Harr Medical Laboratory Science//Harr ASCP
Review Harr-Immunology Exam Question And
Answers Verified 100% Correct
What sample is best for detecting complement-dependent antibodies? -
ANSWER
Serum stored at 4°C for no longer than 48 hours
Which antibody would not be detected by group O screening cells? - ANSWER Anti-A1
Refer to Panel 1. Which antibody is most likely implicated? - ANSWER Anti-Jkb
Refer to Panel 2. Which antibody specificity is most likely present? - ANSWER Anti-C
and anti-K
On Panel 2, which of the following antibodies could not be ruled out? - ANSWER AntiC
On Panel 2, which cells are homozygous for C? - ANSWER 1, 2, 9
A 77-year-old female is admitted to a community hospital after a cardiac arrest. History
includes an abdominal aortic aneurysm 2 years ago in which she received 6 units of
packed cells. Her blood type is A positive and antibody screen is positive at AHG phase
in screening cells II and III. A panel is performed using LISS. Referring to panel 3, which
antibodies are likely implicated? - ANSWER E and c
What observation is apparent with one of the antibodies present on Panel 3? -
ANSWER One antibody is only reacting with homozygous cells
SITUATION: An emergency trauma patient requires transfusion. Six units of blood are
ordered stat. There is no time to draw a patient sample. O-negative blood is released.
When will compatibility testing be performed? - ANSWER Compatibility testing will be
performed when a patient sample is available
How would autoantibodies affect compatibility testing? - ANSWER ABO, Rh, antibody
screen, and crossmatch may show abnormal results
An antibody screen is reactive at IAT phase of testing using a three-cell screen and the
autocontrol is negative. What is a possible explanation for these results? - ANSWER
High-frequency alloantibody or a mixture of alloantibodies
What does a minor crossmatch consist of? - ANSWER Recipient red cells and donor
,plasma
Can crossmatching be performed on October 14th using a patient sample drawn on
October 12th? - ANSWER Yes, a new sample would not be needed
A type and screen was performed on a 32-year-old woman, and the patient was typed
as AB negative. There are no AB-negative units in the blood bank. What should be
done? - ANSWER Check inventory of A-, B-, and O-negative units
What ABO types may donate to any other ABO type? - ANSWER O negative
What type(s) of red cells is (are) acceptable to transfuse to an O-negative patient? -
ANSWER O negative
A technologist removed 4 units of blood from the blood bank refrigerator and placed
them on the counter. A clerk was waiting to take the units for transfusion. As she
checked the paperwork, she noticed that one of the units was leaking onto the counter.
What should she do? - ANSWER Discard the unit
A donor was found to contain anti-K using pilot tubes from the collection procedure.
How would this affect the compatibility test? - ANSWER Compatibility testing would
not be affected
Which of the following is not a requirement for the electronic crossmatch? -
ANSWER
There are concordant results of at least one determination of the recipient's ABO type
on file
A patient showed positive results with screening cells and 4 donor units. The patient
autocontrol was negative. What is the most likely antibody? - ANSWER Anti-k
Screening cells and major crossmatch are positive on IS only, and the autocontrol is
negative. Identify the problem. - ANSWER Cold alloantibody
Six units are crossmatched. Five units are compatible, one unit is incompatible, and the
recipient's antibody screen is negative. Identify the problem: - ANSWER Donor unit
may have a positive DAT
An incompatible donor unit is found to have a positive DAT. What should be done with
the donor unit? - ANSWER Discard the unit
Screening cells, major crossmatch, and patient autocontrol are positive in all phases.
Identify the problem. - ANSWER Abnormal protein or nonspecific autoantibody
,A panel study has revealed the presence of patient alloantibodies. What is the first step
in a major crossmatch? - ANSWER Antigen type patient cells and any donor cells to
be crossmatched
What is the disposition of a donor red blood cell unit that contains an antibody? -
ANSWER The unit may be labeled indicating it contains antibody and released into
inventory
Given a situation where screening cells, major crossmatch, autocontrol, and DAT (anti-
IgG) are all positive, what procedure should be performed next? - ANSWER Elution
followed by a cell panel on the eluate
A major crossmatch and screening cells are 2+ at IS, 1+ at 37°C, and negative at the
IAT phase. Identify the most likely problem. - ANSWER Cold alloantibody
What corrective action should be taken when rouleaux causes positive test results? -
ANSWER Perform a saline replacement technique
All of the following are reasons for performing an adsorption, except: -
ANSWER
Identification of antibodies causing a positive DAT
How long must a recipient sample be kept in the blood bank following compatibility
testing? - ANSWER 7 days
What is the crossmatching protocol for platelets and/or plasma? - ANSWER No testing
is required
What are the compatibility requirements for an autologous unit? - ANSWER ABO and
Rh typing
A patient types as AB positive. Two units of blood have been ordered by the physician.
