title: Clinical and histological features of lupus nephritis in Japan: A cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR).
abstract: OBJECTIVE
  The clinical and histological features of lupus nephritis (LN) are highly variable, depending on race and ethnicity. The Japan Renal Biopsy Registry (J-RBR) is a nationwide registry of renal biopsies. Here, we report a cross-sectional analysis of Japanese LN using the J-RBR database.
  
  
  METHODS
  Out of 18 463 patients registered in the J-RBR, 331 LN patients, who received renal biopsy for the first time, were extracted and their clinical features were analyzed according to the ISN/RPS 2003 classification.
  
  
  RESULTS
  The median age of the 331 LN patients was 37 years (women, 81.3%). The frequencies of each of the ISN/RPS Classes were as follows: I, 1.2%; II, 7.9%; III (±V), 25.1%; IV-S (±V), 13.0%; IV-G (±V), 31.1%; V, 20.8%; and VI, 0.9%. The level of proteinuria and the prevalence of nephrotic syndrome were highest for Class IV-G (±V). When Classes I, II, and VI were excluded from the analysis, Class IV-G (±V) was significantly associated with a lower eGFR and severer haematuria than the other classes.
  
  
  CONCLUSIONS
  This nationwide study revealed that Class IV-G (±V) was the most prevalent form of LN in Japan and was associated with a severe clinical renal presentation.
authors.affiliation: Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: Keiju
authors.initials: K
authors.lastname: Hiromura
authors.affiliation: Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Ikeuchi
authors.affiliation: Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kayakabe
authors.affiliation: Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sugiyama
authors.affiliation: Department of Kidney and Vascular Pathology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Nagata
authors.affiliation: Clinical Pharmacology and Therapeutics, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.affiliation: Division of Nephrology, Kanazawa Medical University School of Medicine, Uchinada, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yokoyama
authors.affiliation: Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Maebashi, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Nojima
mesh_terms: D000328:Adult; D001706:Biopsy; D003430:Cross-Sectional Studies; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D008181:Lupus Nephritis / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D012042:Registries
keywords: ISN/RPS classification; lupus nephritis; renal biopsy registry; systemic lupus erythematosus