Immunologic enhancement of rat renal allografts. I. Comparative morphology of acutely rejecting and passively enhanced grafts.

The acute unmodified rejection of (Lewis x Brown Norway) F(1) to Lewis renal allografts is characterized by an early and progressive lymphoid cell infiltrate, glomerular necrosis, necrotizing arteritis and ischemic cortical necrosis leading to graft destruction. A single low dose of enhancing antiserum given at the time of transplantation prolongs graft survival by abrogating the necrotizing lesions in glomeruli and arteries and the subsequent cortical necrosis. Passive enhancement in this model is interpreted as representing predominantly a block in the humoral antibody-mediated rejection response. It is suggested that the block is effected mainly, peripherally, ie, at the level of the transplanted kidney itself.