Fetuin‐A and interleukin‐18 levels in ankylosing spondylitis

Aim: Interleukin‐18 (IL‐18) and fetuin‐A have been implicated in atherosclerosis. Preliminary evidence suggests that ankylosing spondylitis (AS) is associated with an increased risk of atherosclerosis. The aim of the present study was to investigate possible abnormalities in IL‐18 and fetuin‐A levels in AS. Methods: Subjects without established cardiovascular (CV) risk factors were studied. Fasting glucose, serum lipids, high sensitive C‐reactive protein (hsCRP), erythrocyte sedimentation rate, IL‐18 and fetuin‐A were assessed. Patients were also evaluated with the Bath Ankylosing Spondylitis Metrology Index, Bath Ankylosing Spondylitis Functional Index, and the Bath Ankylosing Spondylitis Disease Activity Index. Results: Fourty‐five patients with AS (37.4 ± 9.7 years; 35M/10F) and 29 controls (35.5 ± 11.1 years; 21M/8F) were studied. Fetuin‐A levels were significantly higher in AS patients compared to controls (1023.5 ± 171.6 vs. 856.9 ± 207.9 μg/mL, P < 0.001). IL‐18 levels were also higher in the AS group but the difference was not significant (184 ± 186 vs. 140 ± 115, P = 0.1). Significant but weak correlations were found between fetuin‐A, IL‐18, hsCRP, low density lipoprotein cholesterol, and triglyceride levels (P < 0.05; r = 0.4, 0.3, 0.2, and 0.3 respectively). Comparison of subjects with respect to the treatment type, disease activity and history of peripheral arthritis yielded no difference regarding fetuin‐A and IL‐18 between groups. Conclusion: Fetuin‐A and IL‐18 levels seem to be increased in AS patients regardless of disease activity and treatment type.