title: Risk factors for cyclosporine-induced tubulointerstitial lesions in children with minimal change nephrotic syndrome.
abstract: BACKGROUND
  Cyclosporine (CsA) is effective for the treatment of children with steroid-dependent and -resistant nephrotic syndrome (NS), but it can result in chronic CsA nephrotoxicity including CsA-induced tubulointerstitial lesions. The factors responsible for the development of CsA-induced tubulointerstitial lesions are unknown.
  
  
  METHODS
  To identify the risk factors for the development of CsA-induced tubulointerstitial lesions in children with minimal change NS who had been treated with long-term moderate-dose CsA, we compared several clinical and laboratory factors of 37 patients with and without CsA-induced tubulointerstitial lesions by the Mann-Whitney U test, Fisher's exact test, and stepwise logistic-regression analysis.
  
  
  RESULTS
  Thirteen patients had CsA-induced tubulointerstitial lesions and 24 patients had none. Among clinical and laboratory factors, the duration of CsA treatment (P = 0.003) and the duration of heavy proteinuria during CsA treatment (P = 0.024) were related to the development of CsA-induced tubulointerstitial lesions as determined by the univariate analyses. Indeed, CsA-induced tubulointerstitial lesions were found in 2 of 18 (11%) patients who had been treated with CsA for less than 24 months, but in 11 of 19 patients (58%) who had been treated for more than 24 months (P = 0.005). They were also found in 4 of 23 patients (17%) who had heavy proteinuria for less than 30 days during CsA treatment, but in 9 of 14 patients (64%) who had heavy proteinuria for more than 30 days (P = 0.006). Stepwise logistic-regression analysis revealed that the duration of CsA treatment for more than 24 months (chi2 = 6.203, P = 0.013) and the duration of heavy proteinuria during CsA treatment for more than 30 days (chi2 = 5.871, P = 0.015) were independent risk factors for the development of CsA-induced tubulointerstitial lesions.
  
  
  CONCLUSIONS
  Duration of the CsA treatment and the duration of heavy proteinuria during CsA treatment were independent significant risk factors for the development of CsA-induced tubulointerstitial lesions in children with MCNS who had been treated with long-term moderate-dose CsA.
authors.affiliation: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan. kidney@kobe-u.ac.jp
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Iijima
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hamahira
authors.forename: Ryojiro
authors.initials: R
authors.lastname: Tanaka
authors.forename: Akiko
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Kandai
authors.initials: K
authors.lastname: Nozu
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakamura
authors.forename: Norishige
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D001706:Biopsy; D002648:Child; D016572:Cyclosporine / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects*; D016015:Logistic Models; D008297:Male; D009395:Nephritis, Interstitial / Q000139:chemically induced* / Q000453:epidemiology* / Q000473:pathology; D009402:Nephrosis, Lipoid / Q000188:drug therapy* / Q000453:epidemiology* / Q000473:pathology; D011507:Proteinuria / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology; D012307:Risk Factors
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine