title: Prevalence of autoantibodies in SAPHO syndrome: a single-center study of 90 patients.
abstract: OBJECTIVE
  To determine the prevalence of the most often tested autoantibodies in synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.
  
  
  METHODS
  We identified 90 patients seen in our unit between June 2002 and June 2009, and diagnosed according to the proposed criteria for SAPHO syndrome. Demographic and clinical data were collected as well as immunological results, including antinuclear, antithyroid peroxydase (TPO), antithyroid globulin (Tg), antigastric parietal cell, antismooth muscle, antimitochondria, and anti-liver-kidney microsome (LKM) antibodies. Anticyclic citrullinated peptide (CCP) antibodies were analyzed in 69 patients, antibodies to soluble extractable nuclear antigens in 43, anti-double-stranded DNA (dsDNA) antibodies in 22 [depending on the type of fluorescence of antinuclear antibody (ANA)], and antiendomysium antibodies in 55.
  
  
  RESULTS
  Autoantibodies were found in 20 patients (22.2%): 14 patients (15.5%) had positive ANA (titer >/= 1/160); among them, 10 (11%) patients never took a lupus-inducing drug. Antithyroid antibodies (anti-TPO and/or anti-Tg antibodies) were found in only 3 patients (3.3%). Three patients (3.3%) were positive for antigastric parietal cell antibodies and 4 (4.4%) were weakly positive for antismooth muscle antibodies. Antimitochondria and LKM antibodies were negative in all 90 patients. Anti-CCP and anti-dsDNA antibodies were negative in the 69 and 22 patients tested, respectively. One out of 43 patients (2.3%) had anti-SSA antibodies. Antiendomysium antibodies were negative in the 55 patients tested.
  
  
  CONCLUSIONS
  Our study indicates an increased prevalence of autoantibodies in SAPHO syndrome, with no specific profile. We failed to confirm the reports of an increased prevalence of antithyroid antibodies. These results tend to support a link between autoimmunity and SAPHO syndrome.
authors.affiliation: Department of Rheumatology and Department of Immunology, Bichat Teaching Hospital, Paris, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Grosjean
authors.forename: Margarita
authors.initials: M
authors.lastname: Hurtado-Nedelec
authors.forename: Pascale
authors.initials: P
authors.lastname: Nicaise-Roland
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Ferreyra-Dillon
authors.forename: Caroline
authors.initials: C
authors.lastname: Bollet
authors.forename: Emilie
authors.initials: E
authors.lastname: Quintin
authors.forename: Philippe
authors.initials: P
authors.lastname: Dieude
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Palazzo
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Wattiaux
authors.forename: Marcel-Francis
authors.initials: MF
authors.lastname: Kahn
authors.forename: Olivier
authors.initials: O
authors.lastname: Meyer
authors.forename: Sylvie
authors.initials: S
authors.lastname: Chollet-Martin
authors.forename: Gilles
authors.initials: G
authors.lastname: Hayem
mesh_terms: D020083:Acquired Hyperostosis Syndrome / Q000097:blood / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000097:blood; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology*; D004247:DNA / Q000276:immunology; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000276:immunology; D010295:Parietal Cells, Gastric / Q000276:immunology; D010456:Peptides, Cyclic / Q000276:immunology; D011446:Prospective Studies; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D010456:Peptides, Cyclic; C060729:anti-liver kidney microsome antibody; C006606:anti-thyroglobulin; C487763:cyclic citrullinated peptide; D004247:DNA; C056658:TPO protein, human; D007453:Iodide Peroxidase