Transplantation Flashcards
What gene is responsible for the rejection/acceptance of a tissue graft?
the MHC gene
what locus in the MHC gene is most important in tissue transplantation?
HLA-DR locus
what lymphocyte does the killing of the graft?
CTL (CD8+)
What is a Hyper acute graft rejection?
when you have pre-made antibodies that recruit complement leading to tissue necrosis
What is a Acute graft rejection?
when CD8+ destroy the graft
What is a Chronic graft rejection?
when there is both a humoral and cell-mediated response against the graft
what is direct alloantigen recognition?
when T cells bind directly to a intact allogenic MHC molecule on a graft APC
what is indirect alloantigen recognition?
when the MHC of the graft is taken up by host APC’s and processed into peptides
what is Mixed Lymphocyte Reaction?
it is used to identify class MHC 2 antigen between the donor and the host
what technique is used to identify the host and donors MHC 1 and 2 chromosomes?
HLA-Typing
what immunosuppression drug works best for transplantation?
cyclosporin and FK506
what drug for immunosuppression will work inhibiting guanine?
mycophenolate
what type of graft is never rejected?
synergistic grafts
when does graft rejection usually occur?
in 10 days
when does a 2nd graft usually get rejected?
in 1 week
will MHC 1 or MHC 2 play the most important role in accepting or rejecting a donor graft?
MHC 2
How long does it take to see a hyperacute graft rejection?
24 hours
how long does it take to see a acute graft rejection?
few days to weeks
how long does it take to see a chronic graft rejection?
months to years
what drug is used in acute rejection of organ transplant?
ATG (anti-thymocyte globulin)
what is Graft vs Host disease?
when immunocompetent grafted lymphocytes attack
cells in an allogeneic recipient whose immune system is compromised
what should be checked for first before a kidney graft is done?
ABO Blood type
what is cross-matching?
placing recipient serum onto donor lymphocytes. A cytotoxic reaction suggests the presence of preformed donor-specific Antibodies
how does the minor histocompatibility affect a graft?
it may cause rejection of the graft
who is the ideal, first choice donor?
identical twin
1 haplotype parent or sibling that will donate a tissue must match at what HLA level?
HLA-DR region
appart from HLA-DR compatibility, what other compatibility must be taken into consideration?
blood type
what does Cyclosporin A and FK506 inhibit?
IL-2 and T cell proliferation
what does rapamycin do?
it interferes with IL-2 —- IL-2R interaction
Cyclosporin A and FK506 are what type of inhibitor?
calcineurin inhibitor
what inhibits cytokines production?
corticosteroids
what is a purine analog inhibiting DNA synthesis in the division of T cells?
Azathioprine
Rapamycin will block what intracellular pathway? and how?
will block mTOR by forming a complex with FK506 binding protein
