Exam Flashcards
What is the Fisher-Race terminology for R0?
Dce
Which of the following tests can be used to determine the dosage of Rh-immune globulin needed for a postpartum woman to prevent Rh sensitization?
Kleihauer-Betke assay
All of the women described below are Rh-negative, weak D-negative, and delivered Rh-positive infants. Identify the woman who wound NOT benefit from the administration of Rh-immune globulin (RhIg)?
Group B; positive antibody screen; anti-D indentified; did not receive antepartum RhIg
Which of the following matings has the potential to result in hemolytic diseases of the newborn (HDN) due to antigens in any of the systems identified?
Mother’s phenotype: V, dce; Father’s phenotype: O, DCce
What should be done when a woman who is 24 weeks pregnant has a positive antibody screen?
Perform an antibody identification panel; titer if necessary
Should an A-negative woman who has just had a miscarriage receive RhIg?
Yes, but only if she does not already have anti-D from a previous pregnancy
Which of the following patients would be a candidate for RhIg?
O-negative mother; A-positive baby; second pregnancy; no anti-D in mother
All of the following tests are routinely performed on a cord blood sample except:
Antibody screen (DAT, Rh typing, and Forward typing ABO are performed)
Blood for intrauterine transfusion should be all of the following except:
More than 7 days old (it should be: irradiated, leukoreduced, and screened for CMV)
Kernicterus in newborns is caused by effects of:
unconjugated bilirubin
When determining the ABO group, both red blood cell and serum/plasma testing are performed in order to:
confirm RBC and serum results
If you detect an ABO discrepancy, what is the first step in its resolution?
Perform a clinical check and repeat testing
Mixed field agglutination may be observed in the following situations:
Hematopoietic progenitor cell (HPC) transplantation; A3 cells reacting with conventional anti-A; chimerism
Because the antibody screen was positive, a panel was performed. Anti-P1 was identified. The cause of the ABO discrepancy and positive antibody screen are most likely the same
TRUE
Of the following, which additional test should be performed to resolve the ABO discrepancy?
Repeat reverse grouping with P1 negative units
The injection of antibody into a person to provide temporary immunity is classified as:
Artificially acquired passive immunity
Antibodies are also known as:
immunoglobulins
Which antibody is able to cross the placenta?
IgG
The mating of a rr individual with a R1R2 individual can produce offspring with which of the following phenotypes?
D+ C= c+ E+ e+
Le(a-b+) individuals will usually have a naturally-occurring anti-Lea
FALSE
Which of the following is the correct conversion of r1 to fisher Race nomenclature?
dCe
The K antigen is highly immunogenic
TRUE
What is an allele?
observable expression
Which antibody class is present as a pentamer?
IgM
what is the necessary precursor substance for ABO antigens?
H
Which of the following is true for newborns?
Tests for antibodies are not reliable until 6 months of age
When testing with antiglobulin reagent, all negative tests
must have IgG coated cells added to the test system
At what temperature Celcius do IgM antiboides react best
20
Generally, most non-ABO clinically significant antibodies are what class?
IgG
Which blood group system is NOT manufactured by the red blood cells?
Rh
The K antigen is not well-developed at birth.
FALSE
Mixed field reactions could be caused by
recent transfusion
The Fy(a-b-) phenotype:
is observed in the majority of the African American population
Which of the following have been shown to cause hemolytic transfusion reactions?
Anti-Fy(a); Anti-K; Anti-c
IgM antibodies can readily agglutinate red blood cells
TRUE
Poly Anti Human Globulin reagent contains antibodies to
IgG, C3d
A test used to detect antibody coating in vivo is
DAT
You are performing an antibody screening test using the tube method. After reading the antiglobulin phase, you add IgG-sensitized cells and get a negative reaction. All of the following are possible explanations EXCEPT:
Failure to add potentiator cells
Which of the following constitutes and auto control
patient’s plasma mixed with patient’s red cells
To identify an anti-Fya, testing should be performed at which phase?
IAT
Dosage refers to an antibody reacting:
weaker with a heterozygous cell
What does anti-Human Globulin (AHG) reagent do?
