title: Proteinase 3-ANCA Vasculitis versus Myeloperoxidase-ANCA Vasculitis.
abstract: In patients with GN or vasculitis, ANCAs are directed against proteinase 3 (PR3) or myeloperoxidase (MPO). The differences between PR3-ANCA-associated vasculitis (AAV) and MPO-AAV described in the past have been supplemented during the last decade. In this review, we discuss the differences between these two small-vessel vasculitides, focusing especially on possible etiologic and pathophysiologic differences. PR3-AAV is more common in northern parts of the world, whereas MPO-AAV is more common in southern regions of Europe, Asia, and the Pacific, with the exception of New Zealand and Australia. A genetic contribution has been extensively studied, and there is a high prevalence of the HLA-DPB1*04:01 allele in patients with PR3-AAV as opposed to patients with MPO-AAV and/or healthy controls. Histologically, MPO-AAV and PR3-AAV are similar but show qualitative differences when analyzed carefully. Clinically, both serotypes are difficult to distinguish, but quantitative differences are present. More organs are affected in PR3-AAV, whereas renal limited vasculitis occurs more often in patients with MPO-AAV. For future clinical trials, we advocate classifying patients by ANCA serotype as opposed to the traditional disease type classification.
authors.affiliation: Clinical and Experimental Immunology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Marc
authors.initials: M
authors.lastname: Hilhorst
authors.affiliation: Clinical and Experimental Immunology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Pieter
authors.initials: P
authors.lastname: van Paassen
authors.affiliation: Clinical and Experimental Immunology, Maastricht University, Maastricht, The Netherlands jw.cohentervaert@maastrichtuniversity.
authors.forename: Jan Willem Cohen
authors.initials: JW
authors.lastname: Tervaert
mesh_terms: D000818:Animals; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000175:diagnosis / Q000188:drug therapy / Q000201:enzymology*; D004195:Disease Models, Animal; D006801:Humans; D053146:Myeloblastin / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism*
chemical_list: D009195:Peroxidase; D053146:Myeloblastin
keywords: ANCA; glomerulonephritis; vasculitis