Southwestern University PHINMA

College of Medical Technology

Immunohematology LECTURE
POST TEST week 6 (assignment)
Ab Detection and Identification + Other Minor Blood Groups $%
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Family Name:_________________First Name_____________________________Year & Section: _______________

Professor: □ Merlyn A. Baraclan-Orais, MScPI(IP), RN, RMT Date: ________________________

□ Diadem L. Cruz, MSc, RMT Student Number: _____________________
General Instruction. Use a blue-inked pen only. Write the best letter of your choice after the number
on your ½ lengthwise yellow pad. NO ERASURES ALLOWED! Once done attach your yellow pad on this
questionnaire, then submit to your respective mayors.

____ 1. All of the following antigens are found on reagent screening cells except:
a. D. c. C.
b. Jsa. d. Fyb. e. none of the choices

____ 2. Which of the following statements concerning acid eluates is false?

a. Citric acid is an example of an acid eluate
b. The pH is reduced to 3 or less to disrupt the antigen-antibody complex
c. The pH of the eluate remains at 3 before testing against a panel
d. None of the above

____ 3. What screening cells are used primarily for testing donor units for unexpected antibodies?
a. Pooled c. 3-vial
b. 2-vial d. 4-vial e. none of the choices

____ 4. When performing the elution procedure, the solution containing the recovered antibody is called:
a. neutralized serum. c. the eluate.
b. the buffer. d. absorbed serum. e. none of the choices

____ 5. What is the purpose of Coombs’ control cells?

a. To ensure that AHG tests with negative results are not false-negatives
b. To ensure that washing removed all unbound antibody
c. To ensure that AHG was not omitted or inactivated
d. All of the above
e. none of the above

____ 6. In what test might rouleaux cause an interference?

a. DAT c. Reverse ABO grouping
b. Forward ABO grouping d. Rh control e. none of the choices

____ 7. What is an elution?

a. A technique used to dissociate IgM antibodies from sensitized RBCs
b. A technique used to dissociate IgG antibodies from sensitized RBCs
c. A technique used to reduce the zeta potential enhancing antigen binding
d. None of the above
e. all of the above

____ 8. A patient with a warm autoantibody has a positive DAT. The antibody screen was negative, but the eluate reacted
uniformly with all normal cells and patient cells. Why was the antibody screen negative?
a. Reagent red blood cells were saturated with warm autoantibody from patient serum
b. No alloantibodies were present
c. The warm autoantibody has bound to patient RBCs in circulation
d. Polyspecific AHG was used instead of monospecific IgG
e. none of the choices

____ 9. The process of removing antibody from serum by combining a serum sample with appropriate red blood cells under
optimal conditions is called:
a. elution. c. enzyme treatment.
b. absorption. d. sensitization. e. none of the choices

____ 10. How does LISS enhance antibody detection in the antibody screen?
a. Increases the incubation times, which increases the sensitivity of the test
b. Increases the zeta potential, promoting agglutination of sensitized red blood cells
c. Increases the rate at which antibody binds to red blood cell antigens
d. None of the above
e. all of the above

____ 11. Which cells are employed to remove autoantibody from patient serum without removing any alloantibody from
serum?
a. Coombs’ control red blood cells c. Patient red blood cells
b. Screening red blood cells d. Panel red blood cells e. none of the choices

____ 12. What would be a realistic source of finding compatible units for a person with an antibody to a high-frequency
antigen?
a. Random donor units
b. A donor of similar ethnic background
c. Siblings
d. Apheresis donors
e. none of the above

____ 13. Why is it important to match the lot number on the panel sheet with the lot number on the panel cells?
a. The ABO group will change from lot to lot.
b. Pattern of reactions will change from lot to lot.
c. It is a requirement of the FDA.
d. All of the above
e. none of the choices

____ 14. Which of the following high-frequency antigens do not cause in vivo red blood cell destruction when complexed with
corresponding antibody?
a. k c. Cha
b. Jsb d. Lub e. none of the choices

____ 15. A person has developed an antibody to the LISS reagent. What test will not be affected by this circumstance?
a. Major ACT crossmatch c. DAT
b. IAT d. Antibody screen e. none of the choices

