Transplant Medicine

Question 1

Stem Cell Sources

Answer 1

Autologous - patient’s own stem cells (possible if marrow is unaffected)
Syngeneic - genetically identical twin (not useful for genetic defects)
Allogeneic - partially/fully matched HLA donor (most common)

Question 2

Allogeneic Source Order of Preference

Answer 2

1) matched sibling
2) matched and unrelated
3) umbilical cord blood stem cells
4) partially matched and unrelated
5) haploidentical (half-match donor, immunosuppressors required)

Question 3

HLA matching

Answer 3

10 HLA genes are considered when matching

there are other HLA genes, this is why sibling matches are better than 10/10 unrelated match

Question 4

Peripheral blood stem cell harvest

Answer 4

administer granulocyte colony stimulating factor
neutrophil and stem cell growth stimulated
extract stem cells via blood pheresis

Question 5

Range of intensity for transplant preparative regimines

Answer 5

Myeloablative - highly ablative of marrow, kills many cells
Reduced intensity - less ablative of marrow cells
Non-myeloablative - marrow recovers with mixed chimerism

Question 6

For non-malignancies, what intensity of transplant preparation is best?

Answer 6

Non-myeloablative (lowest intensity)
eg. Hurler syndrome, sickle cell anemia

Don’t need to kill 100% of marrow, less-intense is better

Question 7

For leukemia, what intensity of transplant preparation is best?

Answer 7

myeloablative (highest intensity)

want to wipe out all cancerous cells

Question 8

Why administer chemotherapy/radiation before a bone marrow transplant?

Answer 8

Suppress the immune system
Clear space for new cells
Treat the malignancy

Question 9

What is the major limitation of umbilical cord blood stem cells as a source for bone marrow transplant?

Answer 9

Low number of cells