title: Response to cyclosporine in steroid-resistant nephrotic syndrome: discontinuation is possible.
abstract: BACKGROUND
  Steroid-resistant nephrotic syndrome (SRNS) is still regarded as a serious disease although treatment with cyclosporine (CSA) has improved outcome. However, the duration of treatment in responders is unclear, and treatment of patients with genetic causes is a matter of debate.
  
  
  METHODS
  Thirty-six patients with SRNS were studied retrospectively. Median age at presentation was 3.2 (range, 0.06-15.0) and median follow-up 15.5 years (range, 1.8-27.7), respectively; 23 (64%) had focal segmental glomerulosclerosis (FSGS) on biopsy. In 33/36 patients (92%), genetic testing was performed for at least three most common genes known to be mutated in SRNS.
  
  
  RESULTS
  Nineteen patients (53%), especially those with minimal change nephrotic syndrome (MCNS) at initial biopsy (p < 0.002), entered complete remission with CSA monotherapy, including one patient with compound heterozygous NPHS1 and dominant ACTN4 mutation, respectively. Ten patients entered partial remission (28%, all FSGS), including two with NPHS2 mutations. Seven patients (six FSGS, one MCNS) did not respond to treatment. In 15 of 19 responders to CSA, treatment was stopped after a median of 3.1 years (range, 0.5-14) and no further relapses occurred in 11/15 (73%) patients with median follow-up of 9.7 years.
  
  
  CONCLUSIONS
  CSA monotherapy is effective in SRNS. Discontinuation of CSA is possible in many patients with complete remission.
authors.affiliation: Pediatric Nephrology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Ilka
authors.initials: I
authors.lastname: Klaassen
authors.forename: Bünyamin
authors.initials: B
authors.lastname: Özgören
authors.forename: Carolin E
authors.initials: CE
authors.lastname: Sadowski
authors.forename: Kristina
authors.initials: K
authors.lastname: Möller
authors.forename: Michael
authors.initials: M
authors.lastname: van Husen
authors.forename: Anja
authors.initials: A
authors.lastname: Lehnhardt
authors.forename: Kirsten
authors.initials: K
authors.lastname: Timmermann
authors.forename: Folke
authors.initials: F
authors.lastname: Freudenberg
authors.forename: Udo
authors.initials: U
authors.lastname: Helmchen
authors.forename: Jun
authors.initials: J
authors.lastname: Oh
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Kemper
mesh_terms: D000185:Actinin / Q000235:genetics*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016572:Cyclosporine / Q000627:therapeutic use*; D005260:Female; D005858:Germany; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D007668:Kidney / Q000473:pathology*; D008297:Male; D054539:Medication Therapy Management / Q000706:statistics & numerical data; D008565:Membrane Proteins / Q000235:genetics*; D009402:Nephrosis, Lipoid / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics; D010597:Pharmacogenetics; D012074:Remission Induction; D012189:Retrospective Studies; D055502:Secondary Prevention
chemical_list: C111453:ACTN4 protein, human; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein; C113267:nephrin; D000185:Actinin; D016572:Cyclosporine