title: Pendrin is a novel autoantigen recognized by patients with autoimmune thyroid diseases.
abstract: BACKGROUND
  Pendrin is an apical protein of thyroid follicular cells, responsible for the efflux of iodide into the follicular lumen via an iodide-chloride transport mechanism. It is unknown whether pendrin is recognized by autoantibodies.
  
  
  OBJECTIVE
  Our objective was to examine the prevalence of pendrin antibodies in autoimmune thyroid diseases and compare with that of thyroglobulin, thyroperoxidase, TSH receptor, and sodium iodide symporter antibodies.
  
  
  METHODS
  In a prevalent case-control study, we analyzed the sera of 140 autoimmune thyroid disease cases (100 with Graves' disease and 40 with Hashimoto's thyroiditis) and 80 controls (50 healthy subjects, 10 patients with papillary thyroid cancer, 10 with systemic lupus erythematosus, and 10 with rheumatoid arthritis). Pendrin antibodies were measured by immunoblotting using extract of COS-7 cells transfected with pendrin and a rabbit polyclonal pendrin antibody.
  
  
  RESULTS
  Pendrin antibodies were found in 81% of the cases and 9% of controls (odds ratio = 44; P < 0.0001). Among cases, pendrin antibodies were more frequent and of higher titers in Hashimoto's thyroiditis than in Graves' disease. Pendrin antibodies correlated significantly with thyroglobulin, thyroperoxidase, and sodium iodide symporter antibodies but not with TSH receptor antibodies. Pendrin antibodies were equally effective as thyroglobulin and thyroperoxidase antibodies in diagnosis of autoimmune thyroid diseases, especially Hashimoto's thyroiditis.
  
  
  CONCLUSIONS
  The study identifies pendrin as a novel autoantigen recognized by patients with autoimmune thyroid diseases and proposes the use of pendrin antibodies as an accurate diagnostic tool.
authors.affiliation: Division of Regenerative Medicine and Therapeutics, Department of Genetics and Regenerative Medicine, Tottori University Graduate School of Medicine, Nishimachi 36-1, Yonago, Tottori 683-8504, Japan. ayoshida@grape.med.tottori-u.ac.jp
authors.forename: Akio
authors.initials: A
authors.lastname: Yoshida
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hisatome
authors.forename: Shinichi
authors.initials: S
authors.lastname: Taniguchi
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Shirayoshi
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Junichiro
authors.initials: J
authors.lastname: Miake
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Ohkura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Akama
authors.forename: Osamu
authors.initials: O
authors.lastname: Igawa
authors.forename: Chiaki
authors.initials: C
authors.lastname: Shigemasa
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kamijo
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Ikuyama
authors.forename: Patrizio
authors.initials: P
authors.lastname: Caturegli
authors.forename: Koichi
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000097:blood / Q000276:immunology* / Q000302:isolation & purification; D019556:COS Cells; D016022:Case-Control Studies; D002522:Chlorocebus aethiops; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000276:immunology*; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D000076988:Sulfate Transporters; D027981:Symporters / Q000276:immunology; D013954:Thyroglobulin / Q000276:immunology; D013967:Thyroiditis, Autoimmune / Q000097:blood* / Q000175:diagnosis / Q000276:immunology*; D000099209:Sodium-Iodide Symporters
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007453:Iodide Peroxidase; D033862:Iron-Binding Proteins; D026901:Membrane Transport Proteins; D000076988:Sulfate Transporters; D027981:Symporters; D013954:Thyroglobulin; D000099209:Sodium-Iodide Symporters; C085609:SLC26A4 protein, human; C056658:TPO protein, human