A multicenter randomized controlled trial cyclosporine treatment for frequently relapsing nephrotic syndrome in childhood

INTERVENTION: Cyclosporine C0 monitoring with 80‐100ng/mL for first 6 months and with 60‐80ng/mL for the following 18 months. Cyclosporine C0 monitoring with 80‐100ng/mL for first 6 months and Cyclosporine administration of 2.5mg/kg per day for the following 18 months. CONDITION: Frequently relapsing nephrotic syndrome in children PRIMARY OUTCOME: relapse‐free survival INCLUSION CRITERIA: 1.Primary nephrotic syndrome. 2.Frequently relapsing, based on the International study of kidney disease in children. 3.Biopsy diagnoses of MCNS, where a renal biopsy has been performed before eligibility. 4.Aged under 18 years. 5.Written informed consent from the patients' parents or legal guardians.