Bloodbank Exam 3 Study Questions

What is the purpose of the antibody screen?

a- detects most clinically significant antibodies

Select a characteristic of HTLA antibodies

are usually clinically insignificant

Which statement is a characteristic associated with anti-I?

it does not react with cord blood cells

A multiple antibody problem was resolved using enzymes. Panel cell reactions were eliminated for one antibody specificity after testing with enzyme-treated red cells. Which of the following antibodies was probably present?

anti- Fy a

What is the definition of an antibody demonastrating dosage?

double dose (homozygous) red cells were stronger

The neutralization technique was performed on a sample containing an anti-Le b. The control and the Lewis-neutralized sera were both negative when retested with panel cells. How would you interpret the results of this test?

the sample was probably diluted

Jane Smith has a warm autoantibody reacting with all red cells. She received a transfusion 1 month ago. What procedure would you use to look for underlying alloantibodies?

sllogenic adsorption

What would the DAT results demonstrate if the test was performed on a clottled sample stores at 4 degrees C?

in vitro complement attachment

Which of the following antibodies may not be detected in the antibody screen?

anti-V

What is the name of the procedure that removes intact antibodies from the red cell membranes?

elution

What is the name of the procedure that removes antibody from serum or plasma using the individual’s own red cells?

autoadsorption

An antibody reacted in the screen at 37 degrees C and did not react at the AHG phase. Which antibody would you suspect?

anti-N

What is the period when no antigen typing should be performed on a patient’s red cells after transfusion?

up to 3 months

DTT is a useful reagent in evaluating a sample with a suspected antibody in which of the following blood group systems?

Kell

Why are additional procedures requires when working up a warm autoantibody?

identify potential underlying alloantibodies

Diagnosis, drug therapy, transfusion history, and previous pregnancy/ transplantation are important items when investigating a patient’s medical history

true

The drug methyldopa is linked to the drug-adsorption mechanism of drug-induced AIHA

false

Cold autoantibodies are almost always IgM, bind complement, and are removed by the spleed, leading to intravascular hemolysis.

false

Daratumumab interference in antibody screening can be eliminated by treating screening cells with DTT.

true

A cold alloantibody can cause ABO discrepancy in reverse grouping.

true

What test detects serologic incompatibility between donor RBCs and recipient serum?

crossmatch

A record review of Jane Hope revealed a history of anti-Jk (a). Her phenotype is group AB, D-positive. Current pretransfusion testing demonstrates a negative antibody screen. Select the further testing strategy before the transfusion of two RBC units.

provide Jk(a-) RBC units crossmatch compatible in antiglobulin crossmatch

During the issue of an autologous whole blood unit, you observe a dark red plasma layer. Select the best course of action.

do not issue the unit and place in quarantine

The transfusion service receives one group B, D-positive RBC unit. What repeat testing is required on this donor unit?

ABO typing only

What RBC units are issued to a woman of childbearing age in emergency release?

Group O, D-negative

Select the antibodies detected in the immediate-spin crossmatch.

ABO antibodies

Current pretransfusion testing on John Smith reveals a negative antibody screen. There is no history of alloantibody production. He is group A, D-positive. The transfusion order is three units of red blood cells. Which procedure can be used to identify compatible units?

immediate-spin crossmatch and computer crossmatch

The recipient’s phenotypes are group AB, D-positive and has a positive antibody screen. Antibody identification confirmed the presence of an alloanti-M. The transfusion order requires 1 unit of RBCs. The crossmatch on the selected donor unit is compatible. Select a possible explanation for these results.

donor is a heterozygote for the M antigen

What information does the AABB standards require on a labeled blood sample for the blood bank?

two independent identifiers

Which of the following products is crossmatched with the recipient if the unit contains greater than 2mL of RBCs

granulocyte concentrates

A patient who phenotypes as group AB, D-negative requires 1 unit of plasma. Which of the following units of plasma would be best for transfusion?

Group AB, D-positive

A donor’s RBC phenotype gave the following results: Anti-A 4+, Anti-B 0, Anti-D 3+.

