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-alpha (TNF-alpha). Our study included 69 patients with RA and 48 age- and sex-matched healthy controls. Serum concentrations of TNF-alpha 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 or =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-alpha and it may be a novel biomarker for assessing inflammatory activity in patients with RA.