Chapter 13 ( Transplantation )

Question 1

Hyperacute graft rejection timing ? Mechanism ?

Answer 1

Within minuets to hours

Due to preformed antibodies due to transfusion , multi-parity or previous organ transplants ( type ll cytotoxic hypersensitivity ) , antibodies bind to the grafted tissue and activate complement and the clotting cascade resulting in thrombosis and ischemic necrosis

Question 2

Acute graft rejection timing and mechanism ?

Answer 2

Within days to weeks

Similar to primary immune response
Induced by alloantigens in the graft , both CD4,8 T cells play a role as well as antibodies

Question 3

Daclizumab , Basiliximab mechanism of action ?

Answer 3

Blocks T cell proliferation by blocking the binding of IL-2 and by opsonization of IL-2R bearing cells

Question 4

Muromonab mechanism of action ?

Answer 4

Blocks T cell activation by causing apoptosis

Question 5

Belatacept mechanism of action ?

Answer 5

Inhibits T cell activation by blocking the B7 costimulatory molecule binding to CD28

Question 6

Alemtuzumab mechanism of action ?

Answer 6

Depletes pool of T cells by binding to them and causing complement mediated lysis