Outcome of Childhood Onset First Episode of Nephrotic Syndrome

Background: Most patients with idiopathic nephrotic syndrome (NS) are steroid-responsive, about 50% relapse and often become steroid-dependent. The aim of this study was to determine epidemiology, treatment and outcome of children with first episode of NS. Methods: This was a retrospective hospital-based cohort study in the department of pediatric nephrology of Charles Nicolle, Tunis, between 2002 and 2012. It included 52 children with idiopathic NS aged from 1 to 12 years, hospitalized for the first manifestation of the NS and followed for at least one year. Results: The median age of presentation was 5.1±2.5 years. Male to female ratio was 2.7:1. Family history of atopy was found in 14 (26.9%) patients and personal atopy was noted in 9 (17.3%) patients. Microscopic hematuria was seen in 33 (63.5%) patients. The mean blood level of albumin was 1.17±4.2 g/dl, alpha-2 globulin was 1.71±3.5g/dl, cholesterol was 413.7±2.4 mg/dl and the mean proteinuria was 148±70 mg/kg/day. The mean time for first remission was 15.8±2 days. Thirty-eight patients (73%) relapsed and 31 patients (59.6%) became steroid dependent. Total 32 (61.5%) patients recovered from their NS with average interval between the onset of illness and recovery being 3.8±2.1 years (range: 2-10 years). Twenty-two (42.3%) required immunosuppressive drugs such as cyclophosphamide, mycophenolate mofetil and cyclosporine. Thirty-two patients (61.5%) were in remission and off therapy for more than 2 years. The most frequents adverse effects of steroid treatment were growth failure in 22 (42.3%) and osteoporosis in 7 (21.8%) patients. Renal functions remained normal for all patients. Conclusion: The prognosis of idiopathic NS is good but the risk of progression to steroid dependence is high, which exposes these children to complications of long-term corticosteroid therapy. Prospective trials are necessary to identify effective and safe therapies for patients with frequent relapses and steroid dependence.