An Estimation of Steroid Responsiveness of Idiopathic Nephrotic Syndrome in Iranian Children

OBJECTIVE: Idiopathic Nephrotic syndrome (INS) is the most common form of nephrotic syndrome (NS) in children with the potential of progression to end stage renal disease (ESRD). INS is steroid-responsive in most children, but not all patients respond to it. The aim of this study was to determine the rate of steroid responsiveness in children with INS that referred to Children's Medical Center since 1995 to 2007. METHODS: In as a cross sectional study, the medical records of all children with INS aged 1 to 15 years who were referred to our referral hospital was reviewed. All patients with onset of disease less than 1 year of age, spontaneous remission, secondary forms of NS associated with systemic diseases, and follow up duration of less than 12 months were excluded from the study. Patients were categorized into 6 groups: Group 1 needed biopsy prior to any treatment, group 2 non-relapsing NS, group 3 infrequently relapsing NS, Group 4 frequently relapsing NS, group 5 steroid dependent NS and group 6 steroid resistant NS. FINDINGS: A total of 238 patients were enrolled in the study. Kidney biopsy was performed in 79 cases. Minimal change lesion (MCL) was the most common (36.7%) pathological diagnosis. Steroid responsiveness was found in 81.5% of all cases including: 96% of MCL (consisting of biopsy proven cases and presumed ones), 32% of focal and segmental glomerulosclerosis, 73% of diffuse mesangial proliferation and 58% of membranoproliferative glomerulonephritis patients. During minimal follow up period of 12 months, there were 194 patients in remission, 32 patients with active NS, and 12 patients in ESRD. CONCLUSION: Our study results showed that 81.5% of all patients, 96.2% of MCL and 32% of FSGS patients initially responded to steroid therapy.