Blood Bank Ch 2 Review
Select the sources of antigen for immunohematology testing.
Commercial and patient red cells
Hemolysis was observed at room temperature when testing a patient's serum with reagent red cells used for screening. When this test was repeated using the patient's plasma, no hemolysis was observed. What was the most likely explanation for the different reactions?
Complement activation was inhibited by calcium in the plasma sample.
In transfusion medicine, what is the name of the process whereby antibodies attached to red cell antigens signal clearance in the liver and spleen?
Extravascular hemolysis
An antibody molecule can possess one kappa and one lambda light chain.
False
What is the potential effect in a tube agglutination result if a red cell suspension with a concentration less than 5% is used?
False negatives
What is the potential effect in a tube agglutination test if a red cell suspension with a concentration greater than 5% is used?
False negatives
A technologist added 4 drops of a 5% red cell suspension instead of the required 1 drop to a hemagglutination test. What is the potential consequence to the test results?
False-negative
What part of the immunoglobulin molecule distinguishes the isotype?
Heavy chain
Found in mucosal linings
IgA
can initiate allergic reactions
IgE
What antibodies are best detected at 37° C and can cause immune-mediated destruction of transfused red cells possessing the corresponding antigen?
IgG
Which immunoglobulin class is impacted by the zeta potential in a hemagglutination test?
IgG
able to cross the placenta
IgG
detected with the antiglobulin test
IgG
highest plasma/serum concentration
IgG
Contains 10 antigen-binding sites
IgM
Produced early in an immune
IgM
activates the complement cascade most efficiently
IgM
associated with intravascular cell destruction
IgM
detected in the immediate-spin phase of the agglutination test
IgM
reacts best at room temperature
IgM
shape is a pentameter
IgM
Which of the following requires adjustment in order to enhance the reaction of an antibody in vitro?
Increase the incubation time in the incubator
After addition of anti-A reagent to a patient's red cell suspension, agglutination was observed. The result with anti-B reagent was negative. What is the interpretation of this patient's ABO typing?
Patient is group A
What process is described by the engulfment of antibody-coated red cells?
Phagocytosis
What cells can produce antibodies?
Plasma cells
What biological molecules are considered the most immunogenic?
Proteins
What type of immune response occurs within 1 to 3 days of exposure and contains a significant production of memory B cells?
Secondary
How does complement activation demonstrate within the body?
cell lysis enhanced cell clearance neutrophil activation generation of vasoactive amines (all of the above)
To determine the presence of a red cell antibody in a patient's sample, what is the source of antigen?
commercial reagent red cells
Select the term that describes the unique part of the antigen that is recognized by a corresponding antibody.
epitope
What is the chemical composition of an antibody?
glycoprotein
Which of the following situations can enhance hemagglutination reactions?
increasing the incubation time
What classification of molecules does not make a good immunogenic substance?
lipid
Where is the antigen located in a hemaglutination test?
on the red cell membrane
What term describes molecules that bind to an antigen to increase phagocytosis?
opsonins
After performing a tube test, that supernatant of the test was pinkish and the red cell button was small. How do you interpret the result of this test?
positive
Extravascular destruction of blood cells occurs in the:
spleen
What term describes the number of antigen-binding sites per molecule of antibody?
valency
After adding antigen and antibody to a test tube, small agglutinates with many unagglutinated cells were observed. How should this reaction be graded?
1+
How would you grade an agglutination reaction of you observe many small agglutinatinates in a background of free cells in tube testing?
1+
After adding antigen and antibody to a test tube, one large agglutinate was observed. How should this reaction be graded?
4+
What is the classification of red cell antibodies produced in response to transfusion and pregnancies?
Autoantibodies
Select the cells that will undergo transformation to become plasma cells.
B lymphocytes
Which of the following components in the complement cascade mediates the lysis of the target cells?
C5 to C9
