CTBS Donor Screening & Eligibility 3 — Questions and Answers
Question 1: Which of the following serological testing results would render a tissue donor ineligible under FDA regulations regardless of other findings?
- Repeatedly reactive HIV-1 NAT (Correct answer)
- Borderline-reactive RPR with a negative TPPA confirmatory test
- Single reactive HBsAg with a negative confirmatory neutralization test
- A low-level HTLV-I/II antibody that is negative on repeat testing
Correct answer: Repeatedly reactive HIV-1 NAT
A repeatedly reactive HIV-1 NAT result confirms viral nucleic acid presence and is an absolute contraindication for tissue donation.
Question 2: For tissue donors who die from drowning, which of the following is a primary concern related to blood specimen integrity?
- Hemodilution may compromise serological test accuracy (Correct answer)
- Cold water exposure elevates false-positive syphilis titers
- Saltwater exposure causes false-positive HCV NAT results
- Drowning increases HTLV antibody reactivity
Correct answer: Hemodilution may compromise serological test accuracy
Hemodilution from fluid resuscitation or drowning can dilute antibody concentrations below assay detection thresholds, potentially yielding false-negative serology.
Question 3: A tissue donor received 2 units of packed red blood cells 24 hours before death. Which step is required before determining serological test validity?
- Apply a hemodilution algorithm to assess specimen dilution (Correct answer)
- Repeat all serology on a post-transfusion specimen only
- Automatically disqualify the donor from all tissue donation
- Obtain a pre-transfusion specimen from the hospital blood bank
Correct answer: Apply a hemodilution algorithm to assess specimen dilution
AATB standards require applying an FDA-accepted hemodilution algorithm to determine whether transfusion compromised specimen integrity before accepting serological results.
Question 4: Cytomegalovirus (CMV) serology is routinely tested in tissue donors primarily to:
- Provide CMV status information to guide recipient selection by transplant physicians (Correct answer)
- Disqualify all CMV-seropositive donors from tissue donation
- Fulfill an FDA mandatory testing requirement under 21 CFR 1271
- Detect active CMV viremia using NAT
Correct answer: Provide CMV status information to guide recipient selection by transplant physicians
CMV serology is used to inform transplant physicians about donor CMV status so they can match donors and recipients appropriately, especially for immunocompromised patients.
Question 5: Under AATB standards, a tissue bank receives a donor specimen with a repeatedly reactive HBsAg result. The neutralization confirmatory test is negative. The donor should be:
- Considered ineligible because HBsAg was repeatedly reactive regardless of confirmatory result (Correct answer)
- Eligible because the confirmatory test was negative
- Eligible only for corneal donation
- Eligible after a 6-month quarantine period
Correct answer: Considered ineligible because HBsAg was repeatedly reactive regardless of confirmatory result
Per FDA and AATB standards, a repeatedly reactive HBsAg screening test result renders the donor ineligible, even if a supplemental test is negative.
Question 6: Nucleic acid testing (NAT) for tissue donors offers the primary advantage of:
- Detecting HIV and HCV during the window period before antibody development (Correct answer)
- Eliminating the need for serological antibody testing
- Providing quantitative viral load measurements for clinical use
- Identifying all strains of HTLV
Correct answer: Detecting HIV and HCV during the window period before antibody development
NAT shortens the window period by detecting viral genetic material before the immune system produces detectable antibodies, reducing the risk of false-negative results.
Question 7: A tissue bank procuring a donor who died outside the US must ensure that infectious disease testing is performed using:
- FDA-licensed or -approved test kits, or tests approved by an equivalent regulatory authority (Correct answer)
- Only WHO-approved assays regardless of test availability
- The same laboratory used for the donation, with no substitutions
- Any commercially available test validated for serum specimens
Correct answer: FDA-licensed or -approved test kits, or tests approved by an equivalent regulatory authority
FDA regulations require that testing be performed with FDA-licensed, -cleared, or -approved assays, or their equivalents from recognized regulatory authorities for international donors.
CTBS Donor Screening & Eligibility 3
Which of the following serological testing results would render a tissue donor ineligible under FDA regulations regardless of other findings?