Comparison between pre- and posttreatment renal biopsies in children receiving ciclosporine for idiopathic nephrosis.

Fourty-two children with idiopathic nephrosis that had not been well controlled by other forms of therapy were treated with ciclosporine. Thirty-three of them were steroid dependent, 2 were partial steroid responders and 7 were steroid resistant. On pretreatment renal biopsy, performed in all patients less than 6 months before starting ciclosporine, minimal change disease (MCD) was diagnosed in 37 children and focal glomerular sclerosis (FGS) in 5. In order to evaluate the morphological changes of the renal parenchyma possibly induced by the drug, posttreatment biopsies were performed in these 42 patients: one in all patients after 4 to 28 months of ciclosporine, 2 in 23 patients after 18 to 42 months of treatment, 3 in 8 patients after 30 to 63 months of treatment and 4 in 2 patients who had been treated respectively for 62 and 63 months. The morphological changes on pre- and posttreatment biopsies were scored according to the severity of tubulointerstitial lesions. Grade I was considered when there were no significant changes of the renal parenchyma or when occasional scattered tubules with thickened basement membranes were present. Grade II was diagnosed when the biopsy showed several small foci of atrophic tubules with thickened basement membranes within stripes of interstitial fibrosis and grade III when confluent or extensive areas of interstitial fibrosis with atrophic and/or collapsed tubules were observed. On pretreatment renal biopsy, only one patient showed tubulointerstitial lesions (grade II). On the latest biopsy obtained, 18 patients showed grade I tubulointerstitial lesions, 15 grade II and 9 grade III. Unspecific arteriolopathy was observed in 10 patients.(ABSTRACT TRUNCATED AT 250 WORDS)