title: GlycA, a novel marker of inflammation, is elevated in systemic lupus erythematosus.
abstract: BACKGROUND
  GlycA is a novel marker of systemic inflammation detected by nuclear magnetic resonance (NMR) spectroscopy. In the general population, GlycA is correlated with inflammatory markers such as C-reactive protein (CRP) and associated with coronary heart disease and diabetes. The utility of GlycA in patients with systemic lupus erythematosus (SLE) has not been defined. Therefore, we tested the hypothesis that GlycA concentrations are elevated in patients with SLE and associated with other markers of inflammation and coronary atherosclerosis.
  
  
  METHODS
  We compared concentrations of GlycA, detected by NMR, in 116 patients with SLE and 84 control subjects frequency-matched for age, sex, and race. SLE disease activity index (SLEDAI) and the SLE Collaborating Clinics damage index (SLICC) were calculated. Acute phase reactants, a panel of cytokines, and a lipid panel were measured. Electron beam computer tomography (EBCT) was used to quantify coronary artery calcification, a measure of coronary artery atherosclerosis.
  
  
  RESULTS
  Patients with SLE had higher concentrations of GlycA (398 (350-445)) than control subjects (339 (299-391)) µmol/L, p < 0.001. In patients with SLE, concentrations of GlycA were significantly associated with sedimentation rate (rho = 0.43), C-reactive protein (rho = 0.59), e-selectin (rho = 0.28), intracellular adhesion molecule-1 (rho = 0.30), triglycerides (rho = 0.45), all p < 0.0023 to account for multiple comparisons, but not with creatinine, SLEDAI, SLICC, or coronary calcium scores.
  
  
  CONCLUSIONS
  Concentrations of GlycA are higher in patients with SLE than control subjects and associated with markers of inflammation but not with SLE disease activity or chronicity scores or coronary artery calcification.
authors.affiliation: Department of Medicine, Vanderbilt University, Nashville, USA c.chung@vanderbilt.edu.
authors.forename: C P
authors.initials: CP
authors.lastname: Chung
authors.affiliation: Department of Medicine, Vanderbilt University, Nashville, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Ormseth
authors.affiliation: LabCorp, Raleigh, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Connelly
authors.affiliation: Department of Medicine, Vanderbilt University, Nashville, USA.
authors.forename: A
authors.initials: A
authors.lastname: Oeser
authors.affiliation: Department of Medicine, Vanderbilt University, Nashville, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Solus
authors.affiliation: LabCorp, Raleigh, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Otvos
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Raggi
authors.affiliation: Department of Medicine, Vanderbilt University, Nashville, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Stein
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000737:chemistry*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008055:Lipids / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D018836:Inflammation Mediators; D008055:Lipids
keywords: GlycA; Systemic lupus erythematosus; inflammation