BB - ASCP Study - Misc. questions

Which of the following patients are at risk for transfusion-associated graft versus host disease (TA-GVHD) and require irradiated cellular blood products? (Choose all that apply) a. Neonates less than 4 months of age b. Recipients of donor units known to be from a blood relative. c. Patients with chronic anemias. d. Patient receiving chemotherapy who are immunocompromised. e. Patients with a history of allergic reactions.

a. b. d. Certain recipients have increased risk for developing TA-GVHD. They are: **Neonates less than 4 months of age **Fetuses **Recipients with a congenital or acquired immunodeficiency, such as bone marrow or stem cell recipients, and patients receiving chemotherapy **recipients of donor units from a blood relative

An issued unit of blood may be returned to blood bank inventory if it has not been outside a monitored refrigerator for longer than: a. 30 minutes b. 60 minutes c. 2 hours d. 3 hours e. 6 hours

a. 30 minutes If, for instance, transfusion is delayed, a unit of blood must be returned to a temperature-monitored refrigerator within 30 minutes to maintain the integrity of the blood cells.

Which one of the following procedures is used for the proper preparation of Platelet concentrate from random whole-blood donors? a. Light spin followed by a hard spin b. Light spin followed by two hard spins c. Two light spins d. Hard spin followed by a light spin e. Two hard spins

a. Light spin followed by a hard spin The first step in preparation of Platelets from random whole blood donors is a low-speed centrifugation (light spin). This allows the platelets to remain in the plasma portion of the collection container. The plasma (dubbed "platelet-rich plasma") is then centrifuged at a higher velocity (hard spin) that forces the platelets to the bottom of the satellite bag. The platelet-poor plasma is expressed into another container and the residual platelets that remain in the bag are resuspended in a small volume of plasma.

When monitoring maternal antibody strength using a doubling dilution, an increase in titer from 16 to 32 is considered a significant rise in titer. a. True b. False

b. False The statement is false. To be significant, a rise in titer needs to be a two tube increase or more. A rise in titer from 16 to 32 in a doubling dilution is only a one tube difference.

Which one of these Lewis blood group phenotypes usually produces anti-Lea a. Le(a+b+) b. Le(a+b-) c. Le(a--b+) d. Le(a--b-)

d. Le(a--b-) This antibody is found in the serum of Le(a-b-) secretors.

Which of the following Rh antigens is found in the highest frequency in the Caucasian population: a. C b. E c. c d. e

d. e The e antigen is present in 98% of the Caucasian population.

When testing a patient with a warm autoantibody, which of the following is the most important concern? a. Masking of other clinically significant antibodies b. Interference of plasma protein with detection methods c. Detection of donor antibodies d. Interference of rouleaux

a. Masking of other clinically significant antibodies Reactivity of a warm autoantibody may mask the presence of other clinically significant antibodies which adds to the possibility of a transfusion reaction. Further testing should be performed on the sample to determine if other antibodies are present.

Given the following commonly used nomenclature systems, which one of the Rh genotypes listed below is heterozygous for the C antigen? WienerFisher-Race (haplotype) RoDce R1 DCe R2DcE RzDCE rdce r'dCe r"dcE rydCE The correct answer is highlighted below a. R1r b. R1R1 c. R2r" d. r"r

a. R1r R1r is the only genotype listed that is heterozygous for the C antigen. Weiner = Fisher-Race R1r = DCe/dce R1R1 = DCe/DCe rr = dce/dce R1R2 = DCe/DcE R2r = DcE/dce R2R2 = DcE/DcE r'r = dCe/dce r'r' = dCe/dCe r"r = dcE/dce r"r" = dcE/dcE R0r =Dce/dce

A patient with a positive DAT due to IgG cannot be reliably antigen-phenotyped using antisera that reacts by the indirect antiglobulin test (IAT). a. True b. False

a. True A positive DAT precludes antigen phenotyping by IAT. IgG-sensitized red cells will react with the antiglobuin serum whether the cells are antigen positive or negative.

For which of the following antibodies is the DAT most likely to be negative when testing a newborn for possible HDFN? a. anti-A b. anti-c c. anti-D d. anti-K e. anti-Fya

a. anti-A The DAT is most likely to be negative in ABO HDFN. It's possible that the washing done as part of the DAT may break the bonds between anti-A (or anti-B) and the newborn's poorly developed A (or B) antigens.

The Kleihauer-Betke test used to quantitate FMH has poor reproducibility. a. True b. False

a. true Despite its widespread use, the Kleihauer-Betke test has poor reproducibility (as well as poor sensitivity).

