title: Increased concentration of T-cell receptor rearrangement excision circles (TREC) in peripheral blood in Graves' disease.
abstract: BACKGROUND
  T-cell receptor rearrangement excision circles (TREC) are circular DNA molecules generated during T-cell maturation in the thymus. Recent studies suggested that a decreased TREC concentration in peripheral blood may be a general feature of autoimmunity. Our purpose was to assess the TREC concentration in Graves' disease (GD).
  
  
  METHODS
  TREC concentration was assessed by real time PCR in DNA samples isolated from peripheral blood leucocytes among younger (n = 94, age range 6-29 years) and older patients with GD (n = 93, age range 57-80 years) and age-matched controls (n = 206).
  
  
  RESULTS
  TREC concentration decreased with age in all subjects, but it was significantly higher in GD compared with controls (P = 9·4 × 10(-10) ). TREC concentration was higher (P = 0·0038) in hyperthyroid (n = 78) than euthyroid (n = 82) patients with GD, but in both groups, it remained increased relative to controls (P = 2·2 × 10(-11) and P = 4·4 ×10(-7) , respectively).
  
  
  CONCLUSIONS
  Patients with GD, particularly those with hyperthyroidism, have increased concentration of TREC which may suggest increased rather than decreased thymic activity. Thus, GD does not follow the paradigm suggested for other autoimmune disorders which links autoimmunity with thymic senescence.
authors.affiliation: Department of Medical Genetics, Centre for Biostructure, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Strawa
authors.forename: Anna
authors.initials: A
authors.lastname: Markowska
authors.forename: Piotr
authors.initials: P
authors.lastname: Miśkiewicz
authors.forename: Aleksander
authors.initials: A
authors.lastname: Kuś
authors.forename: Urszula
authors.initials: U
authors.lastname: Ambroziak
authors.forename: Konrad
authors.initials: K
authors.lastname: Szymański
authors.forename: Renata
authors.initials: R
authors.lastname: Zbiec
authors.forename: Magdalena
authors.initials: M
authors.lastname: Spólnicka
authors.forename: Paweł
authors.initials: P
authors.lastname: Krajewski
authors.forename: Tomasz
authors.initials: T
authors.lastname: Bednarczuk
authors.forename: Rafał
authors.initials: R
authors.lastname: Płoski
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D004270:DNA, Circular / Q000097:blood*; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics*; D019672:Genes, T-Cell Receptor / Q000235:genetics*; D006111:Graves Disease / Q000097:blood* / Q000235:genetics / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D004270:DNA, Circular