Essay on Rejection Of Blood Flow Into The Graft

701 Words Sep 17th, 2015 3 Pages
1.3.1 Hyperacute rejection
Hyperacute rejection occurs immediately after transplantation, typically within minutes to hours. It is due to the presence of preformed antibodies in the recipient’s serum which are either directed against donor HLA antigens (referred to as DSAs) or ABO blood group antigens located on the graft endothelium {Chan:2000ui, Howell:2010fg, Overviewoftranspla:2013ty, ImmunologicAspects:2002tn}. Following anastomosis and blood flow into the graft, the antibodies bind to their respective antigens on the vascular endothelium activating the complement cascade and also the clotting cascade. This leads to the accumulation of granulocytes and platelets in the graft, and ultimately the formation of thrombi. The thrombi block the vessels of the graft resulting in ischaemia and infarction {Chan:2000ui, Howell:2010fg, Overviewoftranspla:2013ty, ImmunologicAspects:2002tn}. Interestingly, not all solid organ transplants are susceptible to hyperacute rejection. The liver is relatively resistant to hyperacute rejection, whereas kidneys and heart are more susceptible. The exact mechanism behind this phenomenon is not fully understood, but it is speculated that the large cell mass of the liver is capable of absorbing circulating antibody {Chan:2000ui, Howell:2010fg, Overviewoftranspla:2013ty, ImmunologicAspects:2002tn, McKenna:2000tr}.
1.3.2 Accelerated rejection
Accelerated rejection occurs within days, typically three to five, of the transplant taking place. The graft…

Related Documents