Renal transplantation in rabbits. 3. Morphological alterations in allografts.

Abstract

The quantitative morphological alterations in kidney allografts, removed 1 to 14 days after transplantation, have been studied in 118 rabbits. Infiltration by small lymphocytes gradually increased from the first day after transplantation. These cells were later transformed into or followed by larger lymphocytes which dominated the infiltrates after the fourth or fifth day. Swelling or proliferation of endothelial and mesangial cells in the glomeruli slowly became more marked in frequency and extent, followed by proliferations of vascular endothelium and exudation of polymorphonuclear cells and fibrin in glomeruli and vessels. As a rule, proliferative changes were more widespread than exudative changes in the glomeruli and vessels. Thrombosis and cortical necrosis were frequent. In only two cases, however, was massive glomerular microthrombosis present. In the rabbit, the renal allograft reaction differs from renal autograft reaction less in qualitative respects than in quantitative, i.e. by the severity and early appearance of lesions in the allograft.