____ 16. Which of the following statements is correct concerning cold antibody screens?
a. Patient serum is incubated with group O adult and cord red blood cells at 4°C.
b. Patient serum is incubated with group O cord cells at 37°C.
c. Patient serum is incubated with check cells at 18°C.
d. Patient serum is incubated with group A cord cells at room temperature.
e. none of the choices

____ 17. Routine pre-transfusion testing consists of all of the following except:
a. ABO typing. c. an antibody screen.
b. Rh typing. d. a DAT. e. none of the choices

____ 18. A positive autocontrol in antibody detection procedures is usually indicative of:
a. inadequate washing. c. positive IAT.
b. positive DAT. d. none of the choices e. all of the choices

____ 19. In interpreting an antibody screen, which of the following questions might be asked to decipher the class of antibody?
a. Is the autologous control positive or negative?
b. Is hemolysis present?
c. In what phase did the reaction occur?
d. Is rouleaux present?
e. none of the choices

____ 20. Why is an enzyme treatment used in antibody identification?

a. Enzymes aid in the dissociation of antibody from antigen in a positive DAT.
b. Enzymes aid in the separation and identification of multiple antibodies.
c. Enzymes aid in the absorption of autoantibody from patient serum.
d. Enzymes aid in the separation and identification of multiple antibodies and the absorption of autoantibody from patient
serum.
e. none of the choices

____ 21. Which of the following is a mechanism of an elution procedure?

a. Disruption of structural complementarity of antigen and antibody
b. Enhancement of structural complementarity of antigen and antibody
c. Exchange of one immunoglobulin class for another
d. Denaturation of membrane epitopes by chemical means
e. none of the choices above

____ 22. Neutralization of antibody is applicable to all of the following blood groups except:
a. Lewis. c. P1.
b. Rh. d. Chido. e. none of the choices

____ 23. What determines if a red blood cell antibody is clinically significant?
a. Class of antibody (IgG or IgM)
b. Shortened red blood cell survival
c. Shortened white blood cell survival
d. Shortened platelet survival
e. all of the choices

____ 24. Why are screening cells group O?

a. To prevent interference with anti-A and anti-B in patient serum
b. To prevent interference with A and B antigens on patient cells
c. Because group O cells are easier to acquire in random populations
d. Because group O cells contain antigens to clinically significant antibodies
e. none of the choices

____ 25. Cold-reactive autoantibodies can be selectively removed from patient serum by adsorption with autologous red blood
cells (RBCs). What other cells can be used?
a. Mouse RBCs c. Rabbit RBCs
b. Goat RBCs d. Donor RBCs e. none of the choices

____ 26. Why is rouleaux not usually found in the AHG phase of antibody screens?
a. High protein molecules are not reactive at 37°C.
b. Patient cells are washed away before adding AHG.
c. Patient serum is washed away before adding AHG.
d. None of the above
e. all of the above

____ 27. What is the most common use of adsorption?

a. Removal of plasma protein from patient serum
b. Removal of alloantibody from patient serum
c. Removal of autoantibody from patient serum
d. Removal of drug-induced antibody from patient serum
e. none of the choices

____ 28. What is a positive DAT?

a. In vitro sensitization of RBC with antigen
b. In vitro sensitization of RBC with antibody
c. In vivo sensitization of RBC with antibody
d. In vivo sensitization of RBC with antigen
e. none of the choices

____ 29. Which is the second phase of a hemagglutination reaction

a. blood cells are negative for the antigen.
b. Most persons are not antigenically stimulated to produce the antibody, because their red blood cells are positive for the Ag.
c. Anti-k has low avidity.
d. Most reagent cells are heterozygous for cellano.
e. none of the above

____ 39. What might a positive antibody screen and a negative auto control indicate?
a. An alloantibody is coating donor cells after a transfusion
b. An autoantibody has been detected
c. An alloantibody has been detected
d. Drug-induced antibody reacting with patient cells
e. none of the above

____ 40. When might you suspect multiple antibodies in a patient's serum?
a. Pattern of reactivity not fitting a single antibody
b. Variation in phase of reactivity
c. Variation in antibody reactivity strength
d. All of the above
e. none of the above

____ 41. In what circumstance would an alloadsorption be performed?

a. Warm autoantibody in serum c. Multiple antibodies in serum
b. HDN d. Hemolytic transfusion reaction e. none of the choices

