Characterization of thyroglobulin epitopes in Sardinian adults and juveniles with Hashimoto's thyroiditis: evidence against a major effect of age and genetic background on B-cell epitopes

Clin Endocrinol (Oxf). 2010 Jul;73(1):110-3. doi: 10.1111/j.1365-2265.2009.03748.x. Epub 2009 Nov 11.


Background: Using recombinant human monoclonal thyroglobulin antibodies expressed as Fab molecules (TgAb-Fab), we have recently confirmed the restriction of Tg epitopes in Hashimoto's thyroiditis (HT).

Objective: To investigate Tg epitopes of serum TgAb in HT adults and HT juveniles from a geographically isolated area (Sardinia).

Design and patients: Serum TgAb of 39 Sardinian HT adults, 53 Sardinian HT juveniles and 45 non-Sardinian HT adults were evaluated. The binding of serum TgAb to Tg in ELISA was inhibited by four recombinant human TgAb-Fab, identifying Tg epitopic regions A-D. The percentage of Tg binding inhibition was calculated comparing the binding of serum TgAb in presence of each TgAb-Fab with that in its absence.

Results: In the whole cohort of 137 patients, A region TgAb-Fab induced the highest levels of inhibition (55.3 +/- 17.8%) (mean +/- SD). Lower levels of inhibition were induced by TgAb-Fab of regions B (27.8 +/- 25.8%), C (26.8 +/- 24.6%) and D (17.5 +/- 18.4%). In Sardinian HT adults inhibition by TgAb-Fab of regions A, B and C were comparable to Sardinian HT juveniles; the marginal D region TgAb-Fab induced a slightly higher inhibition (22.1 vs. 13.8%; P = 0.034) in the former than in the latter group. In Sardinian and non-Sardinian HT adults inhibitions by the four TgAb-Fab were similar.

Conclusions: In HT, the Tg epitope pattern of serum TgAb was similar in juveniles and adults from a geographically restricted area and in two adult populations from different geographical areas. Thus, in HT, neither age nor genetic background appear to influence B-cell epitopes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antigen-Antibody Reactions / drug effects
  • Autoantigens / immunology
  • Child
  • Epitopes, B-Lymphocyte / immunology*
  • Ethnicity / genetics
  • Female
  • Hashimoto Disease / immunology*
  • Humans
  • Immunoglobulin Fab Fragments / pharmacology
  • Iodide Peroxidase / immunology
  • Iron-Binding Proteins / immunology
  • Italy
  • Male
  • Thyroglobulin / immunology*
  • White People / genetics


  • Autoantigens
  • Epitopes, B-Lymphocyte
  • Immunoglobulin Fab Fragments
  • Iron-Binding Proteins
  • Thyroglobulin
  • TPO protein, human
  • Iodide Peroxidase