TRANSPLANT REJECTION Flashcards
When does hyper acute rejection occur?
Within minutes to hours
What causes hyper acute rejection?
Pre-existing antibodies against ABO or HLA antigens leads to widespread thrombosis of graft vessels = ischaemia and necrosis of transplanted organ
What type of hypersensitivity reaction is hyper acute rejection?
Type 2
Whats the management for hyper acute rejection?
No treatment is possible and the graft must be removed
When does acute graft failure occur?
Within 6 months
What causes acute graft failure?
Mismatched HLA or inadequate immunosuppression
It’s caused by cytotoxic T cells
How is acute graft failure managed?
Steroids and immunosuppressants
What can multiple episodes of acute graft failure cause?
Chronic graft failure
When does chronic graft failure occur?
Usually after 6 months
What causes chronic graft failure?
Antibody and cell-mediated mechanisms cause fibrosis
Or recurrence of original disease
What is induction therapy?
immunosuppressive therapy administered at the time of kidney transplantation to reduce the risk of allograft rejection
What is used as induction therapy in the UK?
Basiliximab
Rabbit anti-human thymocyte immunoglobulin
What is used as maintenance therapy?
Tacrolimus
Belatacept
Mycophenolate
Sirolimus
Everolimus
Whats the moa of Ciclosporin?
Inhibits calcineurin (a phosphotase involved in T cell activation)
Whats the moa of tacrolimus?
Inhibits calcineurin
Whats the moa of mycophenolate?
Blocks purine synthesis and so inhibits proliferation of B and T cells
Whats the moa of sirolimus?
Blocks T cell proliferation by blocking IL-2 receptor
What should patients on long term immunosuppression for organ transplantation be monitored for?
CVD
Renal failure
Malignancy
Why are patients on long term immunosuppression for organ transplantation at risk for CVD?
Tacrolimus Ciclosporin can cause hypertension, hyperglycaemia and tacrolimus can also cause hyperlipidaemia
Why are patients on long term immunosuppression for organ transplantation at risk for renal failure?
Tacrolimus and Ciclosporin have nephrotoxic effects
What malignancy are patients at risk for when on long term immunosuppression for organ transplantation?
Squamous cell and basal cell carcinomas
25% of patients who live for 20 years after a transplant develop some type of cancer