____ 42. One drop of Coombs’ control cells was added to a negative antibody screen. No agglutination was observed after
centrifugation. What course of action is taken?
a. Report negative result b. Report inconclusive result
c. Repeat the test d. Add one more drop of check cells and re-centrifuge

____ 43. When are antibody titration studies warranted?

a. During a gastrointestinal bleed c. After bone marrow transplantation
b. During pregnancy d. During chemotherapy e. none of the choices

____ 44. What is the simplest way of reducing the interferences from benign cold autoantibodies in antibody screening
procedures?
a. Use polyspecific AHG c. Use prewarming techniques
b. Use monospecific IgG d. Use cold autoabsorption techniques e. none of the choices

____ 45. A 2-unit crossmatch was ordered on a patient in the emergency room. The patient's antibody screen was negative.
One unit was compatible and the other was incompatible at AHG. If the patient's antibody screen was negative and the donor
had no history of antibodies, what could be the reason for this reaction?
a. The patient's serum has an antibody to a low-frequency antigen not present on screening cells.
b. The donor has a positive DAT.
c. The patient's serum has an HTLA antibody.
d. Options A and B

____ 46. What test must be performed on a patient with a warm autoantibody in their serum before transfusing?
a. Prewarming c. Elution
b. Warm autoadsorption d. DAT e. none of the choices

____ 47. During an antibody ID, there was 1+ reaction at AHG with donor cells with the antigen profile Fya(+), Fyb(-). All other
donor cells on the panel were negative, including those that were Fya(+), Fyb(+). Given these results, what might be the
conclusion?
a. Single antibody (showing dosage)
b. Probably an antibody not represented on the antigen profile
c. An antibody to a high-frequency antigen
d. IgM antibody
e. all of the above

____ 48. What is the purpose of treating serum containing cold autoantibodies with dithiothreitol (DTT) or 2-mercaptoethanol
(2-ME)?
a. To denature IgG alloantibody and test serum for presence of IgM autoantibody
b. To denature IgM cold autoantibody and test serum for presence of IgM alloantibody
c. To denature IgM cold autoantibody and test serum for presence of IgG alloantibody
d. To denature IgM drug-induced antibody and test serum for presence of IgG alloantibody
e. none of the choices

____ 49. What is the first step in reading hemagglutination reactions?

a. Resuspension of red blood cells c. Grading agglutination
b. Checking supernatant for hemolysis d. None of the choices e. all of the choices

____ 50. How many units would you likely have to screen to find two compatible units for someone with the following
antibodies: anti-C, anti-Lea, anti-Jkb?
a. 10 c. 32
b. 15 d. 35 e. none of the choices

____ 51. Why might some blood banking facilities prefer the use of monospecific IgG over polyspecific antihuman globulin
(AHG) in their antibody screens?
a. Interference from naturally occurring warm antibodies in patient serum is reduced.
b. Interference from naturally occurring cold antibodies in patient serum is reduced.
c. There is more IgG in monospecific antisera than in polyspecific reagents.
d. Monospecific IgG has been standardized.
e. all of the above

____ 52. What is the purpose of saline washing in the antibody screen procedure?
a. Removal of bound IgG that would otherwise neutralize the AHG reagent
b. Removal of unbound IgG that would neutralize the AHG reagent
c. Stripping of the red blood cell membrane for alloantibody binding
d. Removal of unbound IgM that would neutralize AHG reagent
e. none of the choices

____ 53. Why can't autoadsorption be performed on a patient who was transfused 1 month before?
a. Only IgM antibody would be present at 1 month
b. Donor cells might adsorb out autoantibody in serum
c. Patient cells might adsorb out alloantibody in serum
d. Donor cells might adsorb out alloantibody in serum
e. none of the choices

____ 54. All of the following antigens are interacted by proteolytic enzymes except:
a. C. c. M.
b. Fya. d. S. e. none of the choices

____ 55. When should multiple antibodies be suspected in a positive antibody screen?
a. The auto-control was positive. b. Cells react at different phases and strengths.
c. Only the AHG phase is reactive. d. none of the choices e. all of the choices

____ 56. How is chloroquine diphosphate used in blood banking?

a. To accurately phenotype patient cells when IAT is positive
b. To enhance antigen-antibody binding in IAT
c. To accurately phenotype patient cells when the DAT is positive
d. To be used as an Rh control when DAT is positive
e. none of the choices

