Nephrotic syndrome and mizoribine in children

BACKGROUND: The treatment of nephrotic syndrome (NS) has recently made dramatic progress. The ultimate purpose of treatment is that patients can lead a normal, disease-free life with no adverse effects from treatment. However, clear treatment guidelines remain to be established in the children with frequent relapsing NS (FRNS) and steroid-resistant NS (SRNS). The frequent use or large dose of steroids may lead to a serious adverse effect. Immunosuppressive drugs including cyclophosphamide and cyclosporin have been used to induce lasting remission, thereby sparing patients from further exposure to steroids. However, these drugs have both acute and chronic side-effects. Mizoribine is a relatively safe and effective immunosuppressant. The report discusses the role of mizoribine in FRNS and SRNS in children. METHODS: The papers in experimental and clinical studies about mizoribine in NS were reviewed. Our experiences of mizoribine were also added. RESULTS: Mizoribine has been reported as an effective and safe drug for patients with FRNS. However, the efficacy of mizoribine has differed among various reports, depending on the dose given. There have yet to be any conclusive reports on the effects of mizoribine in SRNS in children. CONCLUSIONS: Better results might be obtained if the doses of mizoribine increased in children with FRNS. When 5 mg/kg was used, no serious adverse effects were seen, therefore this dose may be safe and effective. An investigation of appropriate, effective and safe doses of mizoribine should be examined in the future. In patients with SRNS, large doses of mizoribine of more than 5 mg/kg might be effective, while the combined use of mizoribine and cyclosporin or methylprednisolone pulse therapy might also be even more effective. Further studies are called for to examine the use of large doses of mizoribine.