10 SEROLOGICAL TESTING OF BLOOD PRODUCTS Flashcards
(1) What protocol is followed when screening whole blood donors for HIV-1 RNA?
A. Pools of 10 are tested; if the pool is nonreactive, donors are accepted
B. Pools of 20 are tested; if the pool is reactive, samples are tested individually
C. Pools of up to 16 donors are tested; if pool is reactive, individual samples are screened
D. All donors are screened individually; if samples are reactive, blood is discarded
C. Pools of up to 16 donors are tested; if pool is reactive, individual samples are screened
Pools of up to 16 donors are tested by nucleic acid amplification technology. If the pool is reactive, samples from each individual donor are tested. Pooled donors may also be screened for Zika virus using nucleic acid amplification.
(2) Currently, nucleic acid testing (NAT) testing is performed to detect which viruses?
A. HIV and Human T-cell lymphotropic virus (HTLV-1)
B. HTLV I/II
C. HIV, HCV, HBV, Zika, and West Nile virus (WNV)
D. HIV, HBV, and WNV
C. HIV, HCV, HBV, Zika, and West Nile virus (WNV)
According to the AABB standards, NAT testing is required for viruses HIV-1, HCV, HBV, Zika, and WNV.
(3) John comes in to donate a unit of whole blood at the collection center of the community blood supplier. The enzyme immunoassay assay (EIA) screen for anti-HIV-1,2 is nonreactive; however, the NAT HIV is reactive. After 8 weeks John is tested again and found to be NAT nonreactive and EIA anti HIV-1,2 nonreactive:
A. This renders him eligible for donation
B. Donation is deferred for 6 months
C. Status is dependent on further confirmatory testing
D. Donation is deferred for 12 months
A. This renders him eligible for donation
According to the FDA guidelines, donors who retest as NAT HIV nonreactive and negative for anti-HIV-1,2 are eligible to donate in their re-entry program.
(4) What marker is the first to appear in HBV infection?
A. Hepatitis B core antibody (anti-HBc) IgM
B. HbsAg
C. Hepatitis B surface antibody (anti-HBs)
D. Anti-HBc IgG
B. HbsAg
The first viral marker of hepatitis B to appear in the serum once exposed is the HBSAg, which appears in as few as 5 days (5–28 days) after exposure.
(5) What marker indicates immunity to hepatitis B infection?
A. Anti-HBc IgM
B. HBsAg
C. Anti-HBs
D. Anti-HBc IgG
C. Anti-HBs
Anti-HBs is indicative of immunity or vaccination to hepatitis B. Anti-HBc IgM occurs in the early stage of infection; anti-HBc IgG follows and may persist for years following infection. HBsAg is a marker of HBV infection, not immunity.
(6) A patient with multiple myeloma is placed on daratumumab (Darzalex). What tests are affected by this drug, and what are typical recommendations for transfusion?
A. Antibody screen/least incompatible RBCs
B. ABO/washed RBCs
C. Rh/leukocyte-poor RBCs
D. All of the above
A. Antibody screen/least incompatible RBCs
Daratumumab (Darzalex) is a monoclonal antibody directed against CD38, which shows enhanced expression on multiple myeloma tumor cells. Because CD38 is also expressed on RBCs, all screening cells will be positive. The serological workup appears as a warm autoantibody that cannot be resolved with adsorptions and often necessitates the transfusion of least incompatible RBCs.
(7) A unit tests positive for syphilis with use of the rapid plasma reagin (RPR) test. The Treponema pallidum particle agglutination (TP-PA) test on the same unit is negative. What is the disposition of the unit?
A. The unit may be used to prepare components
B. The donor must be contacted and questioned further; if the RPR test result is most likely a false positive, then the unit may be used
C. The unit must be discarded
D. Cellular components may be prepared but must be irradiated before issue
A. The unit may be used to prepare components
This is a case of a false-positive screening test result (RPR). The confirmatory test for treponemal antibodies was negative. The donor unit is acceptable and may be used to prepare blood components.
(8) SITUATION: John Smith donated a unit of whole blood in May. RBCs made from whole blood were transfused to a recipient at a community hospital in June, with no apparent complications. The blood supplier notified the medical director of the hospital that the donor had reported engaging in high-risk behavior with another male in April, although viral tests remain negative and the donor is healthy. What course of action should be taken?
A. No action should be taken
B. The recipient’s physician should be notified
C. The recipient’s physician and the recipient should be notified
D. The recipient should be notified
B. The recipient’s physician should be notified
The recipient’s physician should be notified by the medical director to ascertain the current health status of the recipient, if known, and determine what treatment, if any, the recipient should receive
(9) All of the following are required tests on donor blood, except:
A. HBsAg
B. Anti-CMV
C. HIV-1
D. Anti-HTLV I/II
B. Anti-CMV
Testing of donor blood for antibodies to CMV is not required. However, testing may be done on units intended for transfusion to low-birth-weight infants born to seronegative mothers or units used for intrauterine transfusion; units intended for immunocompromised patients who are seronegative; prospective transplant recipients who are seronegative; or transplant recipients who have received a seronegative organ. Leukocyte reduced RBCs carry a reduced risk of transmitting CMV and are recommended for such patients when CMV testing has not been performed on donor units. The prevalence of anti-CMV in the population ranges from 40% to 90%.
(10) Which of the following bands would constitute a positive Western Blot result for HIV?
A. p24, gp41, p17
B. p55, gp120, p51
C. gp160, p31, p56
D. p24, p30, p55
A. p24, gp41, p17
According to current FDA and CDC criteria, a sample is defined as anti-HIV positive if at least two of the following bands are present on Western blot: p24, gp41, and/or GP120/160.
