Background: Synovial angiogenesis and inflammation with articular damage are the main pathologic changes in rheumatoid arthritis (RA). The implication of the chemokine CXCL12 in disorders of the immune system had been identified. CXCL12 is involved in the inflammatory process by triggering leukocyte recruitment and neovascularization. Therefore, this research aims to investigate the serum CXCL12 level in RA patients and define how it correlates with disease activity.

Patients and methods: This study comprised 44 RA patients as well as 44 matched controls. Health assessment questionnaire disability index (HAQ- DI) as well as disease activity score (DAS-28) were determined. CXCL12 level was assessed in the sera of participants.

Results: Serum CXCL12 concentration was significantly elevated in RA patients (1475.16 ± 480.78 pg/ml) compared to controls (484.6 ± 177.85 pg/ml; p<0.001). Significant relations were detected between CXCL12 with tender joint count (p<0.001), swollen joint count (p<0.001), morning stiffness duration (p<0.001), DAS-28 (p<0.001), HAQ-DI (p<0.001), rheumatoid factor (RF) titer (p<0.001), anti-cyclic-citrullinated peptide(anti-CCP) level (p=0.001), C-reactive protein (p<0.001), and erythrocyte sedimentation rate (p<0.001). Serum CXCL12 significantly discriminated RA patients from healthy subjects (AUC = 0.99; p<0.001), as well as active RA cases from those in remission (AUC = 0.96; p<0.001).

Conclusion: This study indicated the fundamental utility of serum CXCL12 in RA activity monitoring.

Keywords: Rheumatoid arthritis; CXCL12; disease activity.