Renal transplantation Flashcards
What are the two major determinants of transplant suitability in terms of graft rejection?
ABO blood group and HLA matching
Why can a person with blood group O only receive a kidney from another person with blood group O?
These patients have antibodies against A and B antigens
What are HLAs, and what are the three most important?
Human leucocyte antigens- expressed on cells, can activate the immune system.
HLA-A, HLA-B, HLA-DR
Describe the immunopathology of transplant rejection.
HLA antigens are expressed by MHC on antigen presenting cells; activate B cells and CD8 cells via exposure to CD4 T-helper cells.
How are hyper-acute and acute rejection distinguished?
Hyper-acute is within minutes, due to preformed antibodies to the transpland (unsalvageable).
Acute- due to B-cell and T-cell response. Can be treated with increased immunosuppression.
Give examples of calcineurin inhibitors and explain how they function as immunosupppressive agents.
Cyclosporin, tacrolimus.
Inhibit activation of T-helper cells.
How azathioprine and mycophenolate work? What are the possible side effects?
Inhibit purine synthesis; suppress the proliferation of B cells. Anaemia, leucopenia, GI side effects
Which drug should azathioprine never be given with?
Allopurinol (interaction causes a drastic decrease in white cell count)
What are the main types of donor kidney?
Deceased brain dead (allocated nationwide)
Deceased cardiac death (usually used locally)
Live donor (usually related but spousal also common)
How is suitability for transplant determined?
Life expectancy of at least 5 years
Based on tissue typing THEN time spent on list
Should not get cadaveric transplant more than 6 months before starting haemodialysis
What are the absolute contraindications to transplant?
Severe IHD
Known untreated malignancy (or solid tumour within last 2 years)
Severe peripheral vascular disease (unusable vessels)
Untreated TB
Severe airways disease
Active vasculitis
How do you know whether the transplant is working?
Falling urea and creatinine
In delayed graft function how long does it normally take before the transplant begins functioning?
10-30 days- need HD in interim
How can a graft be lost?
Chronic rejection
Recurrent disease
Ischaemia
Cyclosporin/tacrolimus toxicity
What are the possible complications of transplant?
Rejection (acute or chronic) Infection/malignancy due to immunosuppression Atheromatous vascular disease Hypertension Drug toxicity
