BB Exam 2 Questions
A group A, Rh(D)-positive patient is crossmatched with four units of RBCs. The antibody screen is positive at the AHG phase. Two of four units are also incompatible at the AHG phase of the crossmatch. What is the cause of the incompatibility? a. Donor alloantibody b. Donor RBCs have a positive DAT c. Recipient alloantibody d. Recipient autoantibody
c. Recipient alloantibody
List the three phases of the crossmatch and what antibody class are detected at each phase
Immediate Spin - IgM 37C - IgG AHG - IgG
What is the maximum amount of time a specimen may be used for pretransfusion testing?
72 hours
The mixed lymphocyte culture (MLC) is an older technique in the HLA laboratory used to determine: a. HLA-A antigens b. HLA-C antigens c. HLA antibody identification d. HLA-D antigens and compatibility
HLA-D antigens and compatibility
An antibody demonstrating dosage would mean that:
Homozygous cells were stronger
What is the common specificity of cold autoantibodies? a. I b. M c. P1 d. S
I
What is the first and second choices for when an alternate blood group must be transfused for blood group AB
1st = A, 2nd = O or B
What is the first and second choices for when an alternate blood group must be transfused for blood group A2B with anti-A1
1st = A2, 2nd = O or B
What is the first and second choices for when an alternate blood group must be transfused for blood group A
1st = O, 2nd = none (must be A or O)
What is the first and second choices for when an alternate blood group must be transfused for blood group B
1st = O, 2nd = none (must be B or O)
Anti-N is identified in a white patient who requires a blood transfusion. If 10 donor RBCs were tested, how many of these units would most likely be negative for the N antigen? a. 0 b. 3 c. 7 d. 10
3
Column agglutination is most commonly used to identify:
IgG antibodies
The antibody screen is negative, but a 2+ reaction is noted on one of the crossmatch tubes at the AHG phase. What additional test must be performed AND state the appropriate course of action for positive and negative results.
A DAT must be performed. If it is positive, return the unit to the blood provider. If it is negative, a panel study must be performed to determine the specificity of the antibody. If an antibody is identified, all units must be tested with the appropriate antiserum. Incompatible units as well as antigen positive units must be released and antigen negative units must be found and crossmatch with the patient. Then you must type the patient for the antigen to verify he/she is negative for the antigen.
Outline the procedure to follow when a unit appears compatible, but the antibody screen is positive.
A panel study must be done and the antibody specificity identified. The units must be tested for the antigen to which the antibody is directed (antigen typed). If any unit is antigen positive, even though it appears crossmatch compatible, it must be released (returned to regular stock, not to be used for this patient). Additional replacement units must be tested with antiserum until antigen negative units are found. These antigen negative units must be crossmatched with the patient before being considered compatible. Test the patient for the antigen to verify that he/she is antigen negative.
Compatibility testing includes a number of blood bank procedures performed prior to transfusion. List and briefly describe these four procedures.
A review of blood bank records for previous testing of the transfusion candidate. Previous ABO, D and antibody detection test results should be compared with current interpretations and any discrepancies resolved. Determination of ABO and D groups and examination for unexpected antibodies on each recipient sample received. Selection of ABO and D compatible donor units that have been tested in accordance with Standards and found acceptable for transfusion. Crossmatching tests between patient serum and donor red cells for evidence of serologic incompatibility.
Technological advancements in blood bank have resulted in testing methodologies like solid-phase technology. This technology can best be described as:
A test that uses microplate test wells with antigens in the bottom of the well and the patients plasma containing antibodies is incubated in the well.
Universal red blood cell recipient:
AB+
Universal plasma donor:
AB-
Which antibodies have Reactivity at AHG.
After addition of antiglobulin serum, almost all warm antibodies can be detected: Rh antibodies, anti-K, -Jk, -Fy, -S, etc.
What additional test(s) must be performed when a patient type is AB positive? Why?
An Rh control should be used to determine that the cells are actually D+ and not autoagglutinating.
Which antibodies reactivity are affected by enzymes.