____ 57. Tests with which AHG reagents can determine if IgG, complement, or both are coating red blood cells?
a. Monospecific c. Standardized
b. Polyspecific d. Irradiated e. leukoreduced

____ 58. Which of the following is known as the "sensitization phase" in the antibody screen?
a. Immediate spin c. 37°C incubation
b. AHG d. None of the choices

____ 59. What is an antigen profile sheet?

a. An insert listing the antibodies present in each vial of screening cells
b. An insert listing the antigenic makeup of each vial of screening cells
c. A statistical comparison of 200 blood banks' results of antigenic reactions with various antisera
d. An insert listing the antigenic makeup of check cells
e. none of the choices

____ 60. What makes up an autologous control?

a. Patient serum and patient cells c. Patient cells and Rh control
b. Patient serum and screening cells d. None of the above e. none of the choices

____ 61. Why should only homozygous cells be used to rule out an antibody?
a. Homozygous cells carry a double dose of antibody.
b. Weakly reacting antibody may not react with heterozygous cells.
c. Strong reacting antibodies may not react with heterozygous cells.
d. All of the above
____ 62. In the autoabsorption procedure for the removal of cold autoagglutinins from serum, pre-treatment of the patient's
RBCs with which of the following reagents is helpful:
a. Ficin c. LISS
b. Phosphate buffered saline d. Albumin e. bromelain

____ 63. In which scenario can an antibody be ruled out?

a. Patient serum does not react with a cell known to carry the corresponding antigen
b. Patient serum does react with a cell known to carry the corresponding antigen
c. Patient cells do not react with a cell known to carry the corresponding antibody
d. Patient cells do react with a cell known to carry the corresponding antibody
e. none of the above

____ 64. What is done with a patient’s serum after an autoadsorption technique has been performed?
a. Alloantibodies are identified.
b. The serum is discarded.
c. Autoantibody is identified.
d. Alloantibodies are identified, and the serum can be used for compatibility testing.
e. none of the choices

____ 65. What is the final step in antibody identification?

a. Phenotype donor's RBC units for corresponding antigen
b. Phenotype patient's RBCs for corresponding antibody
c. Phenotype patient's RBCs for corresponding antigen
d. Phenotype RBC units for corresponding antibody
e. none of the choices

____ 66. A doctor has ordered 4 units of red blood cells for a patient with anti-E in his serum. How many units would have to be
screened to yield 4 E-negative units?
a. 10 c. 6
b. 15 d. 12 e. none of the choices

____ 67. How can neutralization aid in the identification of multiple antibodies?
a. Once antibody has been neutralized serum can be further tested in panel studies.
b. Neutralization inhibits all warm autoantibodies.
c. Neutralized serum can be used to phenotype patient cells.
d. All of the above

____ 68. What does a panel of reagent red blood cells consist of?
a. 1 to 5 group O red blood cell suspensions
b. 3-vial screening cells
c. 11 to 20 group O red blood cell suspensions
d. Pooled screening cells
e. all of the chocies

____ 69. If you suspect anti-C is present in a patient's serum, and anti-Fya still has to be ruled out using other reagent cells,
what would the phenotype of the rule out cell have to be?
a. Fy(a+), C–, Fy(b+) c. Fy(a+), C+, Fy(b-)
b. Fy(a+), C–, Fy(b-) d. Fy(a+), C+, Fy(b+) e. none of the choices

____ 70. Cells that have antibody attached to them but are still separated from one another are:
a. agglutinated. c. phagocytized.
b. sensitized. d. hemolyzed. e. none of the choices

____ 71. What is the advantage of having a 3-cell panel screen versus a 2-cell panel screen?
a. More cells in the homozygous state that show dosage
b. You can narrow down the specificity of the AB better.
c. You might detect more rare antibodies.
d. All of the above

____ 72. Name a disease in which your positive D control might be positive.
a. PCH c. Huntington's disease
b. Multiple myeloma d. Epstein-Barr virus e. all of the choices

____ 73. The electrical force that exists between red blood cells is:
a. called the zeta potential.
b. due to the net negative charge of the red blood cell membrane.
c. related to the voltage or potential that exists or at the surface of the RBC and the outer layer of the ionic cloud.
d. all of the above.

