Bone marrow transplantation Flashcards
- Describe how autologous transplant occurs
- Which conditions are autologous transplant useful for?
- Growth factor is given to the patient
- Stem cells are collected and frozen
- The stem cells can then be thawed and reinfused when the patient needs them e.g. recieving high dose chemotherapy
Autologous stem cell transplant is when the patient recieves their own stem cells
- Acute leukemia, solid tumors, autoimmune diseases, - anything that you can treat into complete remission
Can be used inmyeloma, lymphoma and CLL as a holding therapy but not a cure
- What is allogenic transplant?
- What are it’s uses?
- Allogenic transplant is when stem cells/bone marrow is donated from a donor
- Suitable for when someone undergoes high dose chemotherapy +/- radiotherapy. Can be used for
- Acute leukemia
- Chronic leukemia
- Myeloma
- Lymphoma
- BM failure
- Congenital immune deficiencies
- Which organ in the body is most susceptible to radiation?
- Which organ is the least susceptible to radiation?
- Bone marrow
- CNS
What marker which is found on the surface of a human stem cell can be used to identify a stem cell?
CD34
How do we choose a donor for stem cell transplantation?
Someone who is a well-matched tissue type or HLA type. Ideally a sibling, and if not an unrelated donor with a close match
Describe the process of transplantation
Identify disease unlikely to respond to standard treatment
Treat patient to remission
Identify a donor and collect stem cells
Give patient myeloablative therapy - need to remove the current immune system
Infuse stem cells
Continue immunosuppression & support patient through period of cytopenia - to prevent graft vs host disease
Which chromosome is HLA encoded for?
Short arm of chromosome 6
- What do HLA class 1 present to?
- What do HLA class 2 present to?
- HLA class one presents to CD8+ cytotoxic T-lymphocytes
- HLA class 2 presents to CD4 Helper T cells
HLA -A2 alleles. There are several types of HLA-A2, but what are the two genes that are most common that all lineages of HLA-A2 have?
- G62
- T142-H145
Why would you not want to transfuse someone who A*0201 with someone who is A*0205, even when they are both HLA-A2 positive?
Becuase although these subtypes of HLA-A2 have matching genes within them e.g. G62. Individually they have mismatches in their sequences which are unique to them, and these can be recognised by T cells and produce varying levels of graft vs host disease
So even though they are both HLA-A2 matching, there are subtypes within HLA-A2 which makes them less similar, and these can be detected by T cells
What three places can stem cells be harvested from?
Bone marrow
Peripheral blood
Umbilical cord
What amount of CD34 cells are needed per kilo of body weight for transplant to be successful?
2x106 CD34+ cells per kilo of body weight minimum
What are the complications of stem cell transplant?
- Graft failure
- Infections
- Graft versus host disease - allografting only
- Relapse
What 5 things affects the outcome of transplant?
Age <20=0,20-40=1,>40=2
Disease phase Early=0, int=1, late=2
Gender of R/D Female into male = 1
Time to BMT <1 yr = 0, >1 yr = 1
Donor Sib = 0, VUD = 1
High score is bad, and can help predict 5 years survival
What does the cell need to be doing to be targeted by chemotherapy?
Chemotherapy will target any cell that it is dividing. Therefore, it will also target healthy cells that rapidly divide e.g. in the GI tract, epithelial cells in the lung, sperm etc.