The donor unit label states group A, D-negative. What is the next step?

notify the collection facility

An antiglobulin crossmatch result is 2+ agglutination reaction after the addition of the antihuman globulin reagent. What is the most likely explanation for this result?

recipient possesses an IgG alloantibody

A recipient’s antibody screen is negative; however, the recipient is incompatible with selected donor unit. Select a possible explanation for these results

recipient possesses an antibody to a low-frequency antigen

The computer crossmatch does not require validation for implementation.

false

A crossmatch detects most errors in the identification of antigens on patient’s red cells

flase

A crosssmatch demonstrating a 2+ agglutination is compatible

false

An immediate-spin crossmatch of a D-positive recipient with a D-negative donor unit is usually incompatible.

false

The computer crossmatch does not require ABO and D phenotype on the current recipient’s sample.

false

A crossmatch prevents the immunization of the recipient to blood group antigens

false

A type and screen protocol provides a mechanism to increase the number of uncross matched donor units in inventory.

true

The only component requiring a crossmatch is a unit of RBC

false

Group O plasma is the universal donor of plasma products

false

A good practice for recipient’s sample is to label with full name, a second unique identifier, date collected, and some means of identifying the phlebotomist

true

If a patient has been pregnant within the last 3 months before transfusion, the pretransfusion sample must be no more than 3 days old at the time of intended transfusion.

true

What item listed is not a goal for performing a whole blood exchange transfusion?

provide platelets to prevent disseminates intravascular coagulation

What is the greatest danger to a fetus affected by HDFN before delivery?

anemia

Select the volume of whole blood covered in an FMH with a 300-microgram dose of RHIG

30mL

What is the time frame for RhIG administration after delivery?

72 hrs

What is the name of an often-fatal condition characterized by general edema that results from anemia?

hydrops fetalis

What is the mechanism for HDFN occurrence?

maternal antibodies react with fetal antigens

What is the greatest danger to the newborn affected by HDFN postpartum?

kernicterus

Which of the following women should receive postpartum RhIG?

mother A, D-neg, neg antibody screen. Newborn O, d-pos

Which of the following antibodies carries no risk of HDFN?

anti- Le a

Which of the following is not a characteristic of ABO HDFN?

strongly positive DAT

Which of the following requirements is important when selecting blood for exchange transfusion to avoid elevated levels of potassium?

blood less than 7 days old

A mother is group A, D negative with anti D in her serum. Select the appropriate units for an intrauterine transfusion.

group O, D-neg

Select the statement that is true regarding the rosette test.

used to screen for FMH

Which of the following tests is not necessary when testing a cord blood sample?

antibody screen

What is the principle of the Liley method for predicting the severity of HDFN?

change of optical density of amniotic fluid measured at 450 nm

A D-negative woman with anti-D has a titer performed on her week 24 prenatal sample. After 4 weeks, another sample was tested in parallel with a current sample. Interpret the titer’s results.

consider Doppler ultrasonogrpahy

A group A, D-negative mother demonstrating anti-D antibodies delivered a group O, D-negative baby with a positive DAT (2+), elevated bilirubin (18 mg/dL), and low hemoglobin (8g/dL). Which is the most probable explanation for these test results?

HDFN with a false-neg D typing due to blocking antibodies

How would you interpret the appearance of spherocytes in a baby’s blood smear after delivery?

ABO HDFN

What is the purpose for the irradiation of blood selected for an exchange transfusion?

prevent graft vs host disease

What FMH bleed is detectable by the rosette test?

10 mL

A Kleihauer-Betke stain performed on a postpartum blood sample demonstrated 10 fetal cells in a field of 2000. What is the estimated blood volume of the fetomaternal hemorrhage expressed as whole blood?

25 mL

A rosette test performed on a D-negative mother who delivered a D-positive baby demonstrated two rosettes per three fields observed. What is the correct course of action?

submit the sample for a Kleihauer-Betke test

What is the principle of the Kleihauer-Betke test?

fetal hemoglobin resists acid elution

Results of Kleihauer-Betke test determine there was a fetomaternal hemorrhage of 35 mL of whole blood during delivery. What is the correct dosage of RhIG?

one vial

A weakly reactive anti-D was present in a postpartum sample from a D-negative woman who gave birth to a D-positive baby. What is the most probably cause?

antenatal RhIG given