Serum VEGF levels may have a role in the assessment of treatment response and disease activity during TNFi therapy in patients with axSpA

ABSTRACT Objectives To evaluate the relationship between serum biomarkers (VEGF, MMP-3, leptin) and disease activity and the changes in those biomarker levels during tumour necrosis factor inhibitor (TNFi) treatment in patients with axial spondyloarthritis (axSpA). Methods Patients with axSpA initiating their first TNFi and had serum samples at baseline and the 6th month of therapy were included, and the relation between these biomarkers and disease activity, function parameters were analysed. Results A total of 74 axSpA patients (mean age SD 48.7 12.8 years, 54.1% male) were included. Disease activity parameters (BASDAI, ASDAS, and BASFI) and CRP were significantly decreased at the 6th month of TNFi therapy (all p 0.001). The correlation between biomarker levels and disease activity was evaluated, and only serum MMP-3 levels were found to be associated with baseline ASDAS (p = 0.02). Serum VEGF level decreased compared to the baseline at the 6th month (p 0.001), however, serum leptin and MMP-3 levels were not affected by TNFi (p = 0.50). Serum VEGF levels were substantially correlated with gender, hip involvement, delay in diagnosis, and disease activity in the longitudinal analysis. Conclusion In patients with axSpA, TNFi therapy significantly reduces serum VEGF levels and effectively reduces disease activity. VEGF has the potential to function as a dynamic biomarker that reflects the characteristics of the disease and the response to treatment.