ASCP Immunohematology (Blood Banking) 2 — Questions and Answers
Question 1: Cryoprecipitate is the treatment of choice for which specific clotting factor deficiency?
- Factor X deficiency
- Hemophilia A (Factor VIII deficiency) (Correct answer)
- Factor V deficiency
- Vitamin K deficiency
Correct answer: Hemophilia A (Factor VIII deficiency)
Cryoprecipitate is enriched in Factor VIII, fibrinogen, von Willebrand factor, and Factor XIII, making it useful for hemophilia A and hypofibrinogenemia.
Question 2: Which blood group system is associated with the 'Bombay phenotype' (Oh) lacking the H antigen?
- ABO system
- Lewis system
- H system (FUT1 gene) (Correct answer)
- Kell system
Correct answer: H system (FUT1 gene)
The Bombay phenotype results from homozygous FUT1 mutation, preventing H antigen synthesis; these individuals have anti-H and react with all ABO groups.
Question 3: Transfusion-related acute lung injury (TRALI) is primarily caused by:
- ABO incompatibility
- Bacterial contamination of platelets
- Donor anti-HLA or anti-neutrophil antibodies reacting with recipient (Correct answer)
- Iron overload
Correct answer: Donor anti-HLA or anti-neutrophil antibodies reacting with recipient
TRALI occurs when donor antibodies (anti-HLA or anti-HNA) activate recipient neutrophils in the lungs within 6 hours of transfusion.
Question 4: Which RhIG (RhoGAM) dose is given at 28 weeks gestation for Rh prophylaxis?
- 50 µg (minidose)
- 300 µg (full dose) (Correct answer)
- 150 µg
- 600 µg
Correct answer: 300 µg (full dose)
The standard 300-µg dose of Rh immune globulin is given at 28 weeks and again within 72 hours postpartum to prevent Rh sensitization.
Question 5: Which test detects unexpected antibodies in a patient's serum before transfusion?
- ABO typing
- Rh typing
- Antibody screen (indirect antiglobulin test) (Correct answer)
- Direct antiglobulin test
Correct answer: Antibody screen (indirect antiglobulin test)
The antibody screen tests patient serum against reagent RBCs with known antigens to detect clinically significant alloantibodies.
Question 6: The Kleihauer-Betke test is used to:
- Identify blood group antibodies
- Detect fetal-maternal hemorrhage by quantifying fetal cells in maternal blood (Correct answer)
- Type HLA antigens
- Screen for hemolytic disease
Correct answer: Detect fetal-maternal hemorrhage by quantifying fetal cells in maternal blood
Acid elution in the Kleihauer-Betke test removes adult hemoglobin, leaving fetal cells staining pink to quantify fetomaternal hemorrhage.
ASCP Immunohematology (Blood Banking) 2
Cryoprecipitate is the treatment of choice for which specific clotting factor deficiency?