Haematology - Bone Marrow Transplant

Question 1

Which CD marker is expressed on haematopoietic stem cells?

Answer 1

CD34

Question 2

Recall the process of autologous transplant

Answer 2

1. Give G-CSF - lots of stem cells leak out into the blood
2. Freeze them (drop temp and store in liquid N2)
3. Patient has chemo/radio to permanently eradictae/destroy their haematopietic system
4. Whip stem cells out of freezer and re-infuse

Question 3

What is autologous stem cell transplant used for?

Answer 3

To allow a higher dose of chemo/radio to be given
Myeloma/ lymphoma/ CLL

Question 4

Describe the process of allogeneic stem cell transplant

Answer 4

Give G-CSF to donor with normal BM
Treat patient with high-dose chemo and radio
Give patient harvested cells

Question 5

When should allogenic stem cell transplant be used?

Answer 5

Bone marrow failure
SCD
Thalassemia
Any patient where bone marrow can’t be cleared (eg acute leukaemias)

Question 6

How is patient’s room pressure adjusted to prevent infection during BM transplant?

Answer 6

Make it a higher pressure than corridor so that air flows out rather than in

Question 7

Recall some principles of donor choice for a bone marrow transplant

Answer 7

1. HLA-matched
2. Ideally a sibling (1 in 4 chance of matching with each sibling)

Question 8

Which patients can receive umbilical cord blood cells?

Answer 8

Therefore, in cord blood (only harvest 0.1L), there is fewer CD34 cells and so can only really be used for babies

Question 9

How many types of HLA are there?

Answer 9

>20,000!

Question 10

autologous vs allogeneic

Answer 10

The stem cells in autologous transplants come from the same person who will get the transplant, so the patient is their own donor.

The stem cells in allogeneic transplants are from a person other than the patient, either a matched related or unrelated donor.

Question 11

what is the likelihood of a sibling being a match

Answer 11

= 1-(3/4) ^ number of siblings
the more siblings, the greater the chance of finding a fully identical matching sibling.

Question 12

what is graft versus host disease

Answer 12

an immune response when the donor cells recognise the patient as foreign

Question 13

what tool to calculate outcome of transplant

Answer 13

EBMT risk score:
age of the patient, disease stage, time from diagnosis to transplantation, donor type, and donor–recipient sex combination
higher score = less chance of successful outcome
note (Donor: Male , R: F get worse GvHD)

Question 14

outline 5 treatment option in GvHD

Answer 14

Corticosteroids
Cyclospiorin A
Tacrolimus (FK506)
Mycophenolate motefenil
Monoclonal antibodies

Question 15

what is the difference in aims of autologous and allogeneic HSCT?

Answer 15

Autologous HSCT = goal to kill all leukaemia with radio/chemo
Allogenic HSCT = accepted you cannot kill leukaemia from radio/chemo, rely on BM from donor

Question 16

give 3 sources where stem cells can be harvested? which has the highest yield

Answer 16

bone marrow sampling - (1.5L, 1% CD34+ = 15mL CD34)
peripheral blood sampling - (10L, 1% CD34+ = 100mL CD34)
umbilical cord stem cells - (0.1L, 1% CD34+ = 1mL CD34)

note of all the methods of harvesting, CD34+ stem cells will only make up about 1% of the sample

important because success of transplant depends on the number of CD34 cells per kg of weight of the recipient