Clinicians are often faced with therapeutic dilemmas and challenges while treating children with frequently relapsing
steroid-dependent nephrotic syndrome (SDNS) and
steroid-resistant nephrotic syndrome (SRNS). In the past, children with SDNS have been treated with long-term alternate day
steroids cyclophosphamide,
cyclosporine (CSA),
chlorambucil,
levamisole, and
azathioprine. The essential aim of these
therapies is to maintain remission while limiting exposure to
steroids. These medications have variable efficacy and undesirable toxicity profiles. Recently,
mycophenolate mofetil (MMF) has emerged as a new therapeutic option for the management of SDNS in a few uncontrolled clinical trials. Preliminary data are encouraging. MMF was found to be useful in maintaining remission and has a
steroid-sparing effect. Clearly, more data are needed to further characterize the safety and efficacy of MMF, define adequate length of treatment, and optimize
drug exposure and monitoring. The management of SRNS is primarily aimed at decreasing
proteinuria and inducing remission, if possible. By doing so, one would aim to preserve renal function. CSA
therapy is known to be useful in this regard but has undesirable side effects, the most concerning being nephrotoxicity. MMF in combination with
steroids and
angiotensin-converting enzyme-inhibitor drugs is known to have some efficacy in the management of SRNS. These preliminary data have prompted the National Institutes of Health to sponsor a multicentric controlled trial to compare the safety and efficacy of MMF with that of CSA in the treatment of
steroid-resistant
focal segmental glomerulosclerosis (FSGS). If MMF
therapy is found to be efficacious, it would help obviate the need for CSA and its associated nephrotoxicity. Clearly, MMF has emerged as an important new therapeutic option for the treatment of childhood
nephrotic syndrome and FSGS. Further data are required to assess those conditions most likely to respond.