CLS 422 Clinical Immunohematology I Take Home Quiz Day Two ...

CLS 422 Clinical Immunohematology I
Take Home Quiz
Day Two
Working independently, select the best answer to the following questions. Submit your
answers via BlackBoard [Clinical Immunohematology I, Assignments, Student Lab,
Direct Antiglobulin Test Module, Quiz Two] before 8am of Day Three.
1. An antibody is considered clinically significant if it:
a. Forms without red blood cell stimulation
b. Occurs in over 90% of the population
c. Reacts at room temperature
d. Reduces red blood cell survival following transfusion
2. Of the following antibodies, which is most likely to cause a hemolytic transfusion
reaction?
a. Anti-i
b. Anti-Jk a
c. Anti-Le b
d. Anti-N
3. Which of the following antibodies is least likely to be classified as a cold
agglutinin?
a. Anti-M
b. Anti-D
c. Anti-Le a
d. Anti-I
4. Which of the following antibodies is most likely to react at the immediate spin
phase?
a. Anti-c
b. Anti-Fy b
c. Anti-M
d. Anti-S
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Student Lab Day Two Take Home Quiz

5. Which of the following antibodies typically shows enhanced reactivity with
enzyme treated red blood cells?
a. Anti-Fy a
b. Anti-Jk a
c. Anti-N
d. Anti-s
6. Which of the following could be classified as a low prevalence antigen?
a. I
b. Jk b
c. K
d. s
7. An anti-Jk a that is showing dosage will react strongest with which of the
following cells?
a. Jk(a+b+)
b. Jk(a+b-)
c. Jk(a-b+)
d. Jk(a-b-)
8. The purpose of performing the antibody screen is to detect clinically significant
______________:
a. Alloantibodies
b. Autoantibodies
c. Expected ABO antibodies
d. Heterophile antibodies
9. Antibody screening cell sets are comprised of RBCs from which ABO group?
a. A
b. B
c. O
d. Any ABO group is acceptable
10. What phases of testing must be included in the antibody screen?
a. 37 o C & AHG
b. Immediate spin, 37 o C & AHG
c. Immediate spin, room temperature & check cells
d. Tube, gel, solid phase
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Student Lab Day Two Take Home Quiz

11. What is the advantage of lowering the zeta potential in the antibody screen
procedure?
a. Allows RBCs to draw closer together so agglutination can occur
b. Decreases the sensitivity of the test system
c. Eliminates detection of naturally occurring antibodies
d. Increases the possibility of detecting an IgM antibody
12. When performing the antibody screen by tube method, the cells must be washed
following incubation at least:
a. Once
b. 3 times
c. 5 times
d. 10 times
13. T F A wash step is not necessary when using the solid phase adherence
method for the antibody screen.
14. T F An excess of serum proteins may cause false positive results in the
immediate spin and 37C phases of the antibody screen.
15. When performing the antibody screen by tube method, you discover the heat
block is set at 35 o C. How would this affect your test?
a. No effect. Incubation in a heat block is not indicated in an indirect
antiglobulin test procedure.
b. No effect. 35 o C is within the proper temperature range for incubation.
c. Must incubate longer to compensate for the decreased temperature.
d. Invalidates test, as temperature is too low for IgG antibodies to react.
16. When performing the antibody screen by gel method, you discover the screen
cells are only in a 0.8% cell suspension. How would this affect your test?
a. Must add 2 additional drops of cells to correct the serum: cell ratio.
b. No effect. 0.8% is the correct cell suspension for the gel method.
c. Wash the screen cells and resuspend with saline to a 2-5% suspension
d. Will need to centrifuge an additional 10 minutes to ensure all screen cells
enter the gel.
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Student Lab Day Two Take Home Quiz

17. When performing the antibody screen using the gel technique, the following
pattern is obtained:
I II III
How would you report these results?
a. Inconclusive
b. Negative
c. Negative, positive, positive
d. Positive
e. Positive, negative, negative
18. What is the proper interpretation of these results?
IS 37 AHG CC
I 0 0 0 2+
II 0 0 0 0
III 0 0 0 2+
a. Inconclusive
b. Negative
c. Positive
19. Which test would be performed in order to detect in vivo sensitization of red
blood cells?
a. ABO/Rh
b. Antibody screen
c. DAT
d. Weak D test
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Student Lab Day Two Take Home Quiz

20. The main difference between the direct antiglobulin test (DAT) and the indirect
antiglobulin test (IAT) is:
a. Sensitization takes place in the test system in the indirect antiglobulin test
and in the body in the DAT.
b. Specimen for the DAT is either the patient’s cells or serum whereas the
IAT only uses the patient’s serum.
c. The IAT detects only IgG antibodies whereas the DAT detects IgG and
complement.
d. Use of enhancement reagents is required in the IAT but not in the DAT.
21. Which of the following specimens is the best to use for a direct antiglobulin test?
a. Clot tube with gel separator
b. Clot tube, no gel, stored overnight at 1-6C
c. EDTA
d. Any plasma specimen will work equally well.
22. When investigating a positive DAT, it is important to get an accurate patient
history which includes: (More than one correct answer)
a. ABO & Rh
b. Diagnosis
c. Medications
d. Transfusions
23. In a hemolytic transfusion reaction, the patient has:
a. An allergy to a protein in the donor plasma.
b. Bacteria in the blood stream, due to contamination of donor blood.
c. An antibody directed against antigens on the donor’s leukocytes.
d. An antibody directed against antigens on the donor’s red blood cells.
24. In Hemolytic Disease of the Fetus and Newborn (HDFN), a positive DAT
indicates that the:
a. Infant’s RBCs are coated with maternal antibody.
b. Mother’s RBCs are coated with fetal antibody.
c. Infant’s RBCs are coated with paternal antibody.
d. Mother’s RBCs are in the infant’s circulation.
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Student Lab Day Two Take Home Quiz

25. Following a negative DAT, check cells are added to the reaction tube. A negative
reaction with check cells indicates results are:
a. Invalid. Additional AHG reagent must be added.
b. Invalid. The red blood cells must be washed an additional 2 times.
c. Invalid. The test must be repeated completely.
d. Valid and may be reported.
26. Given these results, what is coating this patient’s RBCs?
Patient cells vs.: Polyspecific AHG 3+
Anti-IgG 3+
Anti-C3d 0
a. IgG
b. C3d
c. Both complement and IgG
d. Nothing – the DAT is negative
27. Which of the following tests would be adversely affected by a positive DAT?
a. ABO
b. Antibody screen
c. Rh (immediate spin phase using low protein reagent)
d. Weak D
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Student Lab Day Two Take Home Quiz