Can disease activity be detected with serum biomarkers in ankylosing spondylitis?

Aims: The inflammation in Ankylosing Spondylitis (AS) patients is crucial regarding disease activity and progression. This study aims to evaluate the diagnostic significance of inflammatory markers in assessing disease activity in AS. Methods: Seventy-six patients who met the criteria were assessed between January 2024 and June 2024. Inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic inflammatory index (SII), and uric acid-to-HDL cholesterol ratio (UHR) were analyzed. Patients were divided into two groups as active and inactive AS according to the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score. ROC analysis was performed to investigate the diagnostic role of UHR and SII in indicating active disease. Results: In the active disease group, parameters indicating inflammation, such as NLR (p=0.003), SII (p=0.001), and UHR (p=0.008), were found to be significantly elevated statistically. Positive statistically significant correlations were observed in correlation analysis between disease activity score and SII (r=0.36, p=0.006) and UHR (r=0.46, p=0.0001). ROC analysis revealed that UHR and SII have a high diagnostic role in indicating active disease. Conclusion: NLR, SII, and UHR are considered to have a diagnostic role in indicating inflammation and active disease in AS patients.