transplantation Flashcards
most common organ and tissue transplanatation in UK
organ= kidney
tissue= cornea and HSC
types of transplants by donar and recipient
1) autologous
2) syngeneic
3) allogenieic
4) xenogeneic
1) from same individial
2) from genetically identical people e.g. twins
3) same species human to human
4) from animal to human
types of transplant by tissue and organ
1) immune privilleged sites
2) vascularied solid organs
3) HSC
4) skin
1) cornea : allogeneic
2) allogeniec
3) allogeneic and autologous
4) allogeneic and autologious
why transplant rejection occurs
-ABO
-HLA (human leukocyte antigen)
-different blood group
-genetic diffrence between people
difference between HLA1 and HLA2
1= all nucleated cells. present to antigen CD8
2= antigen presenting cells. present to CD4
what is HLA and why does it vary between people
most polymorphic region of the human genome
why= so population immune response to pathogens varies so the population can survive
HLA matching for transplantation
-what tranplant is it more important for
the more alike the HLA types the more transplant will be successful
-most important for bone marrow ect. than cornea
for cornea (HLA matching has no effect)
importance to screen donor and recipient prioir to transplantation
1) identifying genetic variations between donar and recepit
2) identifying pre-existing antibodies (anti-HLA) against donar cells
1) ABO blood test and HLA typing
2) cytotoxic cross matching
-donar specifc antibody screening
stages of draft rejection
1) hyper acute
2) accelerated acute rejection
3) acute rejection
4) chronic rejection
1) takes minutes to hours. antigens completely unmatched
2) 3-7 days. sensitised memory T cells, by prvious pregancy, blood tranfusion…
3) after a week. due to activation of T cells
4) occurs after years, due to antibody rejection
how to minimise graft rejection
drugs by immunosuppression
