[Renal lesions induced by cyclosporin. Apropos of 4 renal biopsies and 22 necropsies of recipients of heart transplant].

The morphological study of kidney in patients without any preexistent renal disease and treated by cyclosporine corroborated the nephrotoxicity of this immunosuppressive drug. 4 biopsies (in 2 patients with Behçet's disease, in 1 recipient of allogenic medullary graft and 1 recipient of heart transplant) were performed for acute renal failure observed in a variable time after the beginning of treatment (7th day to 14 months). In two cases, they demonstrated obvious vascular lesions (arteriolar or glomerular thrombosis, fibrinoïd necrosis) and they detected constantly changes of proximal convoluted tubules (epithelial vacuolization or necrosis, calcifications). In addition, the ultrastructural study performed in all cases showed a striking increase of lysosomes and some giant mitochondria. The 8 autopsies of recipients with heart transplants treated by cyclosporine for more than 1 month corroborated also these renal changes which were always correlated with biological perturbations of the renal function (increase of level of serum creatinine). Besides the proximal convoluted tubular lesions (vacuolization, necrosis and calcifications), an obvious increase of the interstitial tissue proportional to the long time of treatment was always detected.