FRI0600 DIAGNOSTIC VALUE OF SERUM CONNECTIVE TISSUE GROWTH FACTOR IN RHEUMATOID ARTHRITIS
Authors: R. Jiaqi, J. Zhao, L. Sun, Z. MA, X. Wang
Journal: Annals of the Rheumatic Diseases (2020)

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&lt;0.0001). The mean titer of serum CTGF in RA was also significantly higher than those in other rheumatic diseases and healthy controls (p&lt;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&lt;0.001), rheumatoid factor (p&lt;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. References: [1] Ramazani Y, et al. (2018) Connective tissue growth factor (CTGF) from basics to clinics. Matrix Biol 68-69:44-66. [2] Nozawa K, F et al. (2009) Connective tissue growth factor promotes articular damage by increased osteoclastogenesis in patients with rheumatoid arthritis. Arthritis research &amp; therapy 11 (6):R174. [3] Yang X, et al. (2017) Serum connective tissue growth factor is a highly discriminatory biomarker for the diagnosis of rheumatoid arthritis. Arthritis research &amp; therapy 19 (1):257. [4] Wei JL, et al. (2018) Role of ADAMTS-12 in Protecting Against Inflammatory Arthritis in Mice By Interacting With and Inactivating Proinflammatory Connective Tissue Growth Factor. Arthritis &amp; rheumatology (Hoboken, NJ) 70 (11):1745-1756. [5] Tang X, et al. (2018) Connective tissue growth factor contributes to joint homeostasis and osteoarthritis severity by controlling the matrix sequestration and activation of latent TGFbeta. Ann Rheum Dis 77 (9):1372-1380. Fig 1. Distribution of serum CTGF in RA, other rheumatic diseases and healthy control. Serum sample were from 180 patients with rheumatoid arthritis (RA), 168 patients with other rheumatic diseases and 64 healthy individuals (HC). Levels of serum CTGF were measured by CTGF ELISA kit. The cut-off value was 263.30 pg/mL (black horizontal dotted line); ***p &lt;0.001 Table 1. Demographic, clinical and laboratory features of total RA patients and grouped with serum CTGF. Abbreviations: RA=rheumatoid arthritis; SJC=swollen joint count; TJC=tender joint count; ESR=erythrocyte sedimentation rate; CRP=C-reactive protein; DAS=disease activity score; CCP=cyclic citrullinated peptid; RF=rheumatoid factor. CTGF=connective tissue growth factor; ILD= interstitial lung disease Disclosure of Interests: None declared