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

Back groundDickkopf-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).Aim of the workTo measure serum level of DKK-1 in AS patients and study the relation between these levels with disease activity, spinal dysmobility and radiographic findings.Patients and methodsThirty 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).ResultsDKK-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).ConclusionOur finding suggests dysfunction of DKK-1 in patient with AS.