Background Monitoring of disease activity in axial spondyloarthritis is difficult due to lack of specific markers of inflammation. Conventional markers of inflammation namely ESR and CRP, seldom correlates with disease activity. To help in the early diagnosis and monitoring of axial spondyloarthritis, there has been a growing need for new biomarkers of disease activity.
Objectives To investigate the role of serum vascular endothelial growth factor (VEGF) and tumor necrosis factor alpha (TNF α) as markers of disease activity in patients with Axial Spondyloarthritis (axSpA).
Methods 40 patients with axSpA (28 with Ankylosing Spondylitis and 12 with non-radiological axSpA; mean age 29 years, mean duration 5 months) were included in this study. ESR, CRP, BASDAI/BASFI, serum TNF α and VEGF levels were assessed at baseline and after 12 weeks of therapy with either etanercept or NSAIDs (20 patients in each group). 20 healthy age and sex matched controls were also recruited for the study.
Results Patients with axSpA had higher levels of serum TNF α (mean 341pg/ml) and VEGF (mean 797pg/ml) when compared with healthy controls (mean 72.5 pg/ml, p<0.001 and mean 269 pg/ml, p<0.001). There was significant reduction in serum TNF α and VEGF levels after 12 weeks of treatment with etanercept (mean 161pg/ml, p<0.001 and mean 442 pg/ml, p<0.001 respectively) but not with NSAID (p=0.29, p=0.25). Both TNF α and VEGF had a positive correlation with BASDAI (r=0.57, p<0.01 and r=0.44, p<0.01) and BASFI (r=0.61, p<0.01 and r=0.33, p=0.03) at baseline. The levels of TNF α and VEGF showed no correlation with ESR and CRP (p=0.48, p=0.07 and p=0.21, p=0.06 respectively)at baseline. There was no correlation between BASDAI and levels of ESR, CRP (p=0.27 and p=0.49 respectively).
Conclusions Serum levels of TNF α and VEGF serve as better markers of disease activity when compared with ESR and CRP in axSpA. Significant reduction in VEGF levels with treatment makes it a potentially new therapeutic target in axSpA
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Disclosure of Interest None declared