____ 74. Pseudoagglutination:

a. is frequently associated with alterations in serum proteins.
b. occurs when serum viscosity is increased.
c. can be confused with pan-agglutination.
d. all of the above.

____ 75. While performing an antibody screen, a test reaction is observed that is suspected to be rouleaux. A saline
replacement test is done, and the reaction remains. What is the best interpretation?
a. The original reaction was rouleaux and may be ignored.
b. The replacement test is invalid and should be repeated.
c. The original reaction was due to true agglutination.
d. The Ab screen is negative.
e. none of the choices

_____ 76. Of the Abs listed below, which does not fit with the others in terms of the optimal temperature of reactivity?
a. anti-P1 c. Anti- A1
b. Anti I d. anti- E e. none of the choices

____ 77. How are lipids dissociated from the red blood cell membrane for biochemical studies?
a. Increased pH c. Sodium dodecyl sulfate
b. Ion exchange d. Organic solvents e. none of the choices

____ 78. What abnormal blood cell morphology is associated with the McLeod phenotype?
a. Spherocytes c. Sickle cells
b. Ovalocytes d. Acanthocytes e. none of the choices

____ 79. Anti-I is found in association with what microorganism?

a. Mycoplasma pneumoniae c. Escherichia coli
b. Treponema pallidum d. Proteus vulgaris e. all of the choices

____ 80. Most blood group alleles are:

a. X-linked dominant. c. codominant.
b. X-linked recessive. d. none of the above.

____ 81. Serologic tests determine a person's:

a. genotype. c. phenotype.
b. haplotype. d. all of the above.

____ 82. ISBT nomenclature for the Xg System is

a. 002 c. 012
b. 006 d. 024 e. none of the choices

____ 83. Name the substance used to neutralize antibodies to P1.

a. Papain c. Dolichos biflorus
b. Hydatid cyst fluid d. Milk e. pepsin

____ 84. Antigens in the CH/RG blood group system are described as:
a. resistant to ficin treatment. b. antithetical partners.
c. well developed on cord cells. d. adsorbed onto the red blood cell membrane.

____ 85. Which antigen is expressed on C4B complement fragments?

a. Cha c. Yka
a
b. Kn d. Gya e. none of the choices

____ 86. A plasma inhibition study was performed on a patient whose serum sample reacted +/– on all panel cells at AHG.
Three sets of A, B, C tubes were set up according to the following scheme:
Tube A had 2 drops of patient serum and 1 drop of Ch(a+) Rg(a-) plasma.
Tube B had 2 drops of patient serum and 1 drop of Ch(a– Rg(a+) plasma.
Tube C had 2 drops of patient serum and 1 drop of Ch(a+) Rg(a+) plasma.
Screening cells were added in triplicate and incubated for 60 minutes at 37°C. The antiglobulin test was performed. All three A
tubes reacted at 2+, and the B and C tubes were negative. What antibody is indicated?
a. Anti-Cha c. Another alloantibody
b. Anti-Rga d. None of the above

____ 87. The Dia and Dib antigens are located on:
a. complement receptor one (CRI).
b. erythrocyte acetylcholinesterase.
c. the anion exchange molecule (AE-1).
d. channel-forming integral protein (CHIP).
e. none of the above

____ 88. Which of the following is true concerning Colton antibodies?

a. Encountered frequently
b. Destroyed by enzymes
c. React at immediate spin
d. Stimulated by red blood cell exposure
e. none of the above

____ 89. Anti-Sc3 will react with which Scianna phenotype?

a. Sc: -1, +2 c. Sc: +1, -2
b. Sc: +1, +2 d. All of the choices

____ 90. An antibody that reacts in the IAT phase of the antiglobulin test and whose antigen expression is depressed by the
In(Lu) gene is:
a. anti-Xga. c. anti-Inb.
b
b. anti-Yt . d. anti-Sc1. e. none of the choices

____ 91. The gene for which blood group antigen is located on the petite arm of the X chromosome?
a. Sc1 c. Coa
a
b. Xg d. Doa e. none of the choices

____ 92. The seven Gerbich antigens are located on:

a. glycophorins A and B. c. glycophorins A and D.
b. glycophorins C and D. d. glycophorins B and C. e. none of the choices

