title: High redox thioredoxin but low thioredoxin reductase activities in the serum of patients with rheumatoid arthritis.
abstract: BACKGROUND
  Thioredoxin (Trx)/thioredoxin reductase (TrxR) is a redox-active system induced by oxidative stress. We investigated its status as a function of RA disease activity.
  
  
  METHODS
  64 consecutive RA patients and 27 healthy subjects were enrolled in the study. Serum Trx protein levels were evaluated using an immunoassay and immunoblot, while redox Trx and TrxR activities and oxidative stress markers (carbonyl groups, thiols), were determined using spectrophotometric methods.
  
  
  RESULTS
  Redox Trx activity and Trx protein concentrations were significantly higher in RA patients than in controls (redox Trx activity: 37.7+/-22.6 versus 21.1+/-7.9 ng/mL, p<0.01; Trx protein: 25.5+/-12.0 versus 12.3+/-5.1 ng/mL, p<0.0001). Redox Trx activity correlated with the DAS score (r=0.45, p=0.004) and with the tender joint count (r=0.49, p=0.002) whereas there was no correlation with Trx protein concentrations. Immunoblot analysis showed that circulating Trx was partially aggregated. TrxR activity was lower in the serum of RA patients than in healthy subjects (197+/-70 versus 263+/-56 U/L, p=0.002). TrxR activity was correlated with the DAS score (r=0.53, p<0.001) and with the tender joint count (r=0.36, p<0.01). There were no correlations between oxidative stress marker levels and redox Trx activity, Trx protein concentrations or TrxR activity.
  
  
  CONCLUSIONS
  Redox Trx and TrxR activities correlated with the disease activity of RA patients consistent with the hypothesis that Trx/TrxR activities may contribute to disease activity in RA.
authors.affiliation: Department of Biochemistry A, Paris 5 University, Assistance Publique-Hôpitaux de Paris, Cochin Hospital, Paris, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Lemarechal
authors.forename: Yannick
authors.initials: Y
authors.lastname: Allanore
authors.forename: Camille
authors.initials: C
authors.lastname: Chenevier-Gobeaux
authors.forename: Ohvanesse G
authors.initials: OG
authors.lastname: Ekindjian
authors.forename: André
authors.initials: A
authors.lastname: Kahan
authors.forename: Didier
authors.initials: D
authors.lastname: Borderie
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000201:enzymology* / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000097:blood / Q000737:chemistry; D013880:Thioredoxin-Disulfide Reductase / Q000097:blood* / Q000378:metabolism; D013879:Thioredoxins / Q000097:blood* / Q000378:metabolism*
chemical_list: D013438:Sulfhydryl Compounds; D013879:Thioredoxins; D013880:Thioredoxin-Disulfide Reductase