title: Interferon-gamma ELISPOT detecting reactivity of T cells to TSH receptor peptides in Graves' disease.
abstract: OBJECTIVE
  While thyrotrophin receptor (TSHR) is recognized as the main autoantigen in Graves' disease (GD), the actual antigen specificity of T cells that infiltrate the thyroid and the orbit is unknown. Identifying T cell responses to TSHR peptides has been difficult in the past due to the low frequency of autoreactive T cells and to the diversity of the putative epitopes identified by proliferation assays.
  
  
  METHODS
  We used the interferon-gamma ELISPOT assay to identify T cell reactivity to TSHR peptides in patients with GD. Peripheral blood T cells were exposed in vitro to four pools of 10 overlapping TSHR peptides.
  
  
  RESULTS
  T cells from 11 of 31 (35%) patients with GD and 1 of 22 (4%) healthy controls reacted to at least one peptide pool (P = 0·009). Mean time since diagnosis was 3·2 years in responder patients and 5·6 years in nonresponders (P = 0·07). In two patients, T cell reactivity was observed shortly after radioiodine treatment and not thereafter.
  
  
  CONCLUSIONS
  Our findings demonstrate that the ELISPOT assay is effective to test T cell reactivity in patients with GD and that patients with GD have significantly more interferon-gamma responses towards TSHR peptides than controls. The data suggest that screening for T cell responses in patients with GD might be more efficient in recent-onset disease or after radioiodine treatment.
authors.affiliation: Faculty of Medicine, University Hospital Sherbrooke, Sherbrooke, QC, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Côté-Bigras
authors.forename: Audrey
authors.initials: A
authors.lastname: Dionne
authors.forename: Patrick
authors.initials: P
authors.lastname: Asselin-Mullen
authors.forename: Coralie
authors.initials: C
authors.lastname: Leblicq
authors.forename: Diane
authors.initials: D
authors.lastname: Rottembourg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D002648:Child; D058501:Enzyme-Linked Immunospot Assay / Q000379:methods*; D006111:Graves Disease / Q000276:immunology* / Q000532:radiotherapy; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology* / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008875:Middle Aged; D010455:Peptides / Q000276:immunology*; D011989:Receptors, Thyrotropin / Q000276:immunology*; D015203:Reproducibility of Results; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013997:Time Factors; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes; D010455:Peptides; D011989:Receptors, Thyrotropin; D007371:Interferon-gamma