Cord Blood Cord Blood Transplantation 1 — Questions and Answers
Question 1: What conditioning regimen is administered to patients before a cord blood transplant and why?
- Antibiotics to prevent infection only
- High-dose chemotherapy and/or radiation to destroy diseased marrow and make space for donor cells (Correct answer)
- Low-dose corticosteroids to reduce inflammation
- Blood transfusions to boost cell counts
Correct answer: High-dose chemotherapy and/or radiation to destroy diseased marrow and make space for donor cells
Myeloablative or reduced-intensity conditioning regimens use high-dose chemotherapy and/or total body irradiation to eradicate diseased cells and suppress the immune system to allow donor stem cell engraftment.
Question 2: What is the typical time to neutrophil engraftment following a cord blood transplant compared to bone marrow transplant?
- Faster at 7–10 days
- Similar at 10–14 days
- Slower at 21–28 days or more (Correct answer)
- Immediate within 24 hours
Correct answer: Slower at 21–28 days or more
Neutrophil engraftment after cord blood transplant typically takes 21–28 days or longer, compared to 14–21 days for bone marrow, due to the lower cell dose in cord blood.
Question 3: What is double cord blood transplantation (dCBT)?
- Using two units of cord blood from the same donor
- Infusing two unrelated cord blood units to increase cell dose for adult recipients (Correct answer)
- Performing two separate transplants one year apart
- Mixing cord blood with bone marrow
Correct answer: Infusing two unrelated cord blood units to increase cell dose for adult recipients
Double cord blood transplantation involves infusing two separate, unrelated cord blood units simultaneously to achieve a higher total cell dose adequate for adult patients.
Question 4: What does HLA (Human Leukocyte Antigen) matching refer to in cord blood transplantation?
- Matching blood types between donor and recipient
- Matching immune recognition proteins between donor and recipient to reduce rejection risk (Correct answer)
- Matching the volume of cord blood units
- Matching the age of the donor and recipient
Correct answer: Matching immune recognition proteins between donor and recipient to reduce rejection risk
HLA matching compares specific immune system proteins on cell surfaces between donor and recipient, with closer matches associated with lower rates of rejection and GVHD.
Question 5: Which HLA loci are typically evaluated when selecting a cord blood unit for transplant?
- HLA-A, HLA-B, and HLA-DRB1 (Correct answer)
- HLA-C and HLA-E only
- HLA-G and HLA-F only
- Only blood group ABO
Correct answer: HLA-A, HLA-B, and HLA-DRB1
Cord blood units are most commonly matched at HLA-A, HLA-B (at antigen level), and HLA-DRB1 (at allele level) for a 6/6 match, with 4/6 considered the minimum acceptable.
Question 6: What is primary graft failure in cord blood transplantation?
- GVHD occurring within 14 days
- Failure of donor stem cells to engraft and produce blood cells within the expected timeframe (Correct answer)
- Bacterial infection following transplant
- Relapse of the original disease
Correct answer: Failure of donor stem cells to engraft and produce blood cells within the expected timeframe
Primary graft failure occurs when transplanted cord blood stem cells fail to engraft and produce sustained blood cell production, often due to insufficient cell dose or immunological rejection.
Cord Blood Cord Blood Transplantation 1
What conditioning regimen is administered to patients before a cord blood transplant and why?