transplant Flashcards
graft vs host problem
problem, t cells from donor to recipient. need to get past to open up option and not have to try regrowing our own organs
to change blood types:
add on chemical groups to carbohydrate to o
hyperacute rejection of a kidney or new organ is :
type 2 hyper sensitivity reaction, if mom is Rh- and child is Rh+
transplant rejection is a:
type 4 hypersensitivity reaction dealing with direct or indirect
most all drugs in transplant target:
direct and indirect allorecognition, related to t cells
when recipient t cells recognize the donor cells, that is:
direct allorecognition (tcells recognize the foreign hla peptide directly)
when recipient apcs take up parts of the graft and present it to t cells, it’s called:
indirect allorecognition
syngeneic graft:
identical twin
allogeneic graft:
members of same species (mice, white graft on black mouse will be rejected)
xenogeic graft
between different species (pigs and humans)
transplant rejection is an _____, characterized by ______ and specificity so:
immunologic reaction, immunologic memory, the rejection is faster each time
during t cell training, your t cells are made to recognize, ____ but ____ will stimulate them
your own HLA molecules, someone else’s HLA molecules will stimulate yours QUICKLY
graft rejection is due to ______
recipient immune response against MHC major and minor antigen
foreign HLA and minor HLAare called:
alloantigens (this is with the peptide)
mechanisms of rejection:
acute very quickly, chronic is late (direct recognition)
how do you determine if a transplant is a match?
mixed lymphocyte reaction MLR (irradiate, keep from dividing, donor cells can’t divide),
a sign that there will be rejection?
T cell proliferation
Ricipient t cells recognize:
donor HLA in an acute rejection through direct allorecognition (will be on test) it’s the bun!
foreign HLA:
strongly stimulate recipient t cells
indirect allorecognition
donor dendritic cell is dying, it’s taken up by the host apc (dendritic cell) it’s the hotdog-peptide
hyperacute rejectino
due to circulating abo or hla antigens, occurs within 48 hours after transplant and results in complement activation
acute rejection
response to foreign HLA histocompatability antigens, occurs 7-10 days after or 6-12 months mediated by cytotoxic t cells, macrophages and antibodies
chronic rejection
response to minor hisocompatability antigens, may occur several years following transplant and involves Th 1 cells
how do you stop rejctions? ON TEST
cyclosporin A, corticosteroids, anti-cd3 monoclonal antibodies
