CHILDHOOD NEPHROTIC SYNDROME (2) FRESH-PEF5128-en Georges DESCHNESE CHILDHOOD NEPHROTIC SYNDROME (2) NEPHROVIR 2 FRESH-PEF5128-en 5128 FRESH-PEF5128 NCT01609426 Georges DESCHENES INSTITUT NATIONAL DE LA SANTE ET DE LA RECHERCHE MEDICALE (INSERM) ASSISTANCE PUBLIQUE HOPITAUX DE PARIS (AP-HP) Epidemiology France Portal (PEF) MINISTERE DU TRAVAIL, DE LA SANTE, DES SOLIDARITES ET DES FAMILLES null Analysis immuno-virological status idiopathic corticosteroids B lymphocytes health episodes proteinuria glucocorticoids after-effect immunosuppressants Epstein Barr Virus (EBV) impact progression incidence recurrence complications Paediatrics Nephrology Nephrotic syndrome Behavioral determinants To analyse the immuno-virological status of patients concerning Epstein Barr Virus (EBV) during the first manifestation of idiopathic nephrotic syndrome, and its impact on steroid therapy progression. A further study is proposed for the phenotypic characterisation and analysis of B lymphocytes in patients with relation to the EBV cycle. null France Ile-de-France Individuals Patients population Male Female Infant, Newborn (birth to 28 days) Infant (28 days to 2 years) Child, Preschool (2 to 5 years) Child (6 to 12 years) Children between 6 months and 15 years old, living in the Ile de France area, with first manifestation of idiopathic nephrotic syndrome defined as proteinuria higher than 50 mg/kg/day or proteinuria/creatinine higher than 0.25 g/mmol and hypoalbuminemia less than 30 g/L. Group 2: negative serology for hepatitis B and hepatitis C virus, no decrease in C3 component. Group 3: samples for hepatitis B virus, hepatitis C virus and C3 complement component serology. Children not living in Ile de France at time of first manifestation are excluded. Clinical data Health event/morbidity Health event/mortality Health care consumption and services Other Through organizations (health services or institutions schools businesses etc.) < 500 individuals Self-administered questionnaire Interview with the participant (including clinical) Observational Study Observational Study Cohort study 350 Unknown Restricted access Data may be used by industrial teams. Data may not be used by industrial teams. Contractual access. Access on specific project only