Transplants Flashcards
(22 cards)
Autograft
tissue transferred from one body site to another on same individual
Isograft
tissue transferred between genetically identical individuals
Allograft
tissue transferred between genetically different individuals
Xenograft
tissue transferred between different species
Host vs Graft Disease
tissue is rejected by host
Graft vs Host Disease
host attacked by transplanted T cells
Play central role in rejection
T cells- CD4 and CD8
CD4 more important
Graft Rejection
cell mediated immune response- Type 2 and 4
Sensitization Stage of Graft Rejection
CD4 and CD8 recognize alloantigens and activate T lymphocytes
Effector Stage of Graft Rejection
immune destruction of graft
Cytokines released by Th cells play central role
TNF-B (LT-a) cytotoxic to graft cells
Recognize MHC1
CD8
Recognize MHC2
CD4
Hyper Acute Rejection
Antibody Mediated
0-3 days
due to pre existing host antibodies to HLA
Acute Rejection
T Cell Mediated
3 days- 6 months
mononuclear cells infiltrate graft
Chronic Rejection
Antibody and Cell Mediated
>6 months
Microcytotoxicity Test
test for HLA
by adding Ab against MHC 1 and 2 Ag
dead cells take up dye- presence of MHC Ag
Which is more important, MHC 1 or 2?
MHC 2
MHC 1 associated with
HLA-A and HLA-B
MHC 2 associated with
HLA- DR
Mixed Lymph Response
determine compatibility by mixing killed donor lymphocytes with recipient lymphocytes
Immunosuppression Therapy
causes general immunosuppression to all Ag
inhibits proliferation of activated lymphocytes
Transplant Complications
Infection
Malignancy
Tissue Rejection
