title: Antiproteinase 3- and antimyeloperoxidase-associated vasculitis.
abstract: Antiproteinase 3- and antimyeloperoxidase-associated vasculitis. Wegener's granulomatosis, microscopic polyangiitis, and idiopathic pauci-immune necrotizing crescentic glomerulonephritis (NCGN) are strongly associated with antineutrophil cytoplasmic autoantibodies (ANCAs) directed against either proteinase 3 (anti-PR3) or myeloperoxidase (anti-MPO). This has led some investigators to prefer combining these diseases under the common heading of ANCA-associated vasculitides. However, it is increasingly recognized that there are characteristic differences between patients with anti-PR3 and those with anti-MPO-associated vasculitis. This review focuses on the clinical, histopathologic, and possibly pathophysiologic differences between anti-PR3- and anti-MPO-associated vasculitis. Although there is considerable overlap, the anti-PR3- and anti-MPO-associated vasculitides are each characterized by particular clinical and histopathological findings. Extrarenal organ manifestations and respiratory tract granulomas occur more frequently in patients with anti-PR3 than in those with anti-MPO. Anti-PR3-positive patients with NCGN generally have a more dramatic deterioration of their renal function compared with anti-MPO-positive patients. The term "ANCA-associated vasculitis" is considered as a useful concept in the presence of systemic vasculitis. Likewise, in the presence of vasculitis, the terms "anti-PR3-associated vasculitis" and "anti-MPO-associated vasculitis" are useful concepts.
authors.affiliation: Department of Internal Medicine, Divisions of Nephrology and Clinical Immunology, University Hospital Groningen, Groningen, The Netherlands. c.f.m.franssen@int.azg.nl
authors.forename: C F
authors.initials: CF
authors.lastname: Franssen
authors.forename: C A
authors.initials: CA
authors.lastname: Stegeman
authors.forename: C G
authors.initials: CG
authors.lastname: Kallenberg
authors.forename: R O
authors.initials: RO
authors.lastname: Gans
authors.forename: P E
authors.initials: PE
authors.lastname: De Jong
authors.forename: S J
authors.initials: SJ
authors.lastname: Hoorntje
authors.forename: J W
authors.initials: JW
authors.lastname: Tervaert
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis / Q000276:immunology*; D006801:Humans; D007674:Kidney Diseases / Q000276:immunology; D053146:Myeloblastin; D009195:Peroxidase / Q000276:immunology*; D012140:Respiratory Tract Diseases / Q000276:immunology; D012697:Serine Endopeptidases / Q000276:immunology*; D014657:Vasculitis / Q000276:immunology* / Q000503:physiopathology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase; D012697:Serine Endopeptidases; D053146:Myeloblastin