Immuno path I - Transplantation Flashcards
Describe direct cellular rejection
The donors APC cells precent HLA antigen to the host TH1 cells causing a type IV hypersensitivity.
Describe indirect cellular rejection
The hosts APC infiltrate the graft and present the donors HLA molecules to the host immune system.
Describe Ab mediated Vasculitis
Caused by humoral rejection in a type II hypersensitvity (Ab mediated).
This leads to opsonization and recruitment of macrophages that destroy the vasculature.
Describe immune complex vasculitis
A type III hypersensitivity (Antigen-antibody complex).
Hosts Ab form complexes with donor Ag. that cause vascular damage.
This causes necrotizing vasculitis!
What is the hallmark of Hyperacute kidney rejection?
Host has previously sensitized Ab due to previous transplant, pregnancy, or transfusion.
Specifically targets vasculature with Ag-Ab complexes.
What is the hallmark of Acute kidney rejection damage?
Caused by CD8 and CD4 cells targeting both the tubules (CD8) and the vasculature (CD4 ab-ag)
What lab results are commonly seen in acute kidney rejection?
Increased BUN levels
Decreased creatinine
Decreased urine output.
What are the clinical manifestations of chronic kidney rejection?
Fibrosis with tissue ischemia, tublar atrophy, and interstitial mononuclear infiltrates.
Pt will present with anuria as well.
What are the hallmarks of acute liver damage?
Rejection occurs within 40% of pt within first 3 months.
Characterized by bile duct damage and endothelitis.
Vanishing bile duct syndrome due to cellular immune damage compounded by ischemia from Ab-mediated damage to hepatic arterioles are all hallmarks of what?
Hallmarks of chronic liver rejection.
What is graft artherosclerosis of the heart?
Change resembling accelerated coronary artery disease.
Diffuse intimal thickening and accumulation of foamy macrophages.
Why do patients experieincing heart graft failure not experience chest pain?
The cardiocytes are often denervated thus Silent MI’s are common!
EBV associated malignancies are commonly associated with what?
Heart transplants due to immunosupression.
Describe graft vs host disease.
The immunocompetent immune cells within the graft attack the immunosupressed cells of the host!
Tends to target skin, GI and liver.
What is the clinical triad of acute Graft vs Host disease?
Dermatitis - Exfoliation or rash
Enteritis = Bloody diarrhea
Hepatitis - Hepatocyte/Bile duct necrosis leading to jaundice.
Overall damage of epithelial cells in these targets
