Kidney biopsy findings in cyclosporine-treated patients with insulin-dependent diabetes mellitus.

Renal biopsy specimens of 40 patients with recent-onset insulin-dependent diabetes mellitus treated with cyclosporine (CSA) for 6-29 months were examined. Cyclosporine-associated chronic vascular interstitial toxicity of moderate intensity was found in 10 patients (25%). The most prominent lesions were interstitial fibrosis and tubular atrophy. Arteriolopathy was less pronounced and glomerular damage unremarkable. A significant correlation exists between the extent of tubular atrophy and CSA trough whole blood levels. These data indicate that the development of CSA-associated chronic nephropathy is dose-dependent.