transplantation Flashcards
What are the 2 main barriers in transplantation
Rejection (immune response against the donor organ)
Tissue availability (organ donor shortage)
What are the 4 types of grafts in transplantation
Autograft (same individual)
isograft(identical service)
allograft(same species,different individuals)
xenograft(different species)
what are the 3 types of transplant rejection
Hyper acute- minutes to hrs
acute-days to weeks
chronic-months to years
what causes hyperacute rejection
preexisting antibodies against donor antigens
how is acute rejection mediated
by t cells recognising foreign MHC molecules and attacking the transplanted organ
what is chronic rejection charactrised by
fibrosis
vascular damage
gradual loss of organ function
what is the role of MHC in transplant rejection
MHC molecules present donor antigenns to reciept t cells triggering immune response
How does HLA matching help in transplantation
Closer HLA matching reduces the risk of immune rejection
what are the two immune pathways involved in rejection
direct pathways-donor apcs activate recipient t cells
indirect pathways -recipient apcs process donor antigens
name 3 classes of immunosuppressive drugs used in transplantation
Calcineurin inhibitors -cyclosporine
corticosteriods
monoclonal antibodies
What are potential solutions to the organ donor shortage
Xenotransplantion - animal organs
animal chimeras - genetically engineered animals for human compatible organs
WHat is the most common allograft transplantation
Corneal transplantation
What is Graft - versus -host disease
GHVD occurs when donor immune cells attack the recipients tissues ,mainly in hematopoietic stem cell transplantation
What are the main sources for haemopoietic stem cell transplantation
Bone marrow ,peripheral blood and umbical cord
What are some future directions in transplantation
Improves immunosupressive therapies ,bioenginnered organs and better HLA matching techniques
