The nature of experimental second-set kidney transplant rejection. 1. The role of coagulation in hyperacute (second-set) renal allotransplant rejection in dogs.

The role of coagulation in the hyperacute rejection of transplanted kidneys was investigated in 10 sensitized dogs, the tests including routine screening tests for detecting intravascular coagulation as well as measurements with radioactive fibrinogen. Five sensitized and transplanted but not rejecting dogs together with 2 autotransplants and 2 normal animals served as a control. Small to moderate changes occurred in nearly all the parameters studied, although more as a result of the underlying surgical trauma rather than that of the rejection process itself. Rejection could not be prevented by establishing therapeutic hypofibrinogenaemia and its incidence did not increase by introducing blockade of the fibrinolytic system. The presented data provide no evidence to support the hypothesis that the reaction leading to hyperacute rejection of kidney allotransplants is initiated by systemic coagulation.