title: Second-line immunosuppressive treatment of childhood nephrotic syndrome: a single-center experience.
abstract: OBJECTIVE
  Most cases of idiopathic nephrotic syndrome in childhood are responsive to corticosteroids. However, there is a small group of children that demonstrate steroid resistance (steroid-resistant nephrotic syndrome; SRNS), steroid dependence, or that frequently relapse (frequent-relapse steroid-sensitive nephrotic syndrome; FR-SSNS) which are more clinically difficult to treat. Therefore, second-line immunosuppressants, such as alkylating agents, calcineurin inhibitors, antimetabolites and, more recently, rituximab, have been used with varying success. The objective was to evaluate the response rates of various second-line therapies in the treatment of childhood nephrotic syndrome.
  
  
  METHODS
  A retrospective chart review of pediatric subjects with idiopathic nephrotic syndrome was conducted at a single tertiary care center (2007-2012). Drug responses were classified as complete response, partial response, and no response.
  
  
  RESULTS
  Of the 188 charts reviewed, 121 children were classified as SSNS and 67 children as SRNS; 58% were classified as FR-SSNS. Sixty-five subjects were diagnosed with focal segmental glomerulosclerosis via biopsy. Follow-up ranged from 6 months to 21 years. The combined rate of complete and partial response for mycophenolate mofetil (MMF) was 65% (33/51) in SSNS and 67% (6/9) in SRNS. For tacrolimus, the response rate was 96% (22/23) for SSNS and 77% (17/22) for SRNS. Eighty-three percent (5/6) of SSNS subjects treated with rituximab went into complete remission; 60% relapsed after B-cell repletion. Eight refractory subjects were treated with combined MMF/tacrolimus/corticosteroid therapy with a 75% response rate.
  
  
  CONCLUSIONS
  Our experience demonstrates that older medications can be replaced with newer ones such as MMF, tacrolimus, and rituximab with good outcomes and better side effect profiles. The treatment of refractory cases with combination therapy is promising.
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: N
authors.initials: N
authors.lastname: Patnaik
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: N
authors.initials: N
authors.lastname: Chorny
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: R
authors.initials: R
authors.lastname: Frank
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: L
authors.initials: L
authors.lastname: Infante
authors.affiliation: Division of Pediatric Nephrology, Department of Pediatrics, Cohen Children's Medical Center of New York, North Shore-LIJ Health System, New Hyde Park, N.Y., USA.
authors.forename: C
authors.initials: C
authors.lastname: Sethna
keywords: Childhood nephrotic syndrome; Frequent-relapse steroid-sensitive nephrotic syndrome; Rituximab; Second-line immunosuppressive treatment; Steroid-dependent nephrotic syndrome; Steroid-resistant nephrotic syndrome; Tacrolimus