title: Relationship between rheumatoid arthritis activity and antithyroid antibodies.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is known to be associated with a higher prevalence of antithyroid antibodies and autoimmune thyroid disease, but there have been few studies regarding the correlations between the presence of these antibodies and RA activity.
  
  
  OBJECTIVE
  The aim of this study was to analyze the relationship between antithyroid antibody titers and selected parameters of RA activity.
  
  
  METHODS
  A total of 75 consecutive hospitalized patients with RA were enrolled into the study. Levels of antithyroid peroxidase antibodies (aTPO), antithyroglobulin antibodies (aTG), and antithyrotropin receptor antibodies (aTSH-R) were measured. The analysis of disease activity was based on the disease activity score with 28-joint count (DAS28), duration of morning stiffness, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) and hemoglobin levels.
  
  
  RESULTS
  Antithyroid antibodies were present in 13.3% of the patients (n = 10), aTPO in 9.3% (n = 7), aTG in 8% (n = 6), and aTPO and aTG in 4% (n = 3); aTSH-R was not detected in any of the patients. Significant positive correlations (P <0.05) were observed between aTPO and DAS28 (r = 0.35, P = 0.002), aTG and ESR (r = 0.25, P = 0.02), and aTG and CRP (r = 0.23, P = 0.04). There were significant differences in the mean DAS28 between the aTPO‑positive and aTPO‑negative groups (5.35; 95% confidence interval [CI], 4.39-6.3 vs. 4.12, respectively; 95% Cl, 3.81-4.43; P = 0.017) and between the aTG-positive and aTG-negative groups (5.65; 95% Cl: 4.64-6.67 vs. 4.11; 95% Cl: 3.81-4.41; P = 0.005; respectively).
  
  
  CONCLUSIONS
  Our results suggest that RA activity may be associated with the presence of antithyroid antibodies. This finding could be useful in the clinical evaluation of RA patients.
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Koszarny
authors.forename: Maria
authors.initials: M
authors.lastname: Majdan
authors.forename: Dorota
authors.initials: D
authors.lastname: Suszek
authors.forename: Ewa
authors.initials: E
authors.lastname: Wielosz
authors.forename: Magdalena
authors.initials: M
authors.lastname: Dryglewska
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; C006606:anti-thyroglobulin; C056626:thyroid microsomal antibodies; D012217:Rheumatoid Factor