Quizzes 1-6 Flashcards
The presence of blood group A is confirmed by detecting with anti-A the presence of which terminal sugar molecule?
N-acetyl-D-galactosamine
The mating of parents (ew) of which two ABO phenotypes can potentially produce offspring with ALL of the common four blood groups?
A + B
Which ABH substances would you expect to find in the saliva of a group B secretor?
H + B
A blood donor has the genotype hh, AB. What is his apparent red cell phenotype during routine forward and reverse grouping?
O
Which of the following genes codes for secretor status
Se
The labels came off your reagent bottles. What color is the anti-B reagent?
yellow
Most blood group systems are inherited as
codominant
What is the ABO group of the individual with the following serologic reactions:
Anti-A = 0, Anti-B= 0,
A1 cells = 4+, B cells = 4+
O
When a Ce haplotype is in trans to a D antigen encoding haplotype, which may occur
weak D phenotype with 1+ agglutination
A new blood bank specimen is required 24-48 hours following a blood transfusion because
secondary immune response against donor antigens
Which of the following is the most common subgroup of blood group A?
A1
Which is true regarding the anti-A1 antibody in an A2 individual?
Group O blood should be transfused if the anti-A1 reacts at 37°C
The plant lectin extracted from Dolichos biflorus will agglutinate
A1 cells but not A2 cells
Which of the following blood groups possesses the most H antigen?
Group O
All A subgroups always have which blood group circulating antibody
Anti-B
Identify the strength of the agglutination reaction that provides the best hint as to the type of ABO discrepancy
weakest
Which subgroup of blood group A shows mixed field agglutination with anti-A reagents?
A3
What is the ABO group of the individual with the following serologic reactions: Anti-A = +4, Anti-B= +4, A 1 cells = 0, B cells = 0, anti-D = 4+
AB positive
The observation of hemolyzed serum or plasma in a blood bank specimen is reason for
Rejecting the specimen
The coin-like stacking of RBCs that may cause an ABO discrepancy is called
Rouleaux formation, Group III
Rz phenotype is
DCE
r” phenotype is
cE
Weak D antigens
usually require an IAT phase for detection
Which is true of partial D?
partial D individuals may not be detected until develop the anti-D antibody
A serologic characteristic of the Del type of weak D antigen is
weak or undetectable agglutination reactions at IS (immediate spin)
Rh system antibodies
show dosage
Individuals of the Rh null phenotype produce which types of red cells?
stomatocytes
Which of the following constitutes the f antigen?
c & e on the same chromosome
What is the ABO group and Rh type of the individual with the following serologic reactions?
Anti-A = 0 Anti-B = 0 A cells = 4+ B cells = 4+ anti-D = 1+
O weak D
Identify the possible cause(s) for false positive reactions with Rh antibodies
Fibrin interference
Which of the following antigens are destroyed by ficin (and papain)?
Duffy
A common cause of delayed type hemolytic transfusion reactions are
anti-Jka and anti-Jkb
McLeod phenotype
presence of reticulocytes and hyperbilirubunemia
Which antigen is the second most antigenic after the D antigen
Kell
What is the ABO group and Rh type of an individual with the following serologic reactions: Anti-A = +4, Anti-B= 0, A 1 cells = 0, B cells = 4+, anti-D = 0
A negative
Kidd blood group system
antibodies usually bind complement
What is the next step if a patient with anti-M reacts at 37°C is crossmatch compatible at 37°C and negative at the anti-human globulin (AHG) phase
provide donor RBCs without phenotyping for the M antigen
Identify the high frequency (prevalence) antigen
Cellano
Identify the blood group system that has the highest percentage of antigen negative RBC units
Kell
Identify the characteristic associated with the Duffy antigen system
antibodies against Duffy antigens react at the AHG phase
1 What is the predominant major cause of an ABO mistransfusion?
clerical error in identifying patient by the phlebotomist when drawing the T&S
How should a patient be identified when drawing lab samples, processing lab samples, transfusing?
By double or preferably triple unique identifiers
What is the maximum age a T&S specimen for Blood Bank can be when a patient has been transfused or pregnant in the last 3 months?
48 - 72 hours
Which of the following tests are not required to be performed on all donor blood?
CMV
What is the minimum time after transfusion must a T&S and a segment of donor blood be retained?
7 days
What confirmatory testing must be performed on donor blood units by the blood bank transfusing the patient?
front type and Rh D if the unit is Rh negative
When may an Immediate Spin Crossmatch be performed?
Correct When the antibody screen is negative and there is no history of alloantibodies
The criteria for an incompatible cross-match or positive IAT is/are:
Agglutination and/or hemolysis
AHG is used to identify:
RBCs sensitized with IgG alloantibodies after 37C incubation
What does the IAT and cross-match have in common
Both test recipient serum or plasma that may have alloantibodies
What is/are the criteria for a positive cross-match therefore rejecting the donor RBC unit
Hemolysis and/or agglutination
Screening cells are all group O so as not to have interference by
anti-A or anti-B antibodies
Using a three cell screen, you observe that the reactions are 3+, 0, 1+ at Coombs respectively. This suggests the presence of:
A dosage effect
Identify the reagent that can act as agglutination potentiator, can cause non-specific agglutination, should not do a 37C reading and finish with AHG macroscopically
PEG
A key characteristic of a positive reaction (agglutination) with the gel card system is:
IgG in the gel traps sensitized RBC so they remain at the top of the gel
Antibody identification using a panel (of donor RBCs) requires as the first step:
Rule out all reagent RBCs that give negative reactions with homozygous antigen phenotype in all phases of testing
You ran out of check cells. What is your next step:
Sensitize Rh positive RBCs with reagent anti-D
Does the strength of agglutination with AHG signify clinical significance?
No
