title: Serum levels of transforming growth factor-β1 (TGF-β1) in patients with systemic lupus erythematosus and Hashimoto's thyroiditis.
abstract: BACKGROUND
  Transforming growth factor-β1 (TGF-β1) exerts broad anti-inflammatory and immunosuppressive effects and plays a key role in self-tolerance. Complete knockout of TGF-β1 in mice results in autoimmunity and multi-organ inflammatory syndrome. The aim of the present study was to determine TGF-β1 serum levels in healthy individuals and in patients with typical systemic or organ-specific autoimmune disorders such as systemic lupus erythematosus (SLE) and Hashimoto's thyroiditis (HT) in an attempt to elucidate the importance of TGF-β1 in human autoimmunity.
  
  
  METHODS
  Serum concentrations of TGF-β1 were determined using an enzyme-linked immunosorbent assay in a group of 53 patients with SLE (87% women) and 123 with HT (95% women). Results were compared with those from 66 healthy controls (HC; 80% women).
  
  
  RESULTS
  Significantly lower levels of serum TGF-β1 were found in patients with SLE and HT than those found in HC (mean ± SD: SLE: 8.7 ± 2.5 ng/mL; HT: 18.74 ± 8.2 ng/mL; HC: 33.01 ± 2.4.8 ng/mL; SLE versus HC: p<0.001; HT versus HC: p<0.001). Also, serum levels of TGF-β1 were significantly lower in patients with SLE compared to patients with HT (p<0.001). The serum levels TGF-β1 were significantly higher in men than in women in the HC group (63.4 ± 28.1 ng/mL versus 26.6 ± 17.5 ng/mL, P<0.001), but were similar for men and women in both patients groups (p>0.05).
  
  
  CONCLUSIONS
  Our data demonstrate that altered TGF-β1 levels are associated with the presence of autoimmune disorders, and that TGF-β1 concentrations seem to be more profoundly depressed in systemic autoimmune diseases than in autoimmune thyroid disorders. Autoimmunity may have been triggered as a result of a decreased immunosuppressive effect induced by depressed TGF-β1 levels in patients with SLE and Hashimoto's thyroiditis.
authors.affiliation: Department of Health Care, Medical Faculty, Trakia University, St. Zagora 6003, Bulgaria. imanolova@mf.uni-sz.bg
authors.forename: Irena
authors.initials: I
authors.lastname: Manolova
authors.forename: Julieta
authors.initials: J
authors.lastname: Gerenova
authors.forename: Mariana
authors.initials: M
authors.lastname: Ivanova
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D016022:Case-Control Studies; D003710:Demography; D005260:Female; D050031:Hashimoto Disease / Q000097:blood*; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D008297:Male; D051379:Mice; D008875:Middle Aged; D015999:Multivariate Analysis; D053773:Transforming Growth Factor beta1 / Q000097:blood*; D055815:Young Adult
chemical_list: C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1
keywords: Hashimoto's thyroiditis; autoimmunity; systemic lupus erythematosus; transforming growth factor-β1