title: The evolution of morphological variants of focal segmental glomerulosclerosis: a repeat biopsy-based observation.
abstract: BACKGROUND
  The Columbia classification employs a systematic, hierarchical approach to define five mutually exclusive variants. Studies have demonstrated differences in baseline clinical characteristics and outcomes among the Columbia classification variants. However, the evolution of the Columbia classification variants of primary focal segmental glomerulosclerosis (FSGS) is unclear. We assessed the evolution of morphological variants in FSGS based on repeat native renal biopsies.
  
  
  METHODS
  Twenty-four patients (18 male, 6 female) with idiopathic FSGS who underwent more than one renal biopsy were enrolled in this study; three of these patients underwent three renal biopsies. The patients' clinicopathological features were reviewed. The subtypes of FSGS (2004 Columbia classification) included the collapsing, tip, cellular, perihilar and not otherwise specified (NOS) variants. The evolution of the Columbia classification variants of primary FSGS in each patient was evaluated.
  
  
  RESULTS
  The interval between the first and second renal biopsy was 21.95 ± 24.33 months. No significant differences in laboratory data were noted between the first and second renal biopsy. At the first renal biopsy, 5 patients were classified with collapsing, 5 with tip, 6 with cellular, 2 with perihilar and 6 with NOS variants. At the second renal biopsy, 3 patients were classified with collapsing, 3 with tip lesion, 4 with cellular, 1 with perihilar and 13 with NOS variants. Subtype changes from the first to repeat biopsies occurred in 11 patients, 9 of which progressed from other variants to the NOS variant.
  
  
  CONCLUSIONS
  Repeat renal biopsies are a useful tool for observing FSGS histological changes. The transformation from other subtypes to the NOS variant was the most common change; these alterations were accompanied by clinical progression.
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Shaoshan
authors.initials: S
authors.lastname: Liang
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Liu
authors.affiliation: National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School Of Medicine, Nanjing 210002, P.R. China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Zeng
mesh_terms: D000293:Adolescent; D000328:Adult; D001706:Biopsy; D018450:Disease Progression; D005260:Female; D005923:Glomerulosclerosis, Focal Segmental / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D007668:Kidney / Q000473:pathology; D008297:Male; D016896:Treatment Outcome; D055815:Young Adult
keywords: Colombia classification; FSGS; histological change; renal repeat biopsy