ABSTRACT
BACKGROUND: The incidence of ankylosing spondylitis (AS) presents a trend of rising year by year, accompanied by a higher disability. Therefore, fully understanding the related factors to the development of AS is of great significance to develop a rational treatment scheme.OBJECTIVE: To evaluate the expression levels of Dickkopf-1 and sclerostin in Wnt signaling pathway as well as vascular endothelial growth factor A (VEGF-A) in the AS patients, and to evaluate their correlation with AS progression.METHODS: AS patients and healthy volunteers were recruited, and their baseline data and medical history were collected. The expression levels of Dickkopf-1, sclerostin, VEGF-A and C-reactive protein in the peripheral blood were detected; the AS progression was evaluated by Bath AS Disease Activity Index and Bath AS Functional Index; the imaging performance was assessed by modified Stroke AS Spine Score; the correlation of Dickkopf-1, sclerostin and VEGF-A with AS progression, imaging performance and inflammatory reaction was analyzed by Spearman's rank correlation analysis and multiple linear regression analysis.RESULTS AND CONCLUSION: No significant differences were found in the expression levels of Dickkopf-1, sclerostin and VEGF-A between two groups (P > 0.05). The AS patients without syndesmophyte and with higher erythrocyte sedimentation rate and C-reactive protein level appeared with an significant increase in the Dickkopf-1 level (P < 0.05),which was significantly related to sclerostin level (r=0.592, P=0.000). The As patients with the history of smoking,increase in erythrocyte sedimentation rate and C-reactive protein, as well as higher Bath AS Disease Activity Index and Bath AS Functional Index presented with a higher level of VEGF-A. Multiple linear regression analysis showed that erythrocyte sedimentation rate, C-reactive protein, syndesmophyte and sclerostin level were the independent factors affecting the Dickkopf-1 level (P ≤ 0.001); the history of smoking, erythrocyte sedimentation rate, and C-reactive protein were the independent factors affecting VEGF-A (P < 0.005). These results suggest that in AS patients, the Dickkopf-1 level is related to syndesmophyte and systemic inflammatory response, while the history of smoking affects VEGF-A level. Therefore, all above indicators can be used to evaluate osteophyte formation and bone mass loss.