Anti-Fy, -M, -N and -S may not be detected when enzymes are used. These antigens are denatured or destroyed by enzymes. This technique is very useful when multiple antibodies are present and one appears to have one of these specificities. Rh, Jk, Le, P, and I antibody reactions are enhanced by the enzyme procedures.
A multiple antibody problem was resolved using enzymes. One of the antibody reactions was eliminated after treatment. Which of the following antibodies was probably present?
Anti-Fya
Which antibodies cause Hemolysis.
Antibodies most often hemolyzing saline suspended cells are anti-Lea antibodies and Kidd
Which antibodies have Reactivity at 37 C.
Antibodies most often identified after incubation at 37 C are Rh, anti-K, -S and-s.
Which of the following cells expresses HLA class II antigens? a. B cells b. platelets c. erythrocytes d. T cells
B cells
A major crossmatch and screening cells are 2+ at the IS phase, 1+ at 37C, and negative at the IAT phase. Identify the most likely problem: Rouleaux Test error Cold alloantibody Combination of antibodies
Cold alloantibody
What is the immunoglobulin class of antibodies detected in the immediate-spin crossmatch?
IgM
Which of the following HLA antigens is not characterized as class I? a. C b. A c. DR d. B
DR
Which of the following reagents destroys the Kell system antigens? a. ficin b. albumin c. PEG d. DTT
DTT
What are the two components of the major crossmatch?
Donor red cells and recipient serum: A "major" crossmatch is used to assess the compatibility of a donor's red blood cells with the recipient's plasma. For example, if a donor is blood group A and a recipient is blood group B, blood bank personnel performing a major crossmatch prior to transfusion would mix the recipient's plasma/serum (containing anti-A antibodies) with the donor's group B red blood cells. Obviously, in this example, you would expect the result to be incompatible, and the blood would not be given (OK, don't send me e-mails about that scenario. That is obviously a make-believe case, and you wouldn't deliberately select group B red cells for a group A recipient!). TWO IMPORTANT NOTES: When blood bankers use the term "crossmatch" in pretransfusion testing, they really mean "major crossmatch" in virtually all situations The main function of the major crossmatch is to serve as the final check of ABO compatibility between donor and recipient before transfusion Obviously, if there is a "major" crossmatch, there must also be a "minor" crossmatchLinks to an external site., and there is (though we really don't use it). Multiple types of major crossmatches exist, including immediate spin, computer (electronic), and AHG versions.
Describe how a D-negative mother is exposed to the D antigen during the birth process.
During birth, fetal blood may enter the maternal circulation. If fetal cells contain D antigen, this may cause the mother to form an anti-D antibody to that antigen.
T/F? In the transfusion of plasma, the D phenotype is important for compatibility because Rh antigens are found only on the red cells.
False
Which of the following will result in malarial resistance? Fy(a-b+) Fy(a-b-) Fy(a+b+) Fy(a+b-)
Fy(a-b-)
Which phenotype is associated with a resistance to Plasmodium vivax? a. Fy(a−b−) b. Jk(a−b−) c. Le(a−b−) d. Lu(a−b−)
Fy(a-b-)
State the reason that the second choice for an AB individual is group O instead of group B.
Group B is uncommon and Group O usually has an abundant supply.
State the consequences that may occur if complete concentration and good techniques are not utilized while performing blood bank procedures.
Incorrect identification of specimens or materials or incorrect recording of results or interpretations cause false positives, false negatives and could threaten someone's life.
