title: Soluble triggering receptor expressed on myeloid cells-1 is a biomarker of anti-CCP-positive, early rheumatoid arthritis.
abstract: OBJECTIVE
  To assess serum soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) levels in disease-modifying antirheumatic drug (DMARD)-naïve early rheumatoid arthritis (ERA), to investigate the association of sTREM-1 levels with Disease Activity Score in 28 joints (DAS28) and seropositivity for anti-cyclic citrullinated peptide (CCP) antibody and to determine the predictive value of sTREM-1 with respect to clinical response to DMARD therapy.
  
  
  METHODS
  Twenty-two consecutive patients with DMARD-naïve ERA were prospectively evaluated for serum sTREM-1 by means of ELISA at diagnosis and at the following clinic visit after prednisone and/or DMARD has been administered, and related to DAS28 and serum level of anti-CCP antibody. We compared the sTREM-1 level to that of 31 patients with established RA as well as to 24 controls.
  
  
  RESULTS
  Serum sTREM-1 level was significantly higher in the DMARD-naïve ERA group (212.9 ± 388.9 ρg/mL) compared to established RA group (1478.0 ± 280.0 ρg/mL, P = 0.001) and normal control (34.4 ± 7.4 ρg/mL, P < 0.001). In the ERA group, elevated basal sTREM-1 level correlated with higher DAS28-CRP score (P = 0.001, HR 3.23, 95% CI 1.4-8.12), DAS28-ESR (P = 0.04, HR 2.34 95% CI 0.1-8.12), as well as predicted higher DAS28 score at the following encounter after DMARD treatment was administered (P = 0.001, HR 3.2 95% CI 1.1-7.2). Higher serum level of sTREM-1 correlated with higher titres of anti-CCP antibody (P < 0.001).
  
  
  CONCLUSIONS
  Our results suggest that serum sTREM-1 may provide a novel biomarker for DMARD-naïve ERA as well as for seropositivity for anti-CCP antibody and RA activity.
authors.affiliation: Rheumatology Unit, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.|Laboratory of Inflammation Research, Felsenstein Medical Research Center, Petach Tikva, Israel.|Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Yair
authors.initials: Y
authors.lastname: Molad
authors.affiliation: Department of Internal Medicine H, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.
authors.forename: Shachaf
authors.initials: S
authors.lastname: Ofer-Shiber
authors.affiliation: Rheumatology Unit, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.
authors.forename: Elisheva
authors.initials: E
authors.lastname: Pokroy-Shapira
authors.affiliation: Rheumatology Unit, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.
authors.forename: Shirly
authors.initials: S
authors.lastname: Oren
authors.affiliation: Rheumatology Unit, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.
authors.forename: Hagit
authors.initials: H
authors.lastname: Shay-Aharoni
authors.affiliation: Laboratory of Clinical Immunology, Rabin Medical Center, Beilinson Hospital, Petach Tikva, Israel.
authors.forename: Ilan
authors.initials: I
authors.lastname: Babai
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy; D001323:Autoantibodies / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D011446:Prospective Studies; D011971:Receptors, Immunologic / Q000378:metabolism*; D013582:Synovial Fluid / Q000378:metabolism; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents; D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; D011971:Receptors, Immunologic; C473366:TREML1 protein, human; C487763:cyclic citrullinated peptide
keywords: Anti-cyclic citrullinated peptide antibody (anti-CCP); biomarker; disease activity; rheumatoid arthritis; triggering receptor expressed on myeloid cells-1 (TREM-1)