title: Characterization of thyroglobulin epitopes in patients with autoimmune and non-autoimmune thyroid diseases using recombinant human monoclonal thyroglobulin autoantibodies.
abstract: BACKGROUND
  Thyroglobulin (Tg) epitopes of serum Tg autoantibodies (TgAb) have been characterized using inhibition of Tg binding by human monoclonal TgAb in autoimmune thyroid diseases (AITD) [Hashimoto's thyroiditis (HT) and Graves' disease (GD)] but not in non-AITD [nontoxic multinodular goiter (NTMG) and papillary thyroid carcinoma (PTC)].
  
  
  OBJECTIVE
  Our objective was to compare Tg epitopes of serum TgAb from patients with AITD, non-AITD, and PTC associated with histological thyroiditis (PTC-T) using inhibition of Tg binding by four recombinant human TgAb-Fab (epitopic regions A-D).
  
  
  METHODS
  Inhibition of Tg binding of 24 HT, 25 GD, 19 NTMG, 15 PTC, and 25 PTC-T TgAb-positive sera by each TgAb-Fab was evaluated in ELISA. Inhibition by the pool of the four TgAb-Fab was evaluated using labeled Tg.
  
  
  RESULTS
  Levels of inhibition were different for TgAb-Fab regions A (P = 0.001), B (0.007), and D (0.011). Inhibition by region A TgAb-Fab was significantly higher in HT, GD, and PTC-T than in NTMG and PTC patients. Inhibition levels by region B TgAb-Fab were significantly higher in HT compared with NTMG and PTC patients and in GD compared with NTMG patients. Inhibition by D region TgAb-Fab was significantly lower in NTMG than in the other groups. Inhibition by the pool ranged from 44% (NTMG) to 72% (GD).
  
  
  CONCLUSIONS
  The pattern of Tg recognition is similar when HT patients are compared to GD and NTMG to PTC patients and differs when AITD are compared with non-AITD patients. In PTC-T patients, it is similar to that of AITD patients.
authors.affiliation: Department of Endocrinology, University Hospital of Pisa, Via Cisanello 2, 56124 Pisa, Italy. latrofaf@libero.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Latrofa
authors.forename: Debora
authors.initials: D
authors.lastname: Ricci
authors.forename: Lucia
authors.initials: L
authors.lastname: Grasso
authors.forename: Paolo
authors.initials: P
authors.lastname: Vitti
authors.forename: Lucio
authors.initials: L
authors.lastname: Masserini
authors.forename: Fulvio
authors.initials: F
authors.lastname: Basolo
authors.forename: Clara
authors.initials: C
authors.lastname: Ugolini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mascia
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini
authors.forename: Aldo
authors.initials: A
authors.lastname: Pinchera
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D001667:Binding, Competitive / Q000276:immunology; D002291:Carcinoma, Papillary / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000032:analysis; D006044:Goiter, Nodular / Q000276:immunology*; D006111:Graves Disease / Q000276:immunology*; D050031:Hashimoto Disease / Q000276:immunology*; D006801:Humans; D011994:Recombinant Proteins; D013954:Thyroglobulin / Q000276:immunology*; D013964:Thyroid Neoplasms / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D000939:Epitopes; D011994:Recombinant Proteins; D013954:Thyroglobulin