267 - Stem Cell Transplantation

Question 1

What is the chance that a sibling is a perfect HLA match?

Answer 1

• 25%
• Can do transplants with half-match (5/10) sibling; preferred over unrelated 8/10 or 9/10

Question 2

What is CAR T-cell therapy?

Answer 2

Take out pt’s stem cells and alter them and put them back in 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

Question 3

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?

Answer 3

Prolonged survival and low mortality associated w/ the transplant

Question 4

MHC class __ activates CD8+ cytotoxic T cells

MHC class __ activates CD4+ cytotoxic T cells

Answer 4

MHC class I activates CD8+ cytotoxic T cells

MHC class II activates CD4+ cytotoxic T cells

Question 5

What are the HLA class I antigens?

Answer 5

HLA-A, B, C

Question 6

When would an allogenic transplant be preferred over an autologus transplant?

Answer 6

1. If we want to use donor graft to fight host leukemia (rare situation where graft vs. host disease is good)
2. If there is something wrong with the patient’s stem cells

Question 7

Why do we asess chimerism after transplantation?

Answer 7

Figure out what percentage of blood cells are derived form donor vs. pt

-> insight as to whether the graft remains viable

Question 8

What can a mulitpotent hematopoietic stem cell differentiatie into?

Answer 8

Any blood cell

Question 9

What is the general order of preference for HSCT donors?

Answer 9

1. Fully matched sibling
2. Fullly matched unrelated
3. Alternative
   
   • Umbilical cord blood (less match required, but not much volume)
   • Half-matched (5/10) related donor
   • Unrelated donor 9/10 or 8/10 if necessary

Question 10

List the key differences between acute and chronic graft vs. host disease

(parts affected, cause, timeline)

Answer 10

• Acute
  
  • Skin, liver, gut
  • Donor T-cells activated by host inflammation from pre-transplant conditioning
  • Within 100 days of stem cell transplant
• Chronic
  
  • Multi-organ
  • Immune dysregualtion, inflammation, fibrosis
  • Within 1-3 years (usually 4-6 months)

Question 11

What is engraftment syndrome?

What is the treatment?

Answer 11

Fevers, rash, diarrhea, pulmonary 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)

Question 12

Why do we perform autologus stem cell transplants?

(What kinds of treatments does it allow for?)

Answer 12

• 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

Question 13

What are the HLA class II antigens?

Answer 13

HLA DR, DQ, DP

In terms of matching importance, DR > DQ > DP