title: ANCA serotype and histopathological classification for the prediction of renal outcome in ANCA-associated glomerulonephritis.
abstract: BACKGROUND
  The phenotype of renal involvement in anti-neutrophil cytoplasmic antibodies (ANCA) vasculitis has a major influence on survival, and histological subgrouping of diagnostic renal biopsies has been proposed to aid in the prediction of renal outcome. We aimed to validate this histological subgrouping and to investigate the additional value of ANCA serotype in the prediction of renal outcome.
  
  
  METHODS
  Data were retrospectively collected from the time of diagnosis by systematic review of medical records from 136 patients with renal biopsies recruited to cohorts from the UK and Spain, over 15 years. The end point, renal survival, was the composite of end-stage renal disease (ESRD) or death from any cause. The occurrence of ESRD, Stage 4 Kidney Disease Outcomes Quality Initiative-Chronic Kidney Disease, was assessed separately, in order to establish a severity index risk of chronic kidney disease.
  
  
  RESULTS
  Renal survival at 5 years was 96% in the focal, 86% in the crescentic, 81% in the mixed and 61% in the sclerotic subgroups (P = 0.03). Myeloperoxidase (MPO)-ANCA was associated with more severe disease when compared with PR3-ANCA, as demonstrated by a lower frequency of focal and higher frequency of sclerotic subgroups, by more advanced interstitial fibrotic change and by lower glomerular filtration rate at diagnosis and worse renal function at 1 and 2 years.
  
  
  CONCLUSIONS
  We have confirmed the predictive value for renal survival of the ANCA vasculitis histology classification in a multi-centre study. We found a worse renal outcome in patients with tubulointerstitial fibrosis and atrophy. MPO-ANCA positive patients had a worse renal prognosis due to more severe glomerular injury. These results contribute to patient stratification in renal vasculitis for therapeutic, epidemiological and basic research.
authors.affiliation: Division of Nephrology, Department of Medicine, University of Cambridge, Vasculitis and Lupus Clinic, Addenbrooke's Hospital, Cambridge, UK Servicio de Nefrología y Trasplante Renal, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universidad de Barcelona, Barcelona, Spain.
authors.forename: Luis F
authors.initials: LF
authors.lastname: Quintana
authors.affiliation: Servicio de Nefrología y Trasplante Renal, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universidad de Barcelona, Barcelona, Spain.
authors.forename: Nuria S
authors.initials: NS
authors.lastname: Peréz
authors.affiliation: Division of Nephrology, Department of Medicine, University of Cambridge, Vasculitis and Lupus Clinic, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Erika
authors.initials: E
authors.lastname: De Sousa
authors.affiliation: Servicio de Nefrología y Trasplante Renal, Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universidad de Barcelona, Barcelona, Spain.
authors.forename: Lida M
authors.initials: LM
authors.lastname: Rodas
authors.affiliation: Department of Histopathology, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Meryl H
authors.initials: MH
authors.lastname: Griffiths
authors.affiliation: Department of Pathology, Hospital Clinic, Barcelona, Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Solé
authors.affiliation: Division of Nephrology, Department of Medicine, University of Cambridge, Vasculitis and Lupus Clinic, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: David
authors.initials: D
authors.lastname: Jayne
mesh_terms: D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000276:immunology; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D005260:Female; D005921:Glomerulonephritis / Q000188:drug therapy / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009195:Peroxidase / Q000276:immunology; D012189:Retrospective Studies; D065288:Serogroup; D012720:Severity of Illness Index
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase
keywords: ANCA; glomerulonephritis; histopathology; outcome; vasculitis