title: Renal biopsy criterion in idiopathic nephrotic syndrome with microscopic hematuria at onset.
abstract: BACKGROUND
  The criterion for performing a renal biopsy in children with idiopathic nephrotic syndrome (NS) showing microscopic hematuria at onset remains controversial.
  
  
  METHODS
  To determine an adequate renal biopsy criterion in children with NS showing hematuria, the optimal cutoff for the maximum red blood cell (RBC) range in urine sediment to separate minimal change disease (MCD) from other glomerular changes was obtained by receiver operating characteristic analysis. We studied 29 children with NS showing hematuria who were screened from 1,320 patients who underwent renal biopsies between January 2001 and September 2011. Patients were divided into two groups according to the cutoff value to verify its validity.
  
  
  RESULTS
  The optimal maximum RBC range was 30-49/high-power field (HPF). In group 1 (RBC ≤29/HPF, n = 14), 3 patients showed nephritis and the other 11 patients showed MCD. In group 2 (RBC ≥30/HPF, n = 15), 1 patient showed focal segmental glomerulosclerosis, 12 showed nephritis, and the other 2 showed MCD. These findings indicated that the ratio of non-MCD/MCD was significantly higher in group 2 than in group 1 (P < 0.01).
  
  
  CONCLUSIONS
  The use of maximum RBC range (30-49/HPF) for a criterion of renal biopsy in patients with NS showing hematuria may be reasonable for clinical practice.
authors.affiliation: Department of Pediatrics, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan.
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Hama
authors.forename: Koichi
authors.initials: K
authors.lastname: Nakanishi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shima
authors.forename: Masashi
authors.initials: M
authors.lastname: Sato
authors.forename: Hironobu
authors.initials: H
authors.lastname: Mukaiyama
authors.forename: Hiroko
authors.initials: H
authors.lastname: Togawa
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hamahira
authors.forename: Ryojiro
authors.initials: R
authors.lastname: Tanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kaito
authors.forename: Kandai
authors.initials: K
authors.lastname: Nozu
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Iijima
authors.forename: Norishige
authors.initials: N
authors.lastname: Yoshikawa
mesh_terms: D001706:Biopsy; D002648:Child; D004906:Erythrocyte Count; D005260:Female; D006417:Hematuria / Q000209:etiology / Q000652:urine; D006801:Humans; D007668:Kidney / Q000473:pathology*; D008297:Male; D009404:Nephrotic Syndrome / Q000150:complications / Q000473:pathology* / Q000652:urine; D012189:Retrospective Studies