the same gene at a given locus. Co-dominant What blood groups do not show dosage? A, B, AB, O ABO does not show dosage What is the H antigen? It is a string of sugars on the cell that are the base for the ABO blood groups. It controls the expression of the A and B gene. Explain how A and B are expressed (H gene) A and B replace a part of the H sugar with the A and B sugar. When the H gene is not modified the person is type O. What is the A sugar called? n-acetylgalactosamine What is the B sugar called? d-galactose Can you tell the difference between HH and Hh? No. What blood group has the most H? The least? O has the most AB has the least T or F: B is better at converting H than A False. A is better at converting H. A patient has type hh, which means they have no H antigen. What blood type are they? Bombay. What happens if you give type O blood to a Bombay? They will make anti-H because they lack the H antigen and O blood has the most H antigen. What does the Se gene do? Allows people to secrete soluble forms of the ABO antigens on the cells. Controlled by Se/Se. How do we test for secretor status? We look for the inhibition of agglutination. Soluble antigens will bind to the antibody and neutralize it before it can bind to the RBC What is the frequency of the four major blood groups? O: 45% A: 40% B: 11% AB: 4% What percentage of people secrete antigen? 80% What age are ABO antigens able to be detected? 5-6 weeks of gestation, but low quantity of antigen. At what age are adult levels of ABO present? 2-4 years. Are anti-A and anti-B present at birth? No. What blood group does Bombay blood resemble? What is the difference? They look like type O because they have anti-A and anti-B, but they can make anti-H if given O blood. Name the compatible cell types for the blood groups (not type specific) Type A: O cells Type B: O cells Type AB: A, B, O cells Type O: O cells Name the compatible plasma types for the blood groups (not type specific) Type A: AB plasma Type B: AB plasma Type AB: AB plasma Type O: A, B, AB plasma Why are red cells enzyme treated prior to gel agglutination based testing? Enzymes cleave proteins on the surface of the RBC which allow underlying antigens to become available. Antigens that are not being testing for can be destroyed and others enhanced.