Grafts and Transplant Rejections Flashcards
Autograft
From self
Syngeneic graft
From identical twin or clone
Allograft
From nonidentical individual of the same species
Xenograft
From different species
Onset of Hyperacute Rejection
Within minutes
Onset of Acute Rejection
Weeks later
Onset of Chronic Rejection
Months to years
Onset of Graft-vs-Host Rejection
Varies
Pathogenesis of Hyperacute Rejection
Ab mediated (type II) because of the presence of preformed anti-donor Ab in the transplant patient
Pathogenesis of Acute Rejection
Cell-mediated due to CTLs reacting against foreign MHCs
Pathogenesis of Chronic Rejection
Class I-MHC (non-self) is perceived by CTLs as a class I-MHC (self) presenting a non-self antigen
Pathogenesis of Graft-vs-Host Rejection
Grafted immunocompetent T cells proliferate in the irradiated immunocompromised disease host and reject cells with “foreign” proteins –> severe organ dysfunction
What is given to reverse Acute Rejection?
Immunosuppressants: cyclosporine, muromonab-CD3
Features of Hyperacute Rejection
Occludes graft vessels –> ischemia and necrosis
Features of Acute Rejection
Vasculitis of graft vessels with dense interstitial lymphocytic infiltrate
