Fetal Transplant Flashcards
What is the main barrier to transplant?
MHC compatibility
What is an autograft?
Self to self
What is an isograft?
Self to identical twin
What is an allograft?
Person to person
What is a xenograft?
Interspecies
How do lymphocytotoxic Ab function?
Incubate recipient serum with lymphocytes of known HLA.
If there are HLA antibodies in the serum they will bind to their MHC antigen on the lymphocyte cell surface.
Complement is then added to all the wells. Lymphocytes that have bound antibody on their MHC will be lysed.
Since the MHC is known for each lymphocyte well, the exact anti-MHC specificity can be determined.
What is the mixed lymphocyte reaction?
Mixing MHC T cells from the recipient with the MHC non-T cells of the donor as APCs (that have been paralyzed) and measure the T cell proliferation and detection of CD8 cells to determine the immune response.
What is direct Ag presentation?
Activation of the immune system occurs through the foreign MHC occurs without MHC processing or Ag presentation via the “passenger leukocytes”
Why is direct Ag presentation a HERESY?
There is not MHC Ag presentation
What is indirect Ag presentation?
It is the classic presentation method with the allo-Ag uptaken and presented on Class II MHC by APCs to CD4 cells
What is hyper acute rejection and why does it occur?
It is accelerated rejection that will occur due to the presence of the allo-Ab complex within 48 hours. This occurs due to the prior presence of Ab as in pregnancy sensitization or difference in blood types.
What is acute rejection?
Anti-donor cells that are formed within 3 weeks due to TMMI reaction via CD4 with B cell Th2 and Th17 response following after
What is chronic rejection?
Slow graft attrition with arteriolar narrowing which causes intimate thickening and graft ischemia
What are the difficulties of bone marrow transplant?
Causes a graft VS host disease that occurs with the marrow forming Ab against the host as the host is in an immunocompromised state
What is the main gene that is a problem fro xenotransplantation?
Inactivation of alpha-1,3-Gal gene that is absent in higher primates