Study of Adrenocorticotropic Hormone on Children With Frequent Relapse or Steroid-dependent Nephrotic Syndrome: a Prospective, Multicenter, Randomized，Open-label Clinical Trial.

Inclusion Criteria: Age 2-14 years old; Sensitive but frequent relapses or steroids dependence nephrotic syndrome No severe hormonal side effects and/or low-dose steroids dependent idiopathic nephrotic syndrome in children (defined as two relapses with an average dose < 0.5mg/kg/day or equivalent alternate-day dose) Normal renal function: eGFR≥90ml/min/1.73m2; Morning urine protein <1+ or urine protein-creatinine ratio <0.2g/g (<20 mg/mmol) for 3 consecutive days and above when in enroll; Prednisone dose was 1.5-2 mg/kg per day before admission; No use of other immunosuppressants (such as tacrolimus, mortecophenolate, cyclosporin A, cyclophosphamide, levamisole, imidazole ribin, or tripterygium, etc.) within 3 months, and no use of rituximab or beliumab within 6 months. Exclusion Criteria: Family history of nephrotic syndrome, chronic glomerulonephritis, uremia and other kidney diseases; Patients with congenital or acquired immunodeficiency, or with active tuberculosis, active CMV, EBV, hepatitis B, hepatitis C, HIV infection, deep fungal infection, or other active infections; Recurrent or persistent hypertension; Secondary nephrotic syndrome, such as nephrotic syndrome secondary to systemic lupus erythematosus, diabetes, drug poisoning and infection; Combined with other kidney diseases, such as polycystic kidney, ANCA vasculitis, urinary system malformations, etc.; Patients with hypertension, diabetes, tuberculosis, suppurative or fungal infection, gastric and duodenal ulcer disease and heart failure; Patients with other serious heart, liver and other important organs, blood system, endocrine system and other system lesions; Co-occurrence of other monogenic genetic diseases known to affect the condition of nephrotic syndrome; Patients with serious autoimmune diseases or tumors; Use of other immunosuppressants (such as tacrolimus, mortecophenolate, cyclosporin A, cyclophosphamide, levamisole, imidazole ribin, or tripterygium, etc.) within 3 months, and no use of rituximab or beliumab within 6 months; Patients who are known to be allergic to ACTH, glucocorticoids, or any of the components of these drugs, and patients with severe hormone-related side effects History of organ transplantation (excluding corneal and hair transplantation); Patients who had participated in other clinical trials within three months prior to enrollment; Any patient whom the investigator determines is not suitable for inclusion in the trial.