blood bank rotation exam B, EXAM C
bloodbank, exam D blood bank
Questions with 100% Correct Answers
definition of a titer Correct Answer: the minimum volume of a solution needed
to reach the endpoint in a titration
The titer of a immunologic reaction is: Correct Answer: The highest —-->
Serial dilutions are made of the antibody containing plasma and tested against
selected red blood cells to determine the highest dilution causing a positive
reaction.
The result or titer is expressed as the reciprocal of the highest plasma dilution
reacting 1+.
Enzymes Correct Answer: 1. Enzymes are proteins that increase the rate of a
chemical reaction.
2. In transfusion medicine, enzymes are used to alter red blood cell antigens.
3. The most commonly used are ficin and papain.
4. Less commonly used enzymes are bromelin, pronase, trypsin, and
chymotrypsin.
5. Some red blood cells are destroyed by enzymes, while the reactivity of other
antigens is enhanced.
Enzyme treatment can be performed in two ways: Correct Answer: The one-step
technique: Enzyme is added as an enhancement to the tube containing test
plasma and red blood cells and carried through the IAT phase of testing.
,The two-step technique: Requires treatment of the red blood cells with enzymes
and washing prior to the addition of patient plasma. This method is often
preferred because the enzymes in the one-step technique are added directly
to the patient's plasma and any antibodies present may be damaged.
Neutralization Correct Answer: The inactivation of an antibody by combining it
with a soluble form of the corresponding antigen.
P1 antigen Correct Answer: neutralization: Hydatid cyst fluid, Pigeon eggs
Rare hemolytic IgG component
Associated with PCH, parasitic infection
I antigen Correct Answer: Neutralization: Breast milk
Tested with cord blood
Stimulated by M. pneumoniae (I-like Ag)
Fy a antigen % Correct Answer: 66%
Fy b antigen % Correct Answer: 83%
K antigen % Correct Answer: 9%
k antigen % Correct Answer: 99.8%
,S antigen % Correct Answer: 55%
s antigen % Correct Answer: 89%
Jka antigen % Correct Answer: 77%
Jkb antigen % Correct Answer: 72%
Kpa is a low-frequency antigen Correct Answer: only 2%
Kpb is a high-frequency antigen Correct Answer: (99.9%)
Js a antigen % Correct Answer: 0.1% in white
20% in black
Jsb antigen % Correct Answer: both white and black 99%
Cold Hemagglutinin Disease Correct Answer: → anti-I, anti-i, anti-Pr
Acute: secondary to lymphoproliferative diseases or M. pneumoniae
Chronic: elderly patients, may result in Raynaud's and hemoglobinuria
Lab findings: reticulocytosis, positive DAT due to complement (IgM), negative
eluate
Agglutinated RBCs, polychromasia, anisocytosis, poikilocytosis
Rabbit Erythrocyte Stroma Test (REST) Correct Answer: Used for patients that
were recently transfused
, Anti-I prefers the I antigens on rabbit cells → Antibody is absorbed out
CAUTION: may absorb clinically significant antibodies (D, E, Vel) and IgM
Can be used to adsorb certain antibodies.
Removes cold autoantibodies, anti-B, and antibodies in the P blood group
system (anti-P1).
Cold autoadsorption Correct Answer: Cannot be performed on recently
transfused patients
Procedure: keep EDTA sample warm, separate serum, wash RBCs with warm
saline, add aliquot of serum to RBCs, incubate for 1 hour at 4°C, harvest serum
and test screen cells
All negative → no alloantibody
Positive and negative → alloantibody present, run panel
All positive → unsuccessful, repeat with absorbed sample
Paroxysmal Cold Hemoglobinuria Correct Answer: → anti-P, Donath-Landsteiner
Antibody
historically associated with syphilis infections
Usually an acute transient condition secondary to viral infection in children
Biphasic hemolysin causes hemolysis after exposure to cold
bloodbank, exam D blood bank
Questions with 100% Correct Answers
definition of a titer Correct Answer: the minimum volume of a solution needed
to reach the endpoint in a titration
The titer of a immunologic reaction is: Correct Answer: The highest —-->
Serial dilutions are made of the antibody containing plasma and tested against
selected red blood cells to determine the highest dilution causing a positive
reaction.
The result or titer is expressed as the reciprocal of the highest plasma dilution
reacting 1+.
Enzymes Correct Answer: 1. Enzymes are proteins that increase the rate of a
chemical reaction.
2. In transfusion medicine, enzymes are used to alter red blood cell antigens.
3. The most commonly used are ficin and papain.
4. Less commonly used enzymes are bromelin, pronase, trypsin, and
chymotrypsin.
5. Some red blood cells are destroyed by enzymes, while the reactivity of other
antigens is enhanced.
Enzyme treatment can be performed in two ways: Correct Answer: The one-step
technique: Enzyme is added as an enhancement to the tube containing test
plasma and red blood cells and carried through the IAT phase of testing.
,The two-step technique: Requires treatment of the red blood cells with enzymes
and washing prior to the addition of patient plasma. This method is often
preferred because the enzymes in the one-step technique are added directly
to the patient's plasma and any antibodies present may be damaged.
Neutralization Correct Answer: The inactivation of an antibody by combining it
with a soluble form of the corresponding antigen.
P1 antigen Correct Answer: neutralization: Hydatid cyst fluid, Pigeon eggs
Rare hemolytic IgG component
Associated with PCH, parasitic infection
I antigen Correct Answer: Neutralization: Breast milk
Tested with cord blood
Stimulated by M. pneumoniae (I-like Ag)
Fy a antigen % Correct Answer: 66%
Fy b antigen % Correct Answer: 83%
K antigen % Correct Answer: 9%
k antigen % Correct Answer: 99.8%
,S antigen % Correct Answer: 55%
s antigen % Correct Answer: 89%
Jka antigen % Correct Answer: 77%
Jkb antigen % Correct Answer: 72%
Kpa is a low-frequency antigen Correct Answer: only 2%
Kpb is a high-frequency antigen Correct Answer: (99.9%)
Js a antigen % Correct Answer: 0.1% in white
20% in black
Jsb antigen % Correct Answer: both white and black 99%
Cold Hemagglutinin Disease Correct Answer: → anti-I, anti-i, anti-Pr
Acute: secondary to lymphoproliferative diseases or M. pneumoniae
Chronic: elderly patients, may result in Raynaud's and hemoglobinuria
Lab findings: reticulocytosis, positive DAT due to complement (IgM), negative
eluate
Agglutinated RBCs, polychromasia, anisocytosis, poikilocytosis
Rabbit Erythrocyte Stroma Test (REST) Correct Answer: Used for patients that
were recently transfused
, Anti-I prefers the I antigens on rabbit cells → Antibody is absorbed out
CAUTION: may absorb clinically significant antibodies (D, E, Vel) and IgM
Can be used to adsorb certain antibodies.
Removes cold autoantibodies, anti-B, and antibodies in the P blood group
system (anti-P1).
Cold autoadsorption Correct Answer: Cannot be performed on recently
transfused patients
Procedure: keep EDTA sample warm, separate serum, wash RBCs with warm
saline, add aliquot of serum to RBCs, incubate for 1 hour at 4°C, harvest serum
and test screen cells
All negative → no alloantibody
Positive and negative → alloantibody present, run panel
All positive → unsuccessful, repeat with absorbed sample
Paroxysmal Cold Hemoglobinuria Correct Answer: → anti-P, Donath-Landsteiner
Antibody
historically associated with syphilis infections
Usually an acute transient condition secondary to viral infection in children
Biphasic hemolysin causes hemolysis after exposure to cold
