Transplantation Flashcards
What blood type is the universal acceptor?
AB
Why do antibody-mediated rejections occur so fast?
The antibody is already there
Which individuals are more likely to get antibody rejections?
Those who’ve had blood transfusion, pregnancies or previous transplants (previous exposure to different MHCs)
Who performed the first kidney transplant?
Joseph Murray
What is advantageous about using a combination of immunosuppressive drugs?
You can use small doses of each to reduce side effects
Which blood type is the universal donor?
O
What are the 3 types of rejections?
Hyper-acute aka antibody-mediated rejection
Acute
Chronic
What are three ways of preventing graph rejection?
Match blood group
Match MHC
Immunosuppressive drugs
What pathological process occurs in chronic rejection of kidney transplants?
Fibrosis and scarring > Intimal fibrosis > Loss of tubules
What is the current direction of transplant research?
Better immunological matching
More specific immunosuppression
Xenotransplantion
Induction of tolerance
Stem cell transplantation
What is the mechanism of action of azathioprine?
Inhibition of cell proliferation
What is the difference between an allograph and an isograph?
An isograph is from a genetically identical person
An allograph is from a genetically different person from the same species
What immune cell is responsible for rejection?
T cells
Why is cyclosporin an more selective immunosuppressor?
It targets recently activated T cells
How do calcineurin inhibitors downregulate activated T cells?
Downregulate expression of IL-2
How is inflammation amplified in antibody-mediated rejection?
Antibodies bind to the donor MHC which initiates complement
Which molecule is the major driver of graph rejection?
MHC
What three drugs are used in the immunosuppression cocktail?
Anti-inflammatory eg steroids
Anti-proliferative eg azathioprine
Calcineurin inhibitors eg cyclosporin
What was the original immunosuppressive drug used in transplants?
Azathioprine
What are some risk factors for the development of chronic rejection?
Episodes of acute rejection
Ischaemia/reperfusion
Dyslipidaemia
Infection
Hypertension
What infections do calcineurin inhibitors leave you prone to?
Viral
What is another calcineurin inhibitor apart from cyclosporin?
Tacrolimus
Why is it harder to MHC match lung and heart transplants?
There are less donors available and less time
Which chromosome encodes MHC?
6
What is the mechanism for acute rejection?
T cell activation against donor ag’s > T cell mediated response
How do anti-proliferative drugs work?
Inhibit RNA and DNA synthesis
Block IL-2 synthesis and T cell expansion