Cord Blood Cord Blood Stem Cells 1 — Questions and Answers
Question 1: What type of stem cells are primarily found in cord blood that give rise to all blood and immune cells?
- Hematopoietic stem cells (Correct answer)
- Embryonic stem cells
- Induced pluripotent stem cells
- Adipose-derived stem cells
Correct answer: Hematopoietic stem cells
Cord blood is rich in hematopoietic stem cells (HSCs), which are multipotent progenitors capable of regenerating the entire blood and immune system.
Question 2: Which surface marker is most commonly used to identify and quantify hematopoietic stem cells in cord blood?
- CD3+
- CD34+ (Correct answer)
- CD19+
- CD56+
Correct answer: CD34+
CD34+ is the primary surface antigen used to identify hematopoietic stem and progenitor cells in cord blood units.
Question 3: Compared to bone marrow stem cells, cord blood stem cells have which key proliferative advantage?
- Shorter telomeres
- Longer telomeres and higher self-renewal capacity (Correct answer)
- Lower CD34+ concentration
- Greater susceptibility to apoptosis
Correct answer: Longer telomeres and higher self-renewal capacity
Cord blood stem cells have longer telomeres than adult bone marrow stem cells, giving them superior self-renewal capacity and proliferative potential.
Question 4: What does 'engraftment' mean in the context of a cord blood transplant?
- Rejection of the donor cells by the recipient
- Successful establishment of donor stem cells in the recipient's bone marrow (Correct answer)
- Freezing of cord blood for storage
- Removal of red blood cells from cord blood
Correct answer: Successful establishment of donor stem cells in the recipient's bone marrow
Engraftment occurs when transplanted donor stem cells successfully home to the recipient's bone marrow and begin producing new blood cells.
Question 5: Why do cord blood T-cells cause less graft-versus-host disease compared to adult donor T-cells?
- Cord blood has no T-cells
- Cord blood T-cells are naive and less alloreactive (Correct answer)
- Cord blood T-cells produce more interferon-gamma
- Cord blood T-cells are fully activated at birth
Correct answer: Cord blood T-cells are naive and less alloreactive
Cord blood T-cells are immunologically naive and have reduced alloreactivity, which is why cord blood transplants are associated with lower rates of severe GVHD.
Question 6: Which colony-forming unit assay is used to assess the functional potency of hematopoietic progenitors in a cord blood unit?
- CFU-GM assay (Correct answer)
- ELISA assay
- PCR assay
- Flow cytometry only
Correct answer: CFU-GM assay
The CFU-GM (colony-forming unit granulocyte-macrophage) assay measures the ability of cord blood progenitors to form colonies in culture, indicating functional potency.
Cord Blood Cord Blood Stem Cells 1
What type of stem cells are primarily found in cord blood that give rise to all blood and immune cells?