Currently, the inventory shows no AB units, 10 A-positive units, 1 A-negative unit, 5 B-
positive units, and 20 O-positive units. Which should be set up for the major
crossmatch? - ANSWER A-positive units
Which of the following comprises an abbreviated crossmatch? - ANSWER ABO, Rh,
antibody screen, IS crossmatch
When may an IS crossmatch be performed? - ANSWER When there is no history of
antibodies and the current antibody screen is negative
, A patient had a transfusion reaction to packed red blood cells. The medical laboratory
scientist began the laboratory investigation of the transfusion reaction by assembling
pre- and post-transfusion specimens and all paperwork and computer printouts. What
should he do next? - ANSWER Check for a clerical error(s)
What is the pathophysiological cause surrounding anaphylactic and anaphylactoid
reactions? - ANSWER Patient is deficient in IgA and develops IgA antibodies via
sensitization from transfusion orpregnancy
A patient has a hemolytic reaction to blood transfused 8 days ago. What is the most
likely cause? - ANSWER Delayed immunologic, probably due to an antibody such as
anti-Jka
What may be found in the serum of a person who is exhibiting signs of TRALI
(transfusion-related acute lung injury)? - ANSWER Antileukocyte antibody
Which type of transfusion reaction occurs in about 1% of all transfusions, results in a
temperature rise of 1°C or higher, is associated with blood component transfusion, and
is not related to the patient's medical condition? - ANSWER Febrile nonhemolytic
reaction
What would be the result of group A blood given to an O patient? -
ANSWER
Immediate hemolytic transfusion reaction
Patient DB received 2 units of group A-positive red cells 2 days ago. Two days later, he
developed a fever and appeared jaundiced. His blood type was A positive. A transfusion
reaction workup was ordered. There were no clerical errors detected. A post-transfusion
specimen was collected and a DAT performed. The DAT was positive with monospecific
anti-IgG. The plasma was also hemolyzed. An antibody screen and panel studies
revealed the presence of anti-Jkb(post specimen). The antibody screen on the
pretransfusion specimen was negative. Which of the following explain the positive DAT?
- ANSWER The donor cells were likely positive for the Jkb antigen
All of the following are part of the preliminary evaluation of a transfusion reaction,
except: - ANSWER Panel on pre- and post-transfusion samples
A 68-year-old female diagnosed with neutropenia and inflammation of the left hand was
typed as A positive, and received 1 packed red blood cell unit. The antibody screen was
negative and crossmatch was compatible. During the transfusion, her pulse was 94,
and blood pressure rose from 114/59 to 132/64. Her temperature rose from 37.1°C
pretransfusion to 37.8°C 60 minutes after starting transfusion, then to 38.1°C upon
completion. A post-transfusion specimen yielded plasma that was neither hemolyzed
nor icteric, and a negative DAT. Post-transfusion urinalysis gave a 1+ blood and protein
Review Harr-Immunology Exam Question And
Answers Verified 100% Correct
What sample is best for detecting complement-dependent antibodies? -
ANSWER
Serum stored at 4°C for no longer than 48 hours
Which antibody would not be detected by group O screening cells? - ANSWER Anti-A1
Refer to Panel 1. Which antibody is most likely implicated? - ANSWER Anti-Jkb
Refer to Panel 2. Which antibody specificity is most likely present? - ANSWER Anti-C
and anti-K
On Panel 2, which of the following antibodies could not be ruled out? - ANSWER AntiC
On Panel 2, which cells are homozygous for C? - ANSWER 1, 2, 9
A 77-year-old female is admitted to a community hospital after a cardiac arrest. History
includes an abdominal aortic aneurysm 2 years ago in which she received 6 units of
packed cells. Her blood type is A positive and antibody screen is positive at AHG phase
in screening cells II and III. A panel is performed using LISS. Referring to panel 3, which
antibodies are likely implicated? - ANSWER E and c
What observation is apparent with one of the antibodies present on Panel 3? -
ANSWER One antibody is only reacting with homozygous cells
SITUATION: An emergency trauma patient requires transfusion. Six units of blood are
ordered stat. There is no time to draw a patient sample. O-negative blood is released.
When will compatibility testing be performed? - ANSWER Compatibility testing will be
performed when a patient sample is available
How would autoantibodies affect compatibility testing? - ANSWER ABO, Rh, antibody
screen, and crossmatch may show abnormal results
An antibody screen is reactive at IAT phase of testing using a three-cell screen and the
autocontrol is negative. What is a possible explanation for these results? - ANSWER
High-frequency alloantibody or a mixture of alloantibodies
What does a minor crossmatch consist of? - ANSWER Recipient red cells and donor
,plasma
Can crossmatching be performed on October 14th using a patient sample drawn on
October 12th? - ANSWER Yes, a new sample would not be needed
A type and screen was performed on a 32-year-old woman, and the patient was typed
as AB negative. There are no AB-negative units in the blood bank. What should be
done? - ANSWER Check inventory of A-, B-, and O-negative units
What ABO types may donate to any other ABO type? - ANSWER O negative
What type(s) of red cells is (are) acceptable to transfuse to an O-negative patient? -
ANSWER O negative
A technologist removed 4 units of blood from the blood bank refrigerator and placed
them on the counter. A clerk was waiting to take the units for transfusion. As she
checked the paperwork, she noticed that one of the units was leaking onto the counter.
