Significance of serum levels of angiopoietin-2 and its relationship to Doppler ultrasonographic findings in rheumatoid arthritis patients

Angiopoietin-2 (Ang-2) is connected to angiogenesis in synovial regions, but the significance of its levels in patients with rheumatoid arthritis (RA) is still unclear. To evaluate the significance of serum levels of Ang-2 in patients with RA. Also, to determine Ang-2 relationship to the findings of joints Doppler ultrasonographic findings. This study included 40 patients with RA, and 25 matched healthy controls. All patients were subjected to assessment of pain using visual analogue scale (VAS), assessment of personal activity using the Health Assessment Questionnaire (HAQ) score, and calculation of disease activity score (DAS 28). Laboratory assays of complete blood count (CBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) titre, and measurement of serum levels of Ang-2 by ELISA. Doppler ultrasonography (US) assessment for eight joints, with calculation of synovial thickness and total signal score (TSS), was done. Serum Ang-2 levels were significantly higher among patients (3191.3 ± 594.9 pg/ml) than controls (1771.7 ± 103.1 pg/ml) (p < 0.001). Serum Ang-2 levels were significantly correlated with ESR, CRP, DAS28, and duration of morning stiffness (p < 0.001, p < 0.001, p < 0.001, and p = 0.025, respectively). There was a significant correlation between serum Ang-2 levels and findings of US, regarding joint synovial thickness, and TSS (p < 0.001, for both). Patients with RA had significantly higher levels of serum Ang-2 versus controls. In those patients, serum Ang-2 levels were significantly correlated with disease activity markers (ESR, CRP), DAS28, and duration of morning stiffness. Moreover, these levels were significantly correlated with synovial thickness, and TSS. The role of Ang-2 in RA pathogenesis might open the door to the development of new therapeutic strategies, particularly which target angiogenesis.