____ 93. The high-incidence Gya, Hy, and Joa antigens belong to which blood group system?
a. Wr c. DO
b. DI d. Sc e. none of the choices

____ 94. The mating of an Xg+ man with an Xg- woman would produce a son with what phenotype?
a. Xg(a+) c. All of the above
b. Xg(a-) d. None of the above

____ 95. The following is true regarding anti-Doa and anti-Dob.

a. They are destroyed by enzymes.
b. They are frequently naturally occurring.
c. They are known to cause HTRs.
d. They are known to cause clinical HDN.
e. all of the above

____ 96. What blood group antigens are involved in the regulation of complement because they are located on decoy
accelerating factor?
a. CO c. CROM
b. DO d. IN e. none of the choices

____ 97. Where might you expect anti-Ytb to react in antibody screening?
a. Immediate spin phase c. IAT phase
b. 37°C phase d. All of the above

____ 98. How does complement aid in the identification of alloantibodies masked by anti-Cha?
a. C4d in plasma will absorb anti-Cha. c. C3d in plasma will absorb anti-Cha.
b. C3b in serum will absorb anti-Cha. d. C4a in plasma will absorb anti-Cha. e. none of the choices

____ 99. Anti-Wrb has been frequently observed in patients:

a. with paroxysmal cold hemoglobinuria.
b. with warm autoimmune hemolytic anemia.
c. taking penicillin.
d. with paroxysmal nocturnal hemoglobinuria.
e. all of the above

____ 100. Bg antibodies are primarily directed toward antigenic determinants present on:
a. white blood cells. c. platelets.
b. red blood cells. d. meso cells. e. none of the choices

____ 101. The Wright blood group antigens belong to which blood group system?
a. Wr c. DO
b. DI d. SC e. none of the choices

____ 102. LW has a phenotypic relationship with the ________antigen.

a. D c. M
b. P1 d. Wra e. none of the choices

____ 103. Both anti-Dia and anti-Dib are known to:

a. cause severe HDN. c. occur as a result of red blood cell stimulation
b. bind complement. d. react at the 37°C and IgG phases. e. none of the choices

____ 104. What percentage of the female population is Xg(a+)?

a. 50% c. 89%
b. 66% d. 40% e. none of the choices

____ 105. What criteria must be met for an antigen to be assigned to a blood group system?
a. Must be a red blood cell antigen
b. Must be assigned to a unique chromosomal locus
c. Must be controlled by a single gene or two closely linked genes
d. All of the above

____ 106. The rarely encountered Scianna antibodies react in which phase of the antibody screen?
a. Immediate spin c. AHG
b. 37°C d. All of the above

____ 107. Which antibody is viewed to be clinically significant because of its association with HTR and HDN?
a. Anti-Bga c. Anti-Dib
b. Anti-Kna d. Anti-C e. none of the choices

____ 108. All of the following are inconsistent with Xga antibody characteristics except:
a. reactive at the IAT phase. c. resistant to enzymes.
b. IgM immunoglobulins. d. known to cause HTRs. e. none of the choices

____ 109. The Sc1 antigen occurs in approximately what percentage of the random population?
a. 100% c. 10%
b. 50% d. 35% e. none of the choices

____ 110. Which statement is true concerning the Cartwright antigens?

a. The Ytb antigen is a strong immunogen.
b. Cord blood tests as Yta negative.
c. The Yta is inherited as a dominant allele.
d. Ytb is a high-frequency antigen.
e. all of the above

____ 111. Which antigen in the high-incidence series (901) is usually IgM and occasionally causes hemolysis?
a. Vel c. Lan
b. JMH d. Sda e. none of the choices

____ 112. Disease associations have linked which Colton phenotype with monosomy-7?
a. Co(a+b-) c. Co(a-b+)
b. Co(a+b+) d. Co(a-b-) e. none of the choices

____ 113. _________ is an antigen in the high-prevalence series (901) that is found in saliva and urine. The corresponding
antibody typically reacts at the AHG phase and produces a characteristic refractile, mixed-field reaction.
a. Vel c. Lan
b. JMH d. Sda e. none of the choices
____ 114. Which antigen is useful as a genetic marker for Mongolian derivation and anthropologic studies?
a. Yta c. Xga
a
b. Di d. Doa e. none of the choices