Serum sclerostin as a biomarker of disease activity in ankylosing spondylitis in correlation with radiographic imaging

Abstract
Background
The wingless signaling pathway of bone development is inhibited by sclerostin, which may contribute to the etiology of ankylosing spondylitis.

Aim
The study aimed to evaluate serum sclerostin levels in ankylosing spondylitis patients and investigate how it correlated with radiographic damage using the Spondylo-arthritis Research Consortium of Canada index (SPARCC), disease activity, and functional impairment.

Results
This cross-sectional case–control study revealed a significantly lower mean serum sclerostin (11.28 ng/ml) in AS patients compared with controls (101.25 ng/ml). Serum sclerostin levels showed a significant negative correlation with each of Bath Ankylosing Spondylitis Metrology Index (BASMI) (p = 0.043), sacroiliac joints SPARCC, spine SPARCC, and overall SPARCC scores (p = 0.012, p = 0.036, and p = 0.007). The detection of AS, serum sclerostin levels ≤ 20 ng/ml showed 100% sensitivity and specificity.

Conclusion
Serum sclerostin had good discriminating power between ankylosing spondylitis cases and healthy control individuals and was correlated with subclinical activity status on magnetic resonance imaging.