Cross-links RBCs that have become sensitized with antibody or complement
A gene that produces no detectable product is referred to as:
An amorph
If you are crossmatching for a patient who has an antibody to an antigen present in 50% of the population, how many units do you need to test to find 5 units?
10
When loci are on different chromosomes they are said to be in:
trans position
A patient has the phenotype D= C+ c= E= e+. If transfused with blood from many O negative donors, the patient is most likely to develop which antibody?
Anti-c
Which genotype is heterozygous for E?
R2r
Anti-k (KEL2) is not a common cause of transfusion reactions because:
The corresponding antigen is common
What is the function of an elution
To remove antibody from the red blood cell surface to identify the antibody specificity
A cord blood sample was sent to the blood bank for an ABO type and DAT. Cells were washed 6x with saline before testing. The forward grouping typed as blood group O and there was no agglutination of the baby’s cells with anti-D. The DAT was 3+ with polyspecific AHG. What is the Rh type of the baby?
Rh type cannot be determined
The term used to describe when a pair of identical alleles are inherited from the parents:
homozygous
A doctor has ordered four units of red blood cells for a patient with anti-E in his serum. The frequency of the E antigen in the general donor population is 29%. How many units would have to be screened to yield four E-negative units?
6
A patient has the following genotype: AO, sese, Lele, Hh. Which of the following soluble antigens would be present in the saliva?
Lea
GVHD is prevented by:
irradiating cellular products prior to transfusion
Which of the following is NOT a cause of hemolysis after red cell transfusion
patient has IgA deficiency
Acute hemolytic transfusion reactions are most often caused by:
ABO incompatibility
Which of the following are symptoms of a hemolytic transfusion reaction?
fever, chills, hypotension, chest pain, hemoglobinuria
which of the following is NOT characteristic of delayed hemolytic transfusion reactions?
association with leukopenic patients
Which of the following are NOT true concerning nonhemolytic transfusion reactions
associated with temperature increase of >1 degree F
Febrile reactions may be prevented by:
transfusion of leukocyte depleted products
Most allergic reactions can be prevented by the use of :
antihistamines
TRALI may be fatal if caused by:
antibodies in donor plasma interact with recipient leukocyte antigens
anaphylactic reactions may occur when;
An IgA deficient patient has anti-IgA that reacts with transfused plasma
What is the 1st action that should take place when a transfusion reaction is suspected
stop the transfusion
hives and itching are symptoms of which of the following transfusion reactions
allergic
which of the following reactions is characterized by chills, fever, hemoglobinuria, back pain, DIC, and renal failure
hemolytic
In a delayed transfusion reaction, the causative antibody is generally too weak to be detected in routine compatibility testing and antibody screening tests but becomes detectable at what point after transfusion?
1-5 days
What is the most common cause of hemolytic transfusion reactions (HTR)
clerical errors
What would be the result of group A blood given to a group O patient
immediate hemolytic transfusion reaction
what is the terminal sugar of the precursor substance for ABH antigens
D-galactose
what is the necessary precursor for ABO antigens
H substance
What is meant by “forward typing”
testing donor/patient cells with Anti-A and Anti-B reagent
The majority of ABO typings are performed at what temperature
20-24 degrees C
All persons who are group O make which antibodies
Anti-A, Anti-B, and Anti-A,B
What do ABH genes code for
enzymes
ABH antibodies may be difficult to observe in which of the following populations
elderly and very young infants
A patient’s red cells react with commercial Anti-A and the plasma reacts with commercial group B red cells. What is the patient’s blood type
A
What color is the anti-B reagent
yellow
which lectin agglutinates A1 red blood cells
Dolichos biflorus
A technologist requires 2 more A2 positive cells to finish testing an ABO discrepancy. How many A units would they need to screen to find 2 A2 positive units
10
Which reaction is typical of the A3 subgroup
mixed field agglutination with Anti-A reagent
Which of the following donor cells will give the STRONGEST reaction with anti-H
A subgroups
which of the following would be useful in determining the presence or absence of H antigen on a red blood cell
Ulex europaeus
All persons with the true Bombay phenotype have antibodies against which antigens?
H
