Steroid-resistant idiopathic nephrotic syndrome in children: long-term follow-up and risk factors for end-stage renal disease

Abstract

Steroid resistant idiopathic nephrotic syndrome (SRINS) in children is one of the leading causes of progression to chronic kidney disease stage V (CKD V)/end stage renal disease (ESRD). The aim of this retrospective study is to evaluate the efficacy of immunosuppressive drugs (IS) and to identify risk factors for progression to ESRD in this population. Clinical and biochemical variables at presentation, early or late steroid resistance, histological pattern and response to cyclosporine A (CsA) and cyclophosfamide (CP) were reviewed in 136 children with SRINS. The analyzed outcome was the progression to ESRD. Univariate as well as multivariate Cox-regression analysis were performed. Median age at onset was 5.54 years (0.67-17.22) and median follow up time was 6.1 years (0.25-30.83). Early steroid-resistance was observed in 114 patients and late resistance in 22. Resistance to CP and CsA was 62.9% and 35% respectively. At last follow-up 57 patients reached ESRD. The renal survival rate was 71.5%, 58.4%, 55.3%, 35.6% and 28.5% at 5, 10, 15, 20 and 25 years respectively. Univariate analysis demonstrated that older age at onset, early steroid-resistance, hematuria, hypertension, focal segmental glomerulosclerosis (FSGS), and resistance to IS were risk factors for ESRD. The Cox proportional-hazards regression identified CsAresistance and FSGS as the only predictors for ESRD. Our findings showed that CsA-resistance and FSGS were risk factors for ESRD.