TRANSPLANTS AND REJECTION Flashcards
Which genes determine whether a Transplanted tissue will be rejected or not?
HLA Genes
Destruction of Transplanted tissue is made by
Adaptive Inmune System
3 Types of Transplant
1) Syngenic: Between genetically identical animals
2) Allogenic: Same species, different genetically
3) Xenogenic: Differente species
How APCs start the attack to graft tissue
Recipient APCs ingest foreign MHC molecules from transplanted tissue
Once APCs ingest MHC molecules, they migrate into the ________________ and activate ___________________
Lymph nodes / T-Cells
In transplant rejection, once Activation of T-Cell occur, what do T-Cell do?
Migration to graft location = Release of inflammatory Cytokines
Hyperacute rejection: Time before onset
5-30’ after transplant
Hyperacute rejection: Features
Thrombosis of graft vessels + Isquemic necrosis
Hyperacute rejection: Mechanism
Presence of AB specific for MHC antigens. Due to prior exposure
Acute rejection: Time before onset
Days to weeks after transplant
Acute rejection: Mechanism
Formation of NEW EFFECTOR T Cells and B Cells
Acute rejection: Features
- Can be prevented with Inmunosupressors
- Most common kind of rejection
- Vasculitis + Dense interstitial Lymphocytic infiltrate
Chronic rejection: Time before onset
Past 1-year after transplant
Chronic rejection: Mechanism
Slow activation of T-Cells
PROLIFERATION OF FIBROBLASTS
Chronic rejection: Features
- Cannot be prevented with inmunosupressors
- Most comon kind > 1 year after transplant
- Proliferation of vascular smooth muscle+ arteriosclerosis + fibrosis
