Infrequent tacrolimus-induced nephrotoxicity in French patients with steroid-dependent nephrotic syndrome.

Abstract

Chronic nephrotoxicity with potentially irreversible lesions is a major concern regarding calcineurin inhibitor (CNI) treatment in children with severe forms of idiopathic nephrotic syndrome (INS). We retrospectively included all children on CNI for steroid-dependent INS with a duration of CNI treatment of more than 1year. Only patients in whom CNI could not be replaced by mycophenolate mofetil were included. All included patients underwent a kidney biopsy. All results were expressed as median and range. Twenty-one children (6 girls) were included. Age at disease onset was 49 (29-66) months and treatment duration on CNI was 30 (20-45) months. Age at kidney biopsy was 108 (78-170) months. Number of relapses was 7 (3-9) since disease onset. Serum creatinine level was transiently and moderately increased in two patients. Kidney biopsy revealed minimal change disease in 20/21 patients and focal segmental glomerulosclerosis in 1/21. Evidence for chronic CNI nephrotoxicity was found in one patient revealed by arteriolar hyalinosis and fibrosis in 50% of glomeruli. CNI-induced chronic nephrotoxicity was infrequent. In patients who require long-term and/or high-dose CNI treatment, kidney biopsies might be useful to exclude chronic CNI-induced lesions.