Haematology 15 - Bone Marrow Transplant Flashcards
Which CD marker is expressed on haematopoietic stem cells?
CD34
Recall the process of autologous transplant
- Give G-CSF - lots of stem cells leak out from bone marrow into the blood
- Freeze them (drop temp and store in liquid N2)
- Patient has chemo/radio to permanently destroy their haematopietic system
- Whip stem cells out of freezer and re-infuse
What is autologous stem cell transplant used for?
To allow a higher dose of chemo/radio to be given
Biggest use in: Myeloma/ lymphoma/ CLL
*these patients don’t have much reserve for allogeneic stem cell transplant
Describe the process of allogeneic stem cell transplant
Give G-CSF to DONOR with normal BM
Treat patient with high-dise chemo and radio
Give patient harvested cells
When should allogenic stem cell transplant be used?
Bone marrow failure - because in autologous need a functioning bone marrow
Any patient where bone marrow can’t be cleared (eg acute leukaemias)
How is patient’s room pressure adjusted to prevent infection during BM transplant?
Make it a higher pressure than corridor so that air flows out rather than in
Recall some principles of donor choice for a bone marrow transplant
- HLA-matched
- Ideally a sibling (1 in 4 chance of matching with each sibling)
Which patients can receive umbilical cord blood cells?
Only children - as you can only harvest a small volume so patient needs to be of a low weight
How many types of HLA are there?
>20,000!
What are the two classes of HLA molecules?
Class I: HLA A, B C
Class II: HLA DP, DQ, DR
Which HLA types do we routinely match for?
HLA-A, B
HLA DR
DR A B
What are the complications of stem cell transplant?
- graft failure - not very common
- infections
- graft vs host disease
- relapse
What happens in graft versus host disease?
GRAFT attacks HOST
Donor immune system recognises patient as foreign
Mounts an immune response
This happens because when you kill cancer cells with chemo, the dying cells release a lot of cytokines
So when you insert donor cells, the lymphocytes get attracted to cytokines–>stimulate the immune system
Acute vs chronic graft vs host disease
Acute (first 3 months): skin, GI tract and liver
Chronic: skin, mucosal membranes, liver, lungs, joints, eyes - it’s like scleroderma
What is staging and grading of GVHD based on?
Extent to which the following are affected:
a) skin
b) liver
c) GI tract
Risk factors for acute GVHD
older age
conditinoing regimen- blood is worse than bone marrow
female donor, male recipient
disease phase- more aggressive
viral ifnections
Treatment of acute GVHD
Prevention of acute GVHD
Risk factors for chronic GVHD
Which is the strongest prognostic factor?
same as acute
and also previous acute GVHD
^strongest prognostic factor
After transplant which infections are most common: bacterial, viral or fungal?
Bacterial
With time, viral
Fungal - can affect anytime
What are the sources of bacterial infections post transplant?
Gram positive: vascular access
Gram negative: gastrointestinal access
How can CMV reactivation manifest in immunosuppressed patients?
