AB1005 ASSOCIATION BETWEEN CHANGES IN SERUM ALKALINE PHOSPHATASE LEVELS AND RADIOGRAPHIC PROGRESSION IN ANKYLOSING SPONDYLITIS

Background The changes in bone metabolism may occur earlier than those that can be identified on radiography. Although studies have evaluated the inflammatory markers precede radiographic progression, no relationship between timing of and progression patients with AS. Objectives To determine serum alkaline phosphatase levels over time ankylosing spondylitis. Methods This retrospective study electronic medical records spondylitis January 2001 December 2018. Longitudinal data including were imputed by linear interpolation at 3-month intervals. Among for 8 years prior to measurement modified Stoke Ankylosing Spondylitis Spinal Score, level having highest beta coefficient Score was selected. Linear mixed models selected clinical variables, investigated. Results Overall, 1122 included, a mean follow-up period 8.20 (standard deviation: 2.85) years. Of series levels, previous 5 3 months showed (Figure 1). In model before significantly associated (β=0.021, 95% confidence interval: 0.017–0.025, p<. 001). Conclusion Serum measured approximately surrogate marker predicting spinal changes. Long-term prospective experimental > are required biomarker discovery or therapeutic research Figure 1. Beta coefficients ALP calculate (mSASSS). mSASSS had significant (0.020, CI 0.016–0.023) (asterisk). mSASSS, Score; ALP, phosphatase. REFERENCES: NIL. Acknowledgements: Disclosure Interests None Declared.