Haplotypes II Flashcards
What time frame characterizes acute rejection?
On a time scale of within weeks of transplantation.
What drives acute rejection?
CD4+ T cell mediated.
Define chronic rejection.
Episodic bouts of rejection occurring months to years after transplantation.
What is the mechanism of chronic rejection?
Both cellular and humoral mechanisms are functional. This results in interstitial fibrosis, vascular occlusion, and loss of function.
What time frame characterizes hyperacute rejection?
Rejection occurs within minutes.
When does hyperacute rejection occur?
Occurs when a graft never takes because of pre-existing sensitivity (white graft).
What is the mechanism of hyperacute rejection?
The presence of alloantibodies against the donor’s HLA or ABO antigens at the time of transplantation does not permit the graft to take. These antibodies react with the vascular endothelium of the graft and promote clotting and thrombosis/ necrosis and cause rapid organ death.
What is a graft-vs-host reaction?
When immunocompetent tissues are allografted, they may recognize the recipient (i.e. host) as foreign resulting in CMI damage to the recipient.
When will a graft-vs-host reaction necessarily not be able to occur?
In an immunoincompetent host.
What signs and symptoms characterize a graft-vs-host reaction?
Skin rash, diarrhea, jaundice.
What are the three most common immunosuppressive drugs used to prolong graft acceptance?
Cyclosporine A, Tacrolimus, Mycophenolate mofetil.
What cytokine is suppressed by corticosteroids?
IL-1 and IL-2.
What condition is associated with an HLA-A3 haplotype?
Hemochromatosis (p.194)
What haplotype is hemochromatosis associated with?
HLA-A3 (p.194)
What condition is associated with DQ2/DQ8 haplotypes?
Celiac disease (p.194)
