title: Histopathologic classification of ANCA-associated glomerulonephritis.
abstract: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is the most common cause of rapidly progressive glomerulonephritis worldwide, and the renal biopsy is the gold standard for establishing the diagnosis. Although the prognostic value of the renal biopsy in ANCA-associated glomerulonephritis is widely recognized, there is no consensus regarding its pathologic classification. We present here such a pathologic classification developed by an international working group of renal pathologists. Our classification proposes four general categories of lesions: Focal, crescentic, mixed, and sclerotic. To determine whether these lesions have predictive value for renal outcome, we performed a validation study on 100 biopsies from patients with clinically and histologically confirmed ANCA-associated glomerulonephritis. Two independent pathologists, blinded to patient data, scored all biopsies according to a standardized protocol. Results show that the proposed classification system is of prognostic value for 1- and 5-year renal outcomes. We believe this pathologic classification will aid in the prognostication of patients at the time of diagnosis and facilitate uniform reporting between centers. This classification at some point might also provide means to guide therapy.
authors.affiliation: Department of Pathology, Leiden University Medical Center, Leiden, Netherlands. a.e.berden@lumc.nl
authors.forename: Annelies E
authors.initials: AE
authors.lastname: Berden
authors.forename: Franco
authors.initials: F
authors.lastname: Ferrario
authors.forename: E Christiaan
authors.initials: EC
authors.lastname: Hagen
authors.forename: David R
authors.initials: DR
authors.lastname: Jayne
authors.forename: J Charles
authors.initials: JC
authors.lastname: Jennette
authors.forename: Kensuke
authors.initials: K
authors.lastname: Joh
authors.forename: Irmgard
authors.initials: I
authors.lastname: Neumann
authors.forename: Laure-Hélène
authors.initials: LH
authors.lastname: Noël
authors.forename: Charles D
authors.initials: CD
authors.lastname: Pusey
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Waldherr
authors.forename: Jan A
authors.initials: JA
authors.lastname: Bruijn
authors.forename: Ingeborg M
authors.initials: IM
authors.lastname: Bajema
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D001706:Biopsy; D005260:Female; D005921:Glomerulonephritis / Q000145:classification / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology*; D007684:Kidney Tubules / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic