A kidney is transplanted into a patient with renal failure to diabetes,and within 15 minutes after the recipient blood supply to the graft is established,the graft becomes pale,and stops functioning.Microscopic analysis of the failed graft shows death of cells due to lack of blood flow ("ischemic necrosis").What is the most likely cause of this graft failure?
A)Acute rejection due to stimulation of the recipients B and T cells specific for graft alloantigens
B)Chronic rejection,with narrowing of the graft blood vessels by vascular smooth muscle cells and fibrous tissue
C)A leaky surgical connection between the recipient and graft blood vessels
D)Hyperacute rejection,with thrombosis (clotting)of graft blood vessels due to previously formed antibodies in the recipient specific for recipient HLA molecules
E)Damage to the graft by because of the patient's diabetes

Question

Quizplus · Accepted Answer

The rapid development of ischemic necrosis in the graft is diagnostic of hyperacute rejection,which is always caused by antibodies against graft endothelial antigens already circulating in the recipient before the transplantation.The preexisting antibodies may be natural anti-blood group antigens,if the donor and recipient are of incompatible blood types,or anti-HLA antibodies if the recipient has had previous pregnancies or received transfusions transplants in the past.Acute rejection requires the recipient T and B cells to be activated,over the course of several days.Chronic rejection takes months to develop.Damage to kidneys due to diabetes takes years to develop.

A Kidney Is Transplanted into a Patient with Renal Failure