immuno 23.txt

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immuno 23.txt
2011-04-28 19:42:33

immuno 23
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  1. Allograft
    same species, different genes
  2. Isograft
    Identical twin
  3. Autograft
  4. Xenograft
    different species
  5. What is the strongest immune response alloantigen?
    MHC molecules
  6. What are alloreactive antibodies?
    Lymphocytes and Abs that react to alloantigens from transplants
  7. Which are the 6 most important alleles to match for a successful transplant?
    • HLA-A
    • HLA-B
    • HLA-DR
  8. How many haplotypes does each individual have?
    20 (e.g. A-B + C-D)
  9. What is indirect presentation?
    Recipient MHC molecules present peptides from graft to T-cells
  10. What is direct presentation?
    Donor MHC molecules present as self to T-cell
  11. What cells attack chronic grafts?
    T helper cells
  12. What cells attack acute grafts?
  13. Is graft rejection, CMI or Humoral mediated?
    Both CMI and humoral
  14. what is a hyperacute transplant rejection?
    • Predisposed antibodies attach alloantigen on graft
    • Alloreactive antibodies caused by previous exposure via grafts, transfusion, etc...
  15. How fast does a HaTR occur?
  16. What two tests are performed to avoid hyperacute transplant rejection?
    • ABO typing
    • crossmatching tests
  17. How fast does an acute transplant rejection occur?
    7-10 days
  18. What is the active cell in hyperactive and acute rejection?
    • Hyperactive: PMN and platelets
    • Actute: Tcells (Th and CTL)
  19. How fast does chronic rejection occur?
    Months to years
  20. What is the active cell in chronic rejection?
    • fibroblasts, GF, and cytokines
    • ** irreversible as they lay down scar tissue
  21. What happens to survival rate as HLA mismatch increases (HLA-A, HLA-B, HLA-DR for 6 total)?
    • Survival decreases
    • ** heart and liver can survive less matches with immunotherapy
  22. What are the two steps in successful chronic rejection?
    • Smooth muscle proliferation
    • Inflammation