FRI0600 DIAGNOSTIC VALUE OF SERUM CONNECTIVE TISSUE GROWTH FACTOR IN RHEUMATOID ARTHRITIS

Abstract

Background:Many autoantibodies are found in the serum of rheumatoid arthritis (RA) patients, including RF, ACPA and so on, which are essential for the disease diagnosis and prognosis judgment. However, 20-30% of patients are still seronegative, so more investigations are needed to find new biomarkers in RA.Objectives:To investigate the prevalence of serum connective tissue growth factor (CTGF) and the association with the clinical features in RA patients.Methods:Serum samples were obtained from 180 patients with RA, 168 patients with other rheumatic diseases, including 43 systemic lupus erythematosus (SLE), 34 osteoarthritis (OA), 17 primary Sjögren’s syndrome (pSS), 20 ankylosing spondylitis (AS), 23 psoriatic arthritis (PsA), 6 reactive arthritis (ReA), 20 systemic sclerosis (SSc), and 5 systemic vasculitis (SV), and 64 healthy individuals in Peking University Third Hospital. The clinical and laboratory data of patients with RA were collected. Levels of CTGF in serum were measured by ELISA. The cut-off value of CTGF was determined by 95 percent of the concentration of the healthy controls. Statistical analyses were performed using the SPSS 24.0 software. Associations between CTGF and the clinical features of RA were evaluated.Results:The prevalence of serum CTGF among RA patients (33.89%) was significantly higher than those of SLE (9.3%), OA (0%), AS (0%), pSS (0%), PsA (0%), ReA (0%), SSc(5%), SV(0%) and healthy controls (4.69%) (p<0.0001). The mean titer of serum CTGF in RA was also significantly higher than those in other rheumatic diseases and healthy controls (p<0.001). At the cutoff value of 264.30 pg/ml, the sensitivity, specificity, positive predictive value and negative predictive value of serum CTGF for RA were 33.89%, 96.55%, 88.41% and 55.45% respectively. Anti-cyclic citrullinated peptide (CCP) antibody (p<0.001), rheumatoid factor (p<0.001), IgG (p=0.025) and IgM (p=0.004) in CTGF-positive patients were higher than those in CTGF-negative patients. Besides, more patients with interstitial lung disease (ILD) were found in CTGF-positive RA.Conclusion:Serum CTGF, as a novel biomarker, has certain diagnostic value for RA. Further studies are necessary to get more knowledge for the diagnostic performance of CTGF in RA.