Which of the following statements regarding rejection of solid organ transplants is true?

Transplant Rejection Type Onset Mechanism & Vessel Histology Type of Hypersensitivity Hyperacute Immediate Preformed antibodies directed against the donor tissue. Caused by accidental ABO blood type incompatibility which is very rare. Presents while still in surgery with thrombosis and occulsion of graft vessels II Acute Weeks to months T-cell mediated immune response directed against the foreign MHC. Inflammation and leukocyte infiltration of graft vessels results. Most common type IV Chronic Months to years T-cell mediated process resulting from the foreign MHC "looking like" a self MHC carrying an antigen. Results in intimal thickening and fibrosis of graft vessels as well as graft atrophy III & IV Graft vs. Host Varies Donor T-cells in the graft proliferate and attack the recipient's tissue. Most commonly seen in bone marrow transplants. Presents with diarrhea, rash and jaundice IV The most impoant thing to remember is the timerframe for the onset of symptoms as you can often determine hat type of rejection it is based on time alone