Baseline angiopoietin-2 / angiopoietin-1 (Ang2 / Ang1) ratio is correlated with the synovial vascularity measured 1 month later in rheumatoid arthritis

-Background Synovial angiogenesis is a component of rheumatoid pannus and considered to be an important early step in the pathogenesis of rheumatoid arthritis (RA). Objectives The aim of this study was to evaluate the serum levels of angiopoietin-1 (Ang1), angiopoietin-2 (Ang2), as well as the significance of the Ang2/Ang1 ratio in RA in relation to the joints’ blood flow signals and RA activity parameters. In addition, we studied their relevance in predicting the state of angiogenesis. Patients and methods This study was carried out on 65 consecutive very early RA patients. Power Doppler ultrasonography was performed in a total of 10 joints. The blood flow signals of each joint were scored on a three-grade scaling system. The total of the scores of the 10 joints was defined as the total signal score (TSS). On the same day, serum variables including vascular endothelial growth factor (VEGF), Ang1 and Ang2 levels, and clinical disease activity were evaluated. All the parameters measured were reassessed after 1 month. Results Serum VEGF, Ang2 levels, and Ang2/Ang1 ratio were significantly correlated with C-reactive protein, DAS28-CRP, and TSS at baseline and after 1 month. Moreover, significant correlations were observed between serum VEGF and Ang2 levels and Ang2/Ang1 ratio both at baseline and 1 month later. Interestingly, baseline serum VEGF level and Ang2/Ang1 ratio were significantly correlated with TSS after 1 month. Conclusion Serum concentrations of VEGF and Ang2 as well as Ang2/Ang1 ratio were correlated with parameters of inflammation in early RA. Elevated serum VEGF and Ang2/Ang1 ratio (in favor of Ang2) could reflect a phase of vigorous angiogenesis.