title: Usefulness of serum leucine-rich alpha-2 glycoprotein as a disease activity biomarker in patients with rheumatoid arthritis.
abstract: Our study aimed to investigate whether serum leucine-rich alpha-2-glycoprotein (LRG) levels are elevated in patients with rheumatoid arthritis (RA). In addition, we assessed their correlation with disease activity parameters and pro-inflammatory cytokine, tumor necrosis factor-α (TNF-α). Our study included 69 patients with RA and 48 age- and sex-matched healthy controls. Serum concentrations of TNF-α and LRG were determined by enzyme-linked immunosorbent assay. Serum LRG concentrations were significantly elevated in patients with RA compared with those in healthy controls (30.8 ± 14.4 vs. 22.2 ± 6.1 ng/mL; P<0.001). In patients with RA, serum LRG levels were found to be correlated with disease activity score 28 (DAS28), erythrocyte sedimentation rate, and C-reactive protein levels (γ=0.671; γ=0.612; and γ=0.601, P<0.001, respectively), but not with serum TNF-α levels. Serum LRG levels in patients with an active disease status (DAS28≥2.6) were significantly higher than those in remission (DAS28<2.6) (36.45 ± 14.36 vs. 24.63 ± 8.81 ng/mL; P<0.001). Our findings suggest that serum LRG could contribute to the inflammatory process independent of TNF-α and it may be a novel biomarker for assessing inflammatory activity in patients with RA.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: You Jung
authors.identifier: 0000-0001-6107-9523
authors.initials: YJ
authors.lastname: Ha
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Busan Medical Center, Busan, Korea.
authors.forename: Eun-Jin
authors.initials: EJ
authors.lastname: Kang
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Soo-Kon
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong-Beom
authors.identifier: 0000-0003-4698-8620
authors.initials: YB
authors.lastname: Park
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Jung-Soo
authors.identifier: 0000-0001-8651-5125
authors.initials: JS
authors.lastname: Song
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea.
authors.forename: Sang Tae
authors.identifier: 0000-0002-2074-1733
authors.initials: ST
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012720:Severity of Illness Index; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D006023:Glycoproteins; C015246:LRG1 protein, human; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein
keywords: Arthritis, Rheumatoid; Disease Activity; Leucine-Rich Alpha-2-Glycoprotein; Tumor Necrosis Factor-alpha