What is the proper storage temperature for thawed Cryoprecipitate? a. 4 - 8 ºC. b. 20 - 24 ºC. c. 35 - 37 ºC. d. -20 ºC or colder

b. 20 - 24 ºC. Once thawed, cryoprecipitate must be kept at room temperature (20 - 24oC) and used within 6 hours after thawing.

Rh immune globulin is manufactured to be capable of neutralizing _____________ milliliters of Rh positive whole blood. a. 15 b. 30 c. 45 d. 450 e. 1000

b. 30 Rh immune globulin, also known as RhoGAM, can neutralize approximately 30 mL of Rh positive whole blood.

The accepted interval between blood donations is: The correct answer is highlighted below a. 12 weeks b. 8 weeks c. 6 weeks d. Depends on hematocrit level

b. 8 weeks The mandatory waiting period between blood donations is 56 days, or eight weeks.

A pregnant female who received RhIg at 28 weeks gestation has a positive antibody screen at delivery. If the antibody has been confirmed as anti-D alone and reacts 1+ in the indirect antiglobulin test with D+ red cells, performing a titration to investigate if the anti-D is immune is good practice. a. True b. False

b. False Because lower titers could be due to both passive and immune anti-D, in the absence of results that suggest immune anti-D, routine antibody titration is not a good use of time compared to assuming that anti-D is passive. Best practice guidelines do NOT recommend routine titration for women known to be injected with RhIg and exhibiting a 2+ or less reaction with D+ red cells consistent with passive anti-D from RhIg.

RhIg prevents anti-D production mainly by clearing antibody-sensitized D-positive rbc from maternal circulation. a. True b. False

b. False Initially researchers thought that RhIg prevented anti-D production by clearing the infant's D-positive rbc sensitized with maternal anti-D, but we now know this is not true. Currently, the mechanism by which RhIg prevents immunization to the D antigen is poorly defined. However, research shows that it likely involves down-regulation of antigen-specific B cells, ie., the B cells do not differentiate into antibody-excreting plasma cells as they normally would when presented with foreign antigens.

If a pregnant female who was injected with RhIg antenatally has anti-D at delivery, routine antibody titration to determine the titer of the anti-D is considered a good practice. a. True b. False

b. False Routine antibody titration is not considered a good practice. If the antibody strength is weak (e.g., 2+ or less, consistent with RhIg administration), titer cannot differentiate between passive and immune anti-D.

Which of the following is the MOST likely discrepancy seen when a person demonstrates an "acquired B-like" phenomenon a. Forward typing appears to be B, but reverse groups like O b. Forward typing appears to be AB, but reverse groups like A c. Forward typing appears to be O, but reverse groups like B d. Forward typing appears to be B, but reverse groups like AB e. Forward typing appears to be AB, but reverse groups like B

b. Forward typing appears to be AB, but reverse groups like A Acquired B is seen only in a subpopulation of group A1 individuals. The individuals that demonstrate acquired B possess anti-B, but this anti-B does not react with the acquired B antigen; consequently, the auto control is negative. These patients should be transfused with group A or O blood.

The most recent algorithm for HIV confirmatory testing in patients who are positive by ELISA is the: a. Latex agglutination for HIV-1/HIV-2 antigen b. HIV-1/HIV-2 antibody differentiation immunoassay c. Thin layer chromatography d. ELISA

b. HIV-1/HIV-2 antibody differentiation immunoassay According to the CDC, specimens with a reactive 4th generation immunoassay (or repeatedly reactive, if repeat testing is recommended by the manufacturer) should be tested with an FDA-approved 2nd generation antibody immunoassay that differentiates HIV-1 antibodies from HIV-2 antibodies (such as the Multispot© assay).

Which of the following antibodies usually show enhanced agglutination with the use of proteolytic enzymes? a. anti-M,N, and S b. anti-Jka, Jkb, C, and E c. anti-Fya and Fyb

b. anti-Jka, Jkb, C, and E Enzyme techniques are particularly useful in the identification of antibodies in the Rh system (e.g., anti-C and E) and in the Kidd system (e.g., anti-Jka and Jkb). Enzymes destroy some antigens, such as M, N, S, Fya, and Fyb. Therefore the corresponding antibodies would not be detected.

