Correlation of serum IL-6, TNF-α levels and disease activity in patients with ankylosing spondylitis.

Objective: The aim of this study was to investigate the serum interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α) levels in patients with ankylosing spondylitis (AS), and the correlation between serum levels and disease activity.
Patients and Methods: ELISA was used to detect the serum TNF-α and IL-6 levels of AS patients (n=40) and normal controls (n=40) who were hospitalized or outpatient-diagnosed from June 2021 to May 2023. C-reactive protein (CRP) was detected by immune-enhanced turbidimetry. The erythrocyte sedimentation rate was determined by Wei's manual method. The correlation was analyzed by Pearson's correlation analysis.
Results: The levels of TNF-α and IL-6 in the AS group were significantly higher than those in the control group, and the levels of TNF-α and IL-6 in AS patients in the active phase were higher than those in the stable phase (p<0.05). CRP level was positively correlated with TNF-α, and IL-6 (r=0.02886 and 0.0273, p<0.05). Erythrocyte sedimentation rate (ESR) level was also positively correlated with TNF-α, and IL-6 (r=0.07568 and 0.0613, p<0.05).
Conclusions: Serum TNF-α and IL-6 levels are correlated with AS disease activity, suggesting that they may be involved in the inflammatory response of AS.