Transplant rejection types and graft-versus-host disease morphology, one finding per card.
35 cards · basic cards · AI-written, checked twice. Edit anything.
- What is the timing of hyperacute transplant rejection after revascularization?
- Minutes to hours
- What causes hyperacute rejection?
- Preformed antidonor antibodies already present in the recipient
- What type of hypersensitivity reaction is hyperacute rejection?
- Type II hypersensitivity
- What happens when preformed antibodies bind donor endothelium in hyperacute rejection?
- Complement activation, causing endothelial damage
- What is the characteristic finding in hyperacute rejection?
- Widespread thrombosis of graft vessels
- Why does a hyperacutely rejected graft need to be removed?
- It never becomes vascularized and undergoes ischemic necrosis
- What pretransplant test prevents hyperacute rejection?
- Crossmatch testing for preformed antidonor antibodies
- What is the typical timing of acute transplant rejection?
- Weeks to months after transplant
- What are the two mechanisms of acute transplant rejection?
- Cellular (T cell-mediated) and humoral (antibody-mediated)
- Which immune cells mediate acute cellular rejection?
- CD8+ cytotoxic T cells
- What do CD8+ T cells target in acute cellular rejection?
- Donor MHC antigens on graft cells
- What histologic finding characterizes acute cellular rejection?
- Dense interstitial lymphocytic infiltrate
- What is tubulitis, seen in acute cellular rejection of a kidney transplant?
- Lymphocytes invading and damaging the renal tubular epithelium
- What vascular finding is seen in acute cellular rejection?
- Endothelialitis, lymphocytes beneath the vascular endothelium
- What mediates acute humoral (antibody-mediated) rejection?
- Antidonor antibodies plus complement activation against graft vasculature