Kidney Transplant Part 1 Flashcards
(164 cards)
The allograft expresses class I and Class II MHC molecules that differ from the recipient’s MHC molecules and can directly stimulate recipient T cells
direct allorecognition
donor antigens can be processed and peptide fragments presented by the host MHC molecules on self-APCs, indirectly stimulating recipient T cells
Indirect allorecognition
Ultimate goal of immunosuppression
Induce specific tolerance to the graft
State of unresponsiveness to specific antigens derived from either self or non-self proteins
immune tolerance
plays central role in presenting foreign antigenic peptide molecules to T cells in a way that they can be recognized by the antigen-specific T cell receptors (TCRs)
MHC/HLA
provides the strongest Mixed Lymphocyte Reaction (MLR) stimulues
HLA-DR
target for anti-HLA antibodies involved in antibody mediated rejection
HLA-DQ
recognized only by primed or previously immunized cells
HLA-DP
HLA-A, B, C
Class I HLA
HLA D
Class II HLA
antibodies react with both B and T lymphocytes
Anti-Class I
react with B, but not T , lymphocytes
Anti-Class II
most important in the first 6 months after transplant
HLA-DR matching
effect is during the first 2 years
HLA-B
does not have effect before 3 years
HLA-A
primary and central event that initiates allograft rejection.
T cell recognition of alloantigens on the APCs
recognize processed antigen on MHC class I molecules
CD8 Cytotoxic T cells
on MHC Class II molecules
CD4 Helper T cells
important regulators of rejection, targets of immuntherapy
adhesion molecules
best-characterized costimulatory molecule, expressed on the surface of essentially all CD4+ and 50% of CD8+ peripheral T lymphocytes
CD28
proteins that function for growth, activation and diffferentiation
Cytokines
chemoattractants of inflammatory cells to a site of immune response
chemokines
alloimmune response against the graft, cellular or humoral
Acute rejection
normally in the first 3 months, but can occur anytime
Acute Cellular Rejection