title: Sensitive enzyme-linked immunosorbent assay for measurement of autoantibodies to human thyroid peroxidase.
abstract: The development of a sensitive assay for detection of autoantibodies against one of the major thyroid antigens, thyroid peroxidase (TPO), is described. TPO was purified from human thyroid tissue by: (1) isolation of thyroid microsomes using homogenization and differential centrifugation, (2) solubilization of membrane proteins by Zwittergent 3-14, and (3) anion exchange liquid chromatography on a FPLC Mono Q column. Autoantibodies against TPO (TPO-Ab) were measured using an enzyme-linked immunosorbent assay (ELISA) with serum samples diluted 1:100. Standards containing 70, 7, 0.7, 0.02 and 0 U ml-1 TPO-Ab were employed (reference standard code 66/387 NIBSC, London, UK). The detection limit was 0.02 U ml-1 corresponding to 2 U ml-1 in undiluted serum. The inter- and intra-assay coefficients of variation were 8.6% and 5.3%. In 109 healthy control subjects TPO-Ab was found in 9 (8.3%), while 43 (97.7%) out of 44 patients with newly diagnosed untreated Graves' disease had detectable TPO-Ab in serum. All of 16 patients with newly diagnosed spontaneously developing primary hypothyroidism had circulating TPO-Ab (range 16-7000 U ml-1). The new assay is a valuable tool for evaluation of thyroid autoimmunity in individual patients and for studying the epidemiology of thyroid autoimmunity.
authors.affiliation: Department of Internal Medicine and Endocrinology, Aalborg Regional Hospital, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Laurberg
authors.forename: K M
authors.initials: KM
authors.lastname: Pedersen
authors.forename: E
authors.initials: E
authors.lastname: Vittinghus
authors.forename: S
authors.initials: S
authors.lastname: Ekelund
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology*; D007453:Iodide Peroxidase / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012016:Reference Values
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007453:Iodide Peroxidase