title: ANCA-associated vasculitis - clinical utility of using ANCA specificity to classify patients.
abstract: The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a heterogeneous group of rare syndromes characterized by necrotizing inflammation of small and medium-sized blood vessels and the presence of ANCAs. Several clinicopathological classification systems exist that aim to define homogeneous groups among patients with AAV, the main syndromes being microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic GPA (EGPA). Two main types of ANCA can be detected in patients with AAV. These ANCAs are defined according to their autoantigen target, namely leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). Patients with GPA are predominantly PR3-ANCA-positive, whereas those with MPA are predominantly MPO-ANCA-positive, although ANCA specificity overlaps only partially with these clinical syndromes. Accumulating evidence suggests that ANCA specificity could be better than clinical diagnosis for defining homogeneous groups of patients, as PR3-ANCA and MPO-ANCA are associated with different genetic backgrounds and epidemiology. ANCA specificity affects the phenotype of clinical disease, as well as the patient's initial response to remission-inducing therapy, relapse risk and long-term prognosis. Thus, the classification of AAV by ANCA specificity rather than by clinical diagnosis could convey clinically useful information at the time of diagnosis.
authors.affiliation: Thoracic Disease Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First Street, Rochester, Minnesota 55905, USA.|European University of Brittany and Brest University Hospital, Boulevard Tanguy Prigent, Brest 29609, France.
authors.forename: Divi
authors.initials: D
authors.lastname: Cornec
authors.affiliation: European University of Brittany and Brest University Hospital, Boulevard Tanguy Prigent, Brest 29609, France.|Division of Nephrology, Mayo Clinic, 200 First Street, Rochester, Minnesota 55905, USA.
authors.forename: Emilie
authors.initials: E
authors.lastname: Cornec-Le Gall
authors.affiliation: Division of Nephrology, Mayo Clinic, 200 First Street, Rochester, Minnesota 55905, USA.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Fervenza
authors.affiliation: Thoracic Disease Research Unit, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First Street, Rochester, Minnesota 55905, USA.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Specks
mesh_terms: D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000097:blood / Q000145:classification* / Q000175:diagnosis* / Q000276:immunology; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015267:Churg-Strauss Syndrome / Q000175:diagnosis; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis; D006801:Humans; D007155:Immunologic Factors / Q000097:blood*; D007249:Inflammation / Q000097:blood; D055953:Microscopic Polyangiitis / Q000175:diagnosis; D053146:Myeloblastin / Q000097:blood; D009195:Peroxidase / Q000097:blood; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D015415:Biomarkers; D007155:Immunologic Factors; D009195:Peroxidase; D053146:Myeloblastin