Which of the following blood group systems is associated with a depression of the antigens in chronic granulomatous disease? a. Duffy b. Kidd c. P d. Kell
Kell
All of the following are true regarding Kell antibodies except: Kell antibodes are usually detected at 37oC or AHG Kell antibodies are primarily IgG Kell antibodies are not a concern when investigating possible cases of HDFN Anti-k is infrequently encountered
Kell antibodies are not a concern when investigating possible cases of HDFN
Reagent antibody screening cells may not detect antibodies directed against low-incidence antigens. Which antibody is most likely to go undetected? a. Vel b. S c. Kpa d. K
Kpa
Antibodies that are enhanced by enzymes
Rh, Jk, Le, P, and I
What is the most likely Lewis phenotype of a nonsecretor? a. Le(a−b−) b. Le(a+b+) c. Le(a+b−) d. Le(a−b+)
Le(a+b−)
Select the alleles within the Lewis system. a. Le, le b. Lea, Leb c. Le, Se, H d. Le, Le
Le, le
Which of the following antigens is poorly expressed on cord blood cells? a. K b. M c. Leb d. D
Leb
Which blood group system's antigens are associated with glycophorin A and glycophorin B? a. Duffy b. Kidd c. Lewis d. MNS
MNS
The four haplotypes of the MNS blood group system are: MS, Ms, NS, Ns MN, Mn, Ns, NS Mm, Nn, Ss, Ms Ms, MS, NM, Nm
MS, Ms, NS, Ns
A decreased expression of Kell antigens on red blood cells is the result of: 2-aminoethylisothiouronium bromide (AET) The null phenotype McLeod phenotype ZZAP (dithiothreitol plus cysteine-activated papain)
McLeod phenotype
A group A pos individual is massively bleeding and rapidly depleting your A pos stock. You have 20 0 pos, 20 B pos and 10 AB pos. State your alternate choice and reason for selection.
My alternate choice would be to use O positive. The recipient can receive positive blood because they are already positive. O would best be used since it would contain no antigen for the patients anti-B antibodies to react to.
Which of the following are located on glycophorin A (GPA)? M antigen N-like antigen All of the above are correct N antigen
N-like antigen
Universal plasma recipient:
O+
Universal red blood cell donor:
O-
What ABO types may donate to any other ABO type? O- AB-, A-, B- A-, B-, AB-, O- AB-
O-
Describe the type of individual who should be allowed to draw patient samples or perform blood bank tests.
Only individuals who understand the importance of blood bank protocols and adhere to them should be allowed to collect patient samples or perform tests
What does a minor crossmatch consist of? Recipient plasma and donor RBCs Recipient plasma and recipient RBCs Recipient RBCs and donor plasma Donor plasma and donor RBCs
Recipient RBCs and donor plasma: In contrast to the "major crossmatch" (recipient serum vs. donor red blood cells), the "minor" crossmatch is designed to test opposite compatibility: The donor's serum/plasma with the recipient's red cells. For example, to perform a minor crossmatch between a group A blood donor and a group B recipient, blood bank personnel would mix the donor's plasma/serum (containing anti-B antibodies) with the recipient's red blood cells. The two, of course, would be incompatible. Obviously, my example is silly, because no one would deliberately try to give group A blood to a group B recipient, but it illustrates the principle.
Which antibodies have Reactivity at RT IS phase.
The antibodies most often identified by a cold panel are Lewis, Lua, I, M, N and P1.
State the principle of the crossmatch.
The crossmatch involves testing the patient's serum with donor cells to determine whether the patient has an antibody that may cause a hemolytic transfusion reaction or decreased cell survival of donor cells. The patient specimen must be less than 72 hours old for compatibility testing so that it represents the current immunologic status of the patient.
Which antibodies reactivities are altered by pH.
The reactivity of some weak examples of anti-M are greatly enhanced when the pH of the serum is lowered.
State the primary importance of the immediate spin crossmatch.
To detect any major ABO incompatibility
List three (3) instances in which it may be necessary to transfuse blood of another type to the patient.
When group and type specific blood is unavailable, as in transfusing group A blood to an AB recipient. A patient, such as an A or B, is massively bleeding and depleting the type specific stock, there is a large number of group O units available, transfuse with group O. For ABO and/or Rh hemolytic disease of the newborn
When may IS (immediate spin) crossmatching be performed? When blood is being emergency released When a patient is being massively transfused When a patient has not been transfused in the past 3 months When there is no history of antibodies and the current antibody screen is negative
When there is no history of antibodies and the current antibody screen is negative
Individuals who are the Kell null phenotype: Will lack all Kell system antigens with the exception of Kx Only need to inherit one copy of the K0 gene to be affected Will lack all Kell system antigens Will not produce anti-Ku or anti-K5
Will lack all Kell system antigens with the exception of Kx
Can crossmatching be performed on October 14th using a patient sample drawn on October 12th?