What should she do? - ANSWER Discard the unit
A donor was found to contain anti-K using pilot tubes from the collection procedure.
How would this affect the compatibility test? - ANSWER Compatibility testing would
not be affected
Which of the following is not a requirement for the electronic crossmatch? -
ANSWER
There are concordant results of at least one determination of the recipient's ABO type
on file
A patient showed positive results with screening cells and 4 donor units. The patient
autocontrol was negative. What is the most likely antibody? - ANSWER Anti-k
Screening cells and major crossmatch are positive on IS only, and the autocontrol is
negative. Identify the problem. - ANSWER Cold alloantibody
Six units are crossmatched. Five units are compatible, one unit is incompatible, and the
recipient's antibody screen is negative. Identify the problem: - ANSWER Donor unit
may have a positive DAT
An incompatible donor unit is found to have a positive DAT. What should be done with
the donor unit? - ANSWER Discard the unit
Screening cells, major crossmatch, and patient autocontrol are positive in all phases.
Identify the problem. - ANSWER Abnormal protein or nonspecific autoantibody
,A panel study has revealed the presence of patient alloantibodies. What is the first step
in a major crossmatch? - ANSWER Antigen type patient cells and any donor cells to
be crossmatched
What is the disposition of a donor red blood cell unit that contains an antibody? -
ANSWER The unit may be labeled indicating it contains antibody and released into
inventory
Given a situation where screening cells, major crossmatch, autocontrol, and DAT (anti-
IgG) are all positive, what procedure should be performed next? - ANSWER Elution
followed by a cell panel on the eluate
A major crossmatch and screening cells are 2+ at IS, 1+ at 37°C, and negative at the
IAT phase. Identify the most likely problem. - ANSWER Cold alloantibody
What corrective action should be taken when rouleaux causes positive test results? -
ANSWER Perform a saline replacement technique
All of the following are reasons for performing an adsorption, except: -
ANSWER
Identification of antibodies causing a positive DAT
How long must a recipient sample be kept in the blood bank following compatibility
testing? - ANSWER 7 days
What is the crossmatching protocol for platelets and/or plasma? - ANSWER No testing
is required
What are the compatibility requirements for an autologous unit? - ANSWER ABO and
Rh typing
A patient types as AB positive. Two units of blood have been ordered by the physician.
Currently, the inventory shows no AB units, 10 A-positive units, 1 A-negative unit, 5 B-
positive units, and 20 O-positive units. Which should be set up for the major
crossmatch? - ANSWER A-positive units
Which of the following comprises an abbreviated crossmatch? - ANSWER ABO, Rh,
antibody screen, IS crossmatch
When may an IS crossmatch be performed? - ANSWER When there is no history of
antibodies and the current antibody screen is negative
, A patient had a transfusion reaction to packed red blood cells. The medical laboratory
scientist began the laboratory investigation of the transfusion reaction by assembling
pre- and post-transfusion specimens and all paperwork and computer printouts. What
should he do next? - ANSWER Check for a clerical error(s)
What is the pathophysiological cause surrounding anaphylactic and anaphylactoid
reactions? - ANSWER Patient is deficient in IgA and develops IgA antibodies via
sensitization from transfusion orpregnancy
A patient has a hemolytic reaction to blood transfused 8 days ago. What is the most
likely cause? - ANSWER Delayed immunologic, probably due to an antibody such as
anti-Jka
What may be found in the serum of a person who is exhibiting signs of TRALI
(transfusion-related acute lung injury)? - ANSWER Antileukocyte antibody
Which type of transfusion reaction occurs in about 1% of all transfusions, results in a
temperature rise of 1°C or higher, is associated with blood component transfusion, and
is not related to the patient's medical condition? - ANSWER Febrile nonhemolytic
reaction
What would be the result of group A blood given to an O patient? -
ANSWER
Immediate hemolytic transfusion reaction
Patient DB received 2 units of group A-positive red cells 2 days ago. Two days later, he
developed a fever and appeared jaundiced. His blood type was A positive. A transfusion
reaction workup was ordered. There were no clerical errors detected. A post-transfusion
specimen was collected and a DAT performed. The DAT was positive with monospecific
anti-IgG. The plasma was also hemolyzed. An antibody screen and panel studies
revealed the presence of anti-Jkb(post specimen). The antibody screen on the
pretransfusion specimen was negative. Which of the following explain the positive DAT?
- ANSWER The donor cells were likely positive for the Jkb antigen
All of the following are part of the preliminary evaluation of a transfusion reaction,
except: - ANSWER Panel on pre- and post-transfusion samples
A 68-year-old female diagnosed with neutropenia and inflammation of the left hand was
typed as A positive, and received 1 packed red blood cell unit. The antibody screen was
negative and crossmatch was compatible. During the transfusion, her pulse was 94,
and blood pressure rose from 114/59 to 132/64. Her temperature rose from 37.1°C
pretransfusion to 37.8°C 60 minutes after starting transfusion, then to 38.1°C upon
completion. A post-transfusion specimen yielded plasma that was neither hemolyzed
nor icteric, and a negative DAT. Post-transfusion urinalysis gave a 1+ blood and protein
