Five-year outcome of children with idiopathic nephrotic syndrome: the NEPHROVIR population-based cohort study

BackgroundThe optimal therapeutic regimen for children at onset of idiopathic nephrotic syndrome (INS) is still under debate. A better knowledge of the disease's course is necessary to design more appropriate and/or personalized treatment protocols.MethodsWe report the 5-year outcome of patients included from December 2007 to May 2010 in the prospective multicentric and multiethnic population-based NEPHROVIR study. Patients were treated at onset according to the French steroid protocol (3990mg/m(2), 18weeks). Data were collected at 5years or last follow-up.ResultsOut of the 188 children with nephrotic syndrome (121 boys, 67 girls; median age 4.1years), 174 (93%) were steroid-sensitive. Six percent of steroid-sensitive patients required intravenous steroid pulses to get into remission. Relapse-free rate for steroid-sensitive patients was 21% (36/174) at last follow-up (median 72months). A first relapse occurred in138 steroid sensitive patients (79%) with a median time of 8.3months (IQ 3.4-11.3). Out of the 138 relapsers, 43 were frequent relapsers. Age at onset below 4years was the only predictive factor of relapse, while gender, ethnicity, and delay to first remission were not. At 96months of follow-up, 83% of frequent relapsers were still under steroids and/or immunosuppressive drugs.ConclusionsThe treatment of the first flare deserves major improvements in order to reduce the prevalence of relapsers and the subsequent long-lasting exposure to steroids and immunosuppression.