title: The impact of inflammation on metabolomic profiles in patients with arthritis.
abstract: OBJECTIVE
  Inflammatory arthritis is associated with systemic manifestations including alterations in metabolism. We used nuclear magnetic resonance (NMR) spectroscopy-based metabolomics to assess metabolic fingerprints in serum from patients with established rheumatoid arthritis (RA) and those with early arthritis.
  
  
  METHODS
  Serum samples were collected from newly presenting patients with established RA who were naive for disease-modifying antirheumatic drugs, matched healthy controls, and 2 groups of patients with synovitis of ≤3 months' duration whose outcomes were determined at clinical followup. Serum metabolomic profiles were assessed using 1-dimensional (1) H-NMR spectroscopy. Discriminating metabolites were identified, and the relationships between metabolomic profiles and clinical variables including outcomes were examined.
  
  
  RESULTS
  The serum metabolic fingerprint in established RA was clearly distinct from that of healthy controls. In early arthritis, we were able to stratify the patients according to the level of current inflammation, with C-reactive protein correlating with metabolic differences in 2 separate groups (P < 0.001). Lactate and lipids were important discriminators of inflammatory burden in both early arthritis patient groups. The sensitivities and specificities of models to predict the development of either RA or persistent arthritis in patients with early arthritis were low.
  
  
  CONCLUSIONS
  The metabolic fingerprint reflects inflammatory disease activity in patients with synovitis, demonstrating that underlying inflammatory processes drive significant changes in metabolism that can be measured in the peripheral blood. The identification of metabolic alterations may provide insights into disease mechanisms operating in patients with inflammatory arthritis.
authors.affiliation: University of Birmingham, Birmingham, UK.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Young
authors.forename: Sabrina R
authors.initials: SR
authors.lastname: Kapoor
authors.forename: Mark R
authors.initials: MR
authors.lastname: Viant
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Byrne
authors.forename: Andrew
authors.initials: A
authors.lastname: Filer
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Buckley
authors.forename: George D
authors.initials: GD
authors.lastname: Kitas
authors.forename: Karim
authors.initials: K
authors.lastname: Raza
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D008875:Middle Aged; D019906:Nuclear Magnetic Resonance, Biomolecular; D013585:Synovitis / Q000097:blood* / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein