October 2, 2015 - Bone Marrow Transplant Flashcards
Autologous Transplant
Patient’s own cells.
Often gathered by administering growth factors (ie. G-CSF) and/or chemo followed by apheresis of the peripheral blood.
Allogenic Transplant
Using donor cells.
Can also be isolated from umbilical cords.
Complications of Autologous Transplant
Higher relapse rate. This is because of less graft vs tumour effect.
Complications of Allogenic Transplant
Graft versus host disease
Higher treatment-related mortality
Reduced Intensity Conditioning Transplantation
Nonmyeloablative doses of chemotherapy + radiation to immunosuppress patient and allow engraftment of donor stem cells.
Gradual increase in engraftment over months.
This relies on graft vs. disease effect rather than high dose chemotherapy as a major mediator of the effect. Can be performed on patients who can’t undergo normal chemotherapy such as the elderly.
Umbilical Cord Blood Donor
Advantages are that stem cells are already stored, there is no risk to the donor, and there is an increased ability to use mismatched cells (HLA requirements are less strict).
Disadvantages are that there is a lower cell dose for adults, a longer time of engraftment, and higher treatment-related mortality and lower survival compared to matched donor marrow.
Use if it is the only option.
Inheritance of HLA Genes
You get one set from mom and one set from dad.
Siblings have a 25% chance of being a match, however the average number of kids in North America is only 2. Therefore, in reality, this only works in about 30% of people in practicality.
70% of patients will have a full matched donor on the unrelated donor registry, however.
Post-Transplant Complications
Within the first month, usually acute toxicity from chemo or radiation. Can also be graft failure, drug reactions, or infections.
In the next 1-3 months, acute graft vs host disease can occur, along with multiple infections.
From 3-12 months and beyond, chronic GVHD can be a problem, along with relapse.
Anti-Viral Drugs and Transplant
Patients are prophylactically put on anti-virals to prevent outbreaks of dormant viruses such as Varicella zoster, as well as to keep viruses at bay.
Risk Factors for GVHD
HLA mismatch
Unrelated donor
Older age
Female donor to male recipient (pregnancy)
Prevention of GVHD
Immune suppressant drugs are routinely given.
T cell depletion of graft by antibodies against T cells or mechanically removing them out of the graft prior to product infusion.
Treatment of GVHD
Topical steroids
High dose systemic steroids
Additional immune suppression
