SDF-1 and CXCR4 in Synovium Are Associated with Disease Activity and Bone and Joint Destruction in Patients with Rheumatoid Arthritis Treated with Golimumab

Objectives: The aim of this study was to determine whether the levels of stromal cell-derived factor (SDF)-1 and its receptor C-X-C chemokine receptor 4 (CXCR4) in synovium were correlated with clinical outcome and bone and joint destruction in rheumatoid arthritis (RA) patients being treated with golimumab.

Methods: Synovial tissues were obtained from 15 golimumab-treated patients and were assessed for SDF-1 and CXCR4 using a new immunohistological scoring system (IH score). The IH score was used to assess correlations between synovial SDF-1 or CXCR4 and the disease activity score (DAS28 CRP), Rooney score, tumor necrosis factor alpha, interleukin-6 (IL-6), CD4, CD20, CD68 and the Assessment of RA by Scoring of Large-Joint Destruction and Healing in Radiographic Imaging (ARASHI) score. Receiver-operating characteristic (ROC) curves were used to predict ARASHI scores from the CXCR4 IH scores.

Results: SDF-1 strongly correlated with the DAS28 CRP and serum IL-6. CXCR4 correlated with synovial CD4 and the ARASHI score. ROC analysis of CXCR4 and ARASHI scores >10 indicated a cutoff of 12 points on the IH score for predicting joint destruction during treatment.

Conclusions: Synovial SDF-1 correlated with disease activity, and its receptor CXCR4 was related to joint destruction in RA patients treated with golimumab.