Dickkopf-1 in ankylosing spondylitis: relation to spinal dysmobility and radiographic findings

ABSTRACT

Dickkopf-1 [DKK-1] is an inhibitory molecule that regulates Wnt pathway, which is critically important in osteoblastic new bone formation, therefore it may play a role in the process of new bone formation in Ankylosing Spondylitis [AS]. To measure serum level of DKK-1 in AS patients and study the relation between these levels with disease activity, spinal dysmobility and radiographic findings. Thirty AS patients as well as 20 healthy subjects as a control group were included in this study. DKK-1 serum levels were measured using ELISA technique, disease activity was assessed using Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] score, radiographic assessment by Bath Ankylosing Spondylitis Radiology Index-spine [BASRI-s] and modified Stoke Ankylosing Spondylitis Spinal Score [mSASSS]. DKK-1 was not correlated to ESR, CRP or BASDAI [p > 0.05] and was negatively correlated to BASRI-s and mSASSS [p < 0.001], though DKK-1 serum level was unexpectedly higher in patients versus control [p < 0.001]. On comparing HLA-B27 positive and HLA-B27 negative patients, there were a significant increase in BASRI-s and mSASSS and decrease in DKK-1 level in those with positive HLA-B27 [p < 0.05]. On comparing patients received anti TNF therapy and those not received anti TNF therapy, there was no significant difference in DKK-1 level [p > 0.05]. Our finding suggests dysfunction of DKK-1 in patient with AS