If an Rh group (DCe/dce) man marries an Rh group (dce/dce) woman, what is the probablitiy that their first child will be D-negative? a. 0% b. 25% c. 50% d. 75% e. 100%

c. 50% Since the inheritance pattern of the D-antigen is determined equally from the mother's and father's genotypes, the chances of producing a D-negative offspring is 50%. DCe (father) + dce (mother) = D positive dce (father) + dce (mother) = D negative

Which of the following represents the approximate percentage of the population that is Rh positive: a. 35 % b. 65 % c. 85 % d. 95 %

c. 85 %

The Kleihauer-Betke test is used to: a. Screen for sickle cell anemia b. Screen for fetal hemoglobin c. Differentiate between maternal and fetal red cells d. Screen for hemoglobin A1c

c. Differentiate between maternal and fetal red cells The Kleihauer-Betke test allows the differentiation of fetal and maternal red cells. The Kleihauer-Braun-Betke stain is based on the principle that fetal hemoglobin is resistant to acid elution, while adult hemoglobin is not. A smear of maternal blood is treated with acid, rinsed and counterstained. Fetal cells will stain and appear pink. Maternal cells appear as ghost cells. Generally, 2000 cells are counted and the number of fetal cells determined. The hemorrhage is estimated using the following formula: Fetal cells X maternal blood volume* / Total cells counted = Fetomaternal hemorrhage (mL of whole blood) * Maternal blood volume is estimated at 5000 mL

Patients with which of the following conditions would benefit most from washed red cells: a. Warm autoimmune hemolytic anemia b. Cold autoimmune hemolytic anemia c. Elevated serum potassium d. Multiple red cell alloantibodies

c. Elevated serum potassium Washing not only reduces the number of leukocytes and platelets that are often responsible for febrile reactions, but also eliminates anticoagulants, ammonia, lactic acid, and potassium.

The McLeod phenotype is associated with which of the following antigen systems? a. Rh b. P c. Kell d. Duffy e. MNSs

c. Kell The McLeod phenotype is associated with a decreased expression of Kell antigens on red cells.

Which one of the following blood group systems may show a cell typing change during pregnancy? a. Rh b. MNS c. Lewis d. Duffy e. D mosaic

c. Lewis The Lewis group antigen, Le^a may disappear during pregnancy, resulting in the formation of anti-Le^a antibodies. The majority of these antibodies are IgM and clinically insignificant.

An urticarial transfusion reaction is characterized by: a. Rapid rise in temperature b. Difficulty breathing c. Rash and hives d. Blood in the urine

c. Rash and hives Urticarial transfusion reactions occur in up to 1% of transfusions. They are manifested by hives, rash, and itching. The transfusion may be resumed after successful administration of antihistamines.

Which one of the following types of transfusion reactions caused the highest number of transfusion-related fatalities that were reported to the U.S. Food and Drug Administration (FDA) from 2005 - 2009? a. Anaphylactic reactions b. Febrile non-hemolytic reactions c. Transfusion-related acute lung injury (TRALI) d. Transfusion-associated graft versus host disease (TA-GVHD)

c. Transfusion-related acute lung injury (TRALI) In combined fiscal years 2005 through 2009, transfusion-related acute lung injury (TRALI) caused the higest number of reported fatalities (48%), followed by hemolytic transfusion reactions (26%) due to non-ABO (16%) and ABO (10%) incompatibilities. Complications of microbial infection, transfusion-associated circulatory overload (TACO), and anaphylactic reactions each accounted for a smaller number of reported fatalities.

The proper storage requirements for granulocyte concentrates is: a. 1 - 6 degrees Celsius, < 12 hours b. - 20 degrees Celsius, 48 hours c. 1 - 6 degrees Celsius, < 24 hours d. 20 - 24 degrees Celsius, < 24 hours

d. 20 - 24 degrees Celsius, < 24 hours Granulocytes may be stored at 20-24 degrees Celsius for up to 24 hours, but should be transfused as soon as possible.

Which unit contains the proper number of platelets from a random donor? a. 3.8 x 10^10 b. 4.0 x 10^10 c. 4.5 x 10^10 d. 5.8 x 10^10

d. 5.8 x 10^10 Platelet concentrates are required to have a minimum of 5.5 x 10^10 platelets/unit. Random donor platelet concentrates typically contains between 5.5 and 8.5 X 10^10 platelets suspended in about 50 mL of plasma. This is approximately 70% of the platelets which were present in the original unit of whole blood collected by the donor.

Which of the following refers to the most common procedure for donating whole blood for use by the general population: The correct answer is highlighted below a. Autologous donation b. Hemapheresis c. Directed donation d. Allogenic donation

d. Allogenic donation Allogenic donation is also known as homologous donation. In this procedure, donor blood products are collected for transfusion and given to a random (non-directed) patient in need.