267 - Stem Cell Transplantation Flashcards
What is the chance that a sibling is a perfect HLA match?
25%
Can do transplants with half-match (5/10) sibling; preferred over unrelated 8/10 or 9/10
What is CAR T-cell therapy?
Take out pt’s stem cells and alter them so that they can recongize and fight malignancy
- Use a virus to transduce cells with anti-CD19 CAR (chimeric antigen receptor)
- -> T cells are dialed into CD19+ B-cell malignancy when transfused back to pt
If a patient has high-risk melanoma with a good response to chemotherapy, why would we also want to do an autologous stem cell transplant?
Prolonged sruvival
Low non-relapse mortality
MHC class __ activates CD8+ cytotoxic T cells
MHC class __ activates CD4+ cytotoxic T cells
MHC class I activates CD8+ cytotoxic T cells
MHC class II activates CD4+ cytotoxic T cells
What are the HLA class I antigens?
HLA-A, B, C
When would an allogenic transplant be preferred over an autologus transplant?
- If we want to use donor graft to fight host leukemia (rare situation where graft vs. host disease is good)
- If there is something wrong with the patient’s stem cells
Why do we asess chimerism after transplantation?
Figure out what percentage of blood cells are derived form donor vs. pt
-> insight as to whether the graft remains viable
What can a mulitpotent hematopoietic stem cell differentiatie into?
Any blood cell
What is the general order of preference for HSCT donors?
- Fully matched sibling
- Fullly matched unrelated
- Alternative
- Umbilical cord blood (less match required, but not much volume)
- Half-matched (5/10) related donor
- Unrelated 9/10 ro 8/10 if necessary
List the key differences between acute and chronic graft vs. host disease
(parts affected, cause, timeline)
- Acute
- Skin, liver, gut
- Donor T-cells activated by host inflammation from pre-trnasplant conditioning
- Within 100 days of stem cell transplant
- Chronic
- Multi-organ
- Immune dysregualtion, inflammation, fibrosis
- Within 1-3 years (usually 4-6 months)
What is engraftment syndrome?
What is the treatment?
Fevers, rash, diarrhea, pulonary infiltrates as the graft begins to take
Associated with growth factors given to shorten the neutropenic window
Tx = steroids (but try to keep them minimal; pt is already immunosuppressed)
Why do we perform autologus stem cell transplants?
(What kinds of treatments does it allow for?)
Harvest stem cells before chemo
Allows for high-dose chemo for specific blood cancers
Rescued by own stem cells = can grow back original bone marrow
What are the HLA class II antigens?
HLA DR, DQ, DP
In terms of matching importance, DR > DQ > DP