Cyclosporine-associated nephropathy in patients with heart and bone marrow transplants.

The morphology of kidneys from heart (n = 55) and bone marrow (n = 112) transplant recipients treated either with cyclosporine (CSA) or conventional immunosuppression was investigated at autopsy. The major findings were: In the bone marrow transplant recipients glomerular collapse, tubular atrophy, interstitial fibrosis, striped form, CSA-associated arteriolopathy and thrombi in glomeruli and/or arterioles were more often found in the CSA group as compared to conventional immunosuppression. In the heart transplant recipients glomerular collapse and obsolescence, tubular atrophy and intimal fibrosis in arteries were more frequent in the CSA group. Vascular interstitial toxicity known to be associated with CSA treatment from renal transplant patients was found in 54% (25% severe) of the bone marrow and 19.5% (9.7% severe) of the the heart transplant recipients. The prevalence of vascular interstitial toxicity in bone marrow versus heart transplant recipients is possibly due to higher CSA dosage and pretreatment with cytostatic drugs and irradiation. Analyses of the lesions from early stages to the full picture of vascular interstitial toxicity suggests that CSA causes a form of thrombotic microangiopathy with focal glomerular and/or arteriolar thrombosis followed by typical CSA-associated arteriolopathy which results in interstitial fibrosis with tubular atrophy.