Acute tubulointerstitial nephritis following aciclovir treatment for chickenpox in children with nephrotic syndrome - a report of two cases.

Tubulointerstitial nephritis (TIN) is an inflammatory process primarily involving the renal interstitium and is the cause of acute kidney injury (AKI) in 3-7% of cases confirmed by renal biopsy in children. Aciclovir may have a nephrotoxic effect by crystallization in renal tubules or by inducing an immunologic process that leads to development of TIN. We report 2 male patients, aged 10 and 8 years, with nephrotic syndrome (NS), in whom disease relapse was triggered by varicella zoster infection. The patients received intravenous aciclovir which resulted in AKI due to acute TIN with the glomerular filtration rate 19.5 and 24.9 ml/min/1.73 m2, respectively. The diagnosis was confirmed by kidney biopsy in one of these patients. Initiation of glucocorticosteroids and withdrawal of aciclovir resulted in resolution of proteinuria and symptoms of AKI. In children with active NS treated with intravenous aciclovir, a possibility of AKI due to TIN should be taken into account.