title: Validation of the Japanese histologic classification 2013 of immunoglobulin A nephropathy for prediction of long-term prognosis in a Japanese single-center cohort.
abstract: BACKGROUND
  A new Japanese histologic classification (JHC) of immunoglobulin A nephropathy (IgAN) for prediction of long-term prognosis was proposed in 2013. The goal of this study was to validate the JHC system in a Japanese single-center cohort.
  
  
  METHODS
  A retrospective study was conducted in 198 Japanese adult patients with IgAN. Clinical findings including blood pressure, urinary protein, estimated glomerular filtration rate (eGFR), and outcomes were evaluated in these patients. The glomerular lesion percentage score (GLPS) [number of glomeruli with cellular crescents, fibrocellular crescents, global sclerosis, segmental sclerosis, or fibrous crescents/number of total obtained glomeruli × 100 (%)] was assessed in each patient and categorized into histologic grades (HGs) of HG1 (<25 %), HG2 (25-49 %), and HG3/4 (≥50 %). Associations of GLPS (HG) with disease progression (50 % eGFR decline or end-stage renal disease requiring dialysis) within 10 years after biopsy and the rate of annual eGFR decline were examined.
  
  
  RESULTS
  During a median follow-up period of 12.0 years after biopsy, disease progression occurred in 12.8 % (12/94) of HG1 patients, 32.3 % (21/65) of HG2 patients, and 46.2 % (18/39) of HG3/4 patients. The risk of disease progression was significantly higher in the HG2 and HG3/4 groups than in the HG1 group (odds ratios: 3.3 and 5.9 vs. 1). A higher GLPS was significantly associated with a higher risk of disease progression and a greater annual eGFR decline.
  
  
  CONCLUSIONS
  The newly proposed JHC system 2013 based on GLPS (HG) was well correlated with long-term prognosis in our cohort of Japanese adult patients with IgAN.
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan. ryuta-s@jichi.ac.jp.|Division of Nephrology, Department of Internal Medicine, Jichi Medical University Graduate School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan. ryuta-s@jichi.ac.jp.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Sato
authors.affiliation: Department of Pathology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Joh
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Komatsuda
authors.affiliation: Department of Nephrology and Dialysis, Akita Kumiai General Hospital, Akita, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtani
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Okuyama
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Togashi
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Omokawa
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Mizuho
authors.initials: M
authors.lastname: Nara
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Jichi Medical University Graduate School of Medicine, Shimotsuke, Tochigi, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nagata
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Jichi Medical University Graduate School of Medicine, Shimotsuke, Tochigi, Japan.|Department of Internal Medicine, Utsunomiya Social Insurance Hospital, Utsunomiya, Tochigi, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kusano
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sawada
authors.affiliation: Department of Hematology, Nephrology, and Rheumatology, Akita University Graduate School of Medicine, Akita, Japan.|Department of Life Science, Akita University Graduate School of Engineering and Resource Science, Akita, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Wakui
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D018450:Disease Progression; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D005922:Glomerulonephritis, IGA / Q000145:classification* / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007564:Japan; D007678:Kidney Glomerulus / Q000473:pathology*; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria / Q000652:urine; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
keywords: IgA nephropathy; Japanese histologic classification; Long-term prognosis