Serum Dickkopf-1 levels in patients with ankylosing spondylitis not affected by using tumor necrosis factor-α inhibitor / 中华风湿病学杂志

ABSTRACT

Objective Dickkopf-1 (DKK-1) is an antagonist of the Wnt signaling pathway of bone formation and it is the target gene of TNF.When DKK-1 is inhibited,osteoprotegerin (OPG) would increase,OPG can antagonize bone erosion caused by receptor activator of NF-κB ligand (RANKL).Detection the levelsof serum DKK-1,OPG,RANKL and TNF-α of patients with AS before and after applying TNF-α antagonist,the effects of anti-TNF-α treatment on signaling pathway of bone formation was explored.Methods Medical records and serum samples of 43 AS patients receiving TNF-α receptor-Ⅱ IgG Fc fusion protein for 12 weeks were collected and the levels of serum DKK-1,OPG,RANKL and TNF-α were detected by enzyme-linked immunosorbent assay.Paired t-test and Person's correlation analysis were used for data analysis.Results Disease activity indexes in AS patients with anti-TNF-α treatment,including VAS score,time of morning stiffness,BASDAI,BASFI,ESR and CRP,which were [(2.7±2.0) cm,(7±4) min,1.1±1.1,0.8±1.2,(10±9) mm/1 h and (16±26) mg/L] respectively,were reduced when compared with those before treatment,[(7.6±1.9) cm,(46±33) min,6.0±1.3,4.4±2.0,(39±29) mm/1 h and (76±43) mg/L] respectively,and the differences were statistically significant (P＜0.05).Serum levels of DKK-1,(3.3±1.5) μg/L vs (3.2±1.3) μg/L,OPG,(144±71) pg/ml vs (136±62) pg/ml,and RANKL,(71±37) pg/ml vs (68±30) pg/ml,were not changed (t=14.043,8.031,20.166,13.521,7.679,9.563,all P＞0.05).The levels of TNF-α increased from (1.9±1.3) pg/ml to (55.0±50.6) pg/ml (t=6.951,P＜0.05).There were no relations between DKK-1 and TNF-α,RANKUOPG,patient VAS,duration of morning stiffness,BASDAI,BASFI,ESR and CRP,allP＞0.05.Conclusion Clinical indicators are improved significantly by anti-TNF-α therapy; however,it should not be withdrawal suddenly.There is no relationship between serum levels of DKK-1 and level of inflammation in AS patients.