Background: Cyclosporin A (CyA) can suppress relapses and reduce proteinuria in frequent-relapse nephrotic syndrome (FRNS) and steroid-resistant nephrotic syndrome (SRNS). However, some patients remain resistant to CyA therapy. The purpose of the present paper was to evaluate mycophenolate mofetil (MMF) treatment in pediatric patients with CyA-resistant intractable nephrotic syndrome.
Methods: MMF therapy was given to 11 patients with FRNS who had relapse despite CyA therapy, and one patient with SRNS who had been receiving combined therapy using steroid and CyA until immediately before the start of MMF. MMF was administered at a daily dose of 750–1000 mg/m2 in two divided doses.
Results: Ten of the 11 patients with FRNS were able to maintain remission. Among them, seven patients remained relapse free for 1 year, and two patients had a decrease in the frequency of relapse after initiation of MMF therapy. One patient, however, had repeated cycles of remission and relapse, and was considered resistant to MMF therapy. The total prednisolone dose during the period from month 6 to month 12 after the start of MMF therapy was significantly lower than that during the 6 month period before the start of MMF therapy. The patient with SRNS, who had not achieved remission despite CyA administration, had complete remission on MMF. No serious adverse effects were seen in any of the present patients.
Conclusion: MMF could be useful in CyA-treatment-refractory FRNS and CyA-resistant SRNS.