Tacrolimus Can Induce Remission in Cyclosporine (CsA) and Mycophenolate Mofetil (MMF) Resistant Pediatric Onset Nephrotic Syndrome

Nephrotic syndrome (NS) is a common pediatric renal disorder. Most of these patients are steroid responsive. 10%–20% of children with new onset NS are resistant to steroid therapy. Patients who are resistant to steroids have limited treatment options such as calcineurin inhibitors (CNIs), mycophenolate mofetil (MMF), and rituximab. Despite several studies had documented that tacrolimus is superior to cyclosporine A (CsA) and MMF in treating SRNS but no study was conducted to prove the efficacy of tacrolimus in treating CsA and MMF resistant NS in pediatric populations. The study objective was to evaluate the role of tacrolimus in treating refractory idiopathic nephrotic syndrome. Methods. One hundred and twenty patients with idiopathic nephrotic syndrome were included in the study. Patients with steroid resistant NS were given cyclosporine (CsA) (first step protocol). In patients with cyclosporine resistant NS a combination of CsA+ MMF was given as a second step protocol. Unresponsive patients received tacrolimus as a third step treatment protocol. Tacrolimus was given at a starting dose of 0.1 mg/kg/d then the dose was modified according to serum trough levels and patients were followed up for 12 months to evaluate the outcome. Results. Out of 120 patients, 15 cases were both cyclosporine and MMF resistant and received tacrolimus. Tacrolimus had induced remission in 11 (73.3%) patients during the first 6 months of therapy. Eight patients achieved complete remission and three patients reached partial remission. Conclusions. Tacrolimus is effective in treating refractory multidrug resistant NS with favorable outcomes in childhood onset NS.