title: Detection of Anti-Pentraxin-3 Autoantibodies in ANCA-Associated Vasculitis.
abstract: OBJECTIVE
  Pentraxin 3 (PTX3), in common with myeloperoxidase and proteinase 3, is stored in human neutrophil granules and is expressed on apoptotic neutrophil surface. We therefore investigated the presence of anti-PTX3 autoantibodies (aAbs) in the sera of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) patients.
  
  
  METHODS
  Presence of anti-PTX3 autoantibodies was analysed by a specific enzyme-linked immunosorbent assay in sera from 150 patients with microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA), and in sera of 227 healthy subjects (HS), 40 systemic sclerosis (SSc) patients, and 25 giant cell arteritis patients (GCA). Using indirect immunofluorescence on fixed human neutrophils, we also analyzed the staining pattern associated with the presence of anti-PTX3 aAbs.
  
  
  RESULTS
  Anti-PTX3 aAbs were detected in 56 of 150 (37.3%) of the AAV patients (versus 12 of 227 (5.3%) of HS, p<0.001) and, interestingly, in 7 of 14 MPO and PR3 ANCA negative AAV patients. Moreover, by indirect immunofluorescence on fixed neutrophils, anti-PTX3 aAbs gave rise to a specific cytoplasmic fluorescence pattern distinct from the classical cytoplasmic (c-ANCA), perinuclear (p-ANCA), and atypical (a-ANCA) pattern. Anti-PTX3 aAbs levels were higher in patients with active AAV as compared to patients with inactive disease.
  
  
  CONCLUSIONS
  Our work suggests that PTX3 is as a novel ANCA antigen. Anti-PTX3 aAbs appear thus as a promising novel biomarker in the diagnosis of AAV, including in patients without detectable MPO and PR3 ANCA.
authors.affiliation: Nephrology Department, University Hospital of Angers, Angers, France.|LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Simon
authors.affiliation: Nephrology Department, University Hospital of Angers, Angers, France.|LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Subra
authors.affiliation: Internal Medicine Department, University Hospital of Montpellier, Monptellier, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Guilpain
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.|Immunology and Allergology Laboratory, University Hospital of Angers, Angers, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Jeannin
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Pascale
authors.initials: P
authors.lastname: Pignon
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.|Immunology and Allergology Laboratory, University Hospital of Angers, Angers, France.
authors.forename: Simon
authors.initials: S
authors.lastname: Blanchard
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Erwan
authors.initials: E
authors.lastname: Garo
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Jaillon
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.|Immunology and Allergology Laboratory, University Hospital of Angers, Angers, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Chevailler
authors.affiliation: Immunology and Allergology Laboratory, University Hospital of Angers, Angers, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Renier
authors.affiliation: National Referral Center for Rare Systemic Autoimmune Diseases, Department of Internal Medicine, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Puéchal
authors.affiliation: Immunology and Inflammation Research Laboratory, Istituto Clinico Humanitas, Milano, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bottazzi
authors.affiliation: Immunology and Inflammation Research Laboratory, Istituto Clinico Humanitas, Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Mantovani
authors.affiliation: LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.|Immunology and Allergology Laboratory, University Hospital of Angers, Angers, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Delneste
authors.affiliation: Nephrology Department, University Hospital of Angers, Angers, France.|LUNAM University, Angers University, Cancer Research Center Nantes-Angers, Angers, France; Inserm, UMR 892, Angers, France; CNRS, UMR 6299, Angers, France; LabEx IGO, Angers, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Augusto
mesh_terms: D000328:Adult; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000276:immunology*; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D000683:Serum Amyloid P-Component / Q000276:immunology*; D000099153:Pentraxins
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D002097:C-Reactive Protein; D000683:Serum Amyloid P-Component; D000099153:Pentraxins