Dickkopf-1 in ankylosing spondylitis: Review and meta-analysis.

Background Current findings regarding serum Dickkopf-1 (DKK-1) concentration in ankylosing spondylitis (AS) have proven inconsistent. This meta-analysis was performed to provide a better understanding of serum DKK-1 and AS. Methods Online electronic databases were used to retrieve all relevant articles published before November 2017. The pooled standardized mean difference (SMD) with 95% confidence interval (CI) was calculated by the random-effect model. Results 23 studies, containing 1348 AS patients and 909 healthy controls, were included in this meta-analysis. No significant difference in serum DKK-1 concentration was found between AS patients and healthy controls (pooled SMD = 0.488, 95%CI = −0.176 to 1.152, p  = 0.150). Subgroup analyses suggested that serum DKK-1 in patients with increased C-reactive protein (CRP) (CRP > 10 mg/L) and high modified Stroke AS Spine Score (mSASSS) (mSASSS > 30) were significantly lower than healthy controls. Serum DKK-1 was, however, increased in patients with normal CRP (CRP   ≤ 10 mg/L). Conclusion Although serum DKK-1 concentration was not significantly different in AS vs. healthy controls, it may be used as a biomarker of inflammation and radiographic damage in AS. [ABSTRACT FROM AUTHOR]