Transplant and Amyloidosis--Nelson Flashcards
Autograft
Isograft
Allograft
Xenograft
Autograft: patient to self
Isograft: identical twin to patient
Allograft: other to patient
Xenograft: animal to patient
Direct rejection pathway
MHC-I and -II presented by transplanted tissue cells
–> recognized by host immune system
Indirect rejection pathway
recipient APCs present foreign antigen to host immune system
Mechanism of hyperacute rejection
pre-formed anti-ABO or anti-HLA antibodies
–> antibodies bind endothelium
–> complement activated
–> thrombi
Mechanism of acute rejection
T-cell mediated hypersensitivity
Chronic rejection mechanism
combination of B- and T-cell mediated damage
2˚ to vascular injury
How to prevent tissue rejection?
ABO and HLA matching
2 risks assocated with immunosuppression
opportunistic infection
increased malgnancy risk
Autologous hematopoietic stem cell transplantation
protenitor cells taken from patient
Allogeneic hematopoietic stem cell transplantation
progenitor cells from donor
What is the most important test to consider before transplanting tissue?
HLA compatability testing
Graft vs. Tumor reaction
if relapse occurs…
“new” immune system recognizes tumor cells as foreign
*unique benefit of allogenic transplant
Graft vs. Host disease classifications
acute: < 100 days
chronic: > 100 days
What stain do you use for amyloid?
Congo Red
What color does amyloid turn under Congo Red?
apple green