Yes: Compatibility testing may be performed on a patient sample within 3 days of the scheduled transfusion; however, if the patient is pregnant or was transfused within 3 months, the sample must be less than 3 days old.
Select a situation in which you can identify a patient for sample collection to use in compatibility testing from the list below. a. Bar-coded band with patient's name and hospital identification number b. Printed hospital band attached to patient's bed c. Response of patient to verbal name recognition but not wearing a hospital identification band d. Chart next to patient that contains unattached hospital identification band
a. Bar-coded band with patient's name and hospital identification number
Which of the following red cell phenotypes is associated with the McLeod phenotype? a. Rhnull phenotype b. K0 phenotype c. U-negative phenotype d. absence of Kx antigens
absence of Kx antigens
What statement is true relative to anti-K? a. agglutinates in IAT phases of the antibody screen b. is usually of the IgM antibody class c. does not agglutinate with K+k+ panel cells d. loses reactivity in enzyme phases
agglutinates in IAT phases of the antibody screen
How do patients become sensitized to HLA antigens? a. pregnancies b. blood transfusions c. previous transplants d. all of the above
all of the above
Which set of antibodies could you possibly find in a patient with no history of transfusion or pregnancy? a. anti-I, anti-S, and anti-P1 b. anti-M, anti-c, and anti-B c. anti-A, anti-I, and anti-D d. anti-B, anti-I, and anti-Lea
anti-B, anti-I, and anti-Lea
Antibodies that are destroyed by enzymes
anti-Fy, M, N, and S
Which of the following antibodies is commonly associated with delayed transfusion reactions? a. anti-Lu b. anti-S c. anti-Jk d. anti-M
anti-Jk
Which of the following antibodies is characteristically clinically insignificant? a. anti-Kpb b. anti-S c. anti-Leb d. anti-Fya
anti-Leb
Enzyme-treated reagent red cells used in antibody identification can enhance antibody reactions. Which of the following antibodies is not enhanced with the use of enzyme-treated red cells? a. anti-M b. anti-Lea c. anti-Jkb d. anti-I
anti-M
An antibody was detected at 37C and did not react at AHG phase. Which of the following should be suspected?
anti-N
Which of these antibodies are typically IgM? You may select more than one answer. a. anti-K b. anti-S c. anti-U d. anti-N e. anti-Le f. anti-Jk g. anti-P1
anti-N, anti-Le, anti-P1
The red cells of a donor have a U-negative phenotype. What red cell antibody would not react with these red cells? a. anti-M b. anti-S c. anti-P1 d. anti-K
anti-S
Which of the following antibodies is neutralized by pooled human urine? a. anti-Csa b. anti-Sda c. anti-Ch d. anti-Vel
anti-Sda
What alloantibody is associated with individuals possessing the p phenotype? a. anti-P2 b. anti-p c. anti-P d. anti-Tja
anti-Tja
Which of the following antibodies requires the antiglobulin test for in vitro detection? a. anti-M b. anti-P1 c. anti-U d. anti-I
anti-U
The removal of an antibody from serum or plasma using the individuals own red cells is:
autoadsorption
Situation: A group O, Rh(D)-negative patient has a positive DAT. Select the statement that would accurately describe the outcome of subsequent results in compatibility testing. a. All major crossmatches would be incompatible. b. The weak D test and control would be positive. c. Forward and reverse ABO grouping would be discrepant. d. Antibody screen would be positive at AHG phase.
b. The weak D test and control would be positive.
