Transplantation Flashcards
What is a xenograft?
transplant between members of different species e.g. pig valves
What is an autograft?
transplant from one part of the body to another e.g. skin graft
What is an allograft?
transplant from different members of the same species
What is the major transplant antigen?
MHC
What are the 3 types of rejection?
antibody mediated rejection, acute allograft rejection and chronic allograft rejection
What is an antibody mediated rejection?
rejection in minutes to hours due to preformed antibodies to blood group or MHC
How can you predict if an individual will have antibodies against MHC?
if they’ve had a previous blood transfusion, pregnancy or transplant - however sometimes happens even without any of these conditions
What is an acute allograft rejection?
rejection that happens from days to weeks - as immune cells pass through the transplanted organ it will recognise non self proteins and present these to the T cels in the lymph nodes - the T cells will be activated and proliferate and start an immune response against the organ
How is an acute allograft rejection diagnosed?
biopsy organ and look for presence of T cells
What is a chronic allograft rejection?
rejection that happens over months to years - cause is not well understood - related to many low level injuries such as ischaemia reperfusion injury, infections, high BP, acute cellular rejection etc. - characterised by scarring or fibrosis of the organ
How do you prevent an allograft rejection?
transplant down blood group line, try and match MCH alleles, immunosupressive drug
What drugs are given post transplant?
a combination of azathioprine, glucocoritosteroid and cyclosporin/tacrolimus
What is the action of cyclosporin/tacrolimus?
inhibits transcription of IL-2 so selectively targets recently activated T cells
What are the side effects of cyclosporin/tacrolimus?
prone to viral infections, causes kidney damage
What is the action of azathioprine?
anti-prolifeartive - non specifically inhibits DNA and RNA synthesis