You performed an immediate-spin crossmatch and observed hemolysis in the test tube. What is your interpretation of the crossmatch? a. Compatible b. Incompatible c. Indeterminate; repeat
b. incompatible
Consider the following compatibility testing information: Patient has a negative antibody screen and no history of previous antibody formation. Which crossmatch procedure would apply? a. AHG crossmatch b. Immediate-spin crossmatch only c. Computer crossmatch and immediate-spin crossmatch d. Immediate-spin and AHG crossmatch
c. Computer crossmatch and immediate-spin crossmatch
A unit labeled as group O, Rh(D)-negative was checked by the transfusion service, with the following results. Donor Red Cells + anti-A,B = 0 Donor Red Cells + anti-D = 3+ What is the next step for this labeling discrepancy? a. Discard the unit b. Perform a weak D test c. Notify the collection facility d. Transfuse as group O, Rh(D)-negative
c. Notify the collection facility
Define "kernicterus".
caused when the basal ganglia and other areas of the brain and spinal cord are infiltrated with bilirubin resulting in mental retardation or death if not treated
Select the disease commonly associated with the McLeod phenotype. a. infectious mononucleosis b. chronic granulomatous disease c. Hodgkin disease d. PCH
chronic granulomatous disease
What term defines a list of all surgical procedures performed in the facility with the standard blood order for the stated procedure? a. Patient blood management b. Pre-admission testing c. Massive transfusion protocol d. Maximum Surgical Blood Order Schedule
d. Maximum Surgical Blood Order Schedule
Select the situation that would cause an incompatible AHG crossmatch in one of six donor units. a. Recipient's red cells contain a low-frequency antigen b. Recipient's red cells are polyagglutinable c. Recipient has a warm autoantibody d. Recipient has an alloantibody to a low-frequency antigen
d. Recipient has an alloantibody to a low-frequency antigen
The antibody screen:
detects most clinically significant antibodies
The procedure that removes intact antibodies from the red cell membrane is:
elution
The crossmatch procedure has many limitations. List six (6) things that a compatible crossmatch can/may not do.
guarantee normal survival of transfused RBCs prevent immunization of the recipient detect all unexpected red blood cell antibodies in the recipient serum prevent delayed hemolysis due to an anamnestic antibody response to antigens against which the patient has previous but undetectable immunization detect all ABO grouping errors either in donor or recipient detect most D grouping errors in the donor or recipient.
Methods to enhance antigen-antibody rxn
increasing serum to cell ratio, increase the incubation time, change incubation temp, for weak reacting antibodies use additional enhancement media (LISS, PEG), use fresh serum specimen
Which of the following is a high frequency antigen? K Kpa anti-Jsa k
k
Which blood group system possesses the Jsb and Kpa antigens? a. Duffy b. Lutheran c. Kell d. Kidd
kell
Examples of antibody enhancement reagents include:
low ionic strength saline, 22% boline albumin, polyethylene glycol
What is the first and second choices for when an alternate blood group must be transfused for blood group O
none (must be O)
What statement is true regarding a phenotype of Lu(a−b−)? a. rare in whites but not blacks b. rare in blacks but not whites c. rare in all populations d. common in all populations
rare in all populations
What term describes a poor platelet response to transfused platelets due to the presence of HLA or platelet antibodies? a. haplotype b. refractory c. vasoactive d. thrombocytopenia
refractory
What procedure helps distinguish between an anti-Fya and anti-Jka in an antibody mixture? a. lowering the pH of the patient's serum b. using a thiol reagent c. testing at colder temperatures d. testing ficin-treated panel cells
testing ficin treated panel cells
What is the primary purpose of the crossmatch procedure?
to prevent the transfusion of incompatible cells
T/F? Patient blood management identifies patients at risk of transfusion and provides a management plan to reduce or eliminate the risk of anemia and the need for allogeneic transfusion.
true
The S and s antigens: Are not antithetical Are located on glycophorin A Vary by a single amino acid at position 29 Are low incidence
vary by a single amino acid at position 29
List two (2) things a compatible crossmatch will indicate.
verify, in most instances, that donor's red cells are ABO compatible with the patient and detect most antibodies in the recipient's serum directed against antigens on the donor red cells.