BACKGROUND: To observe and demonstrate therapeutic effects and side effects of two selective COX-2 inhibitors, imrecoxib and celecoxib, on patients with axial spondyloarthritis (axSpA) and observe the correlation between imaging scores and serum DKK-1 levels.

MATERIAL AND METHODS: Sixty patients with axSpA were randomly assigned to receive 200 mg imrecoxib or 200 mg celecoxib twice daily. Fifty-one patients who completed follow-up were included in the study. At baseline, week 4, and week 12, the clinical parameters, inflammatory markers (ESR, CRP), and adverse reactions were recorded. Serum DKK-1 levels were investigated by enzyme-linked immunosorbent assay. Radiographic scores were calculated by sacroiliac joint SPARCC (Spondyloarthritis Research Consortium of Canada) score method at baseline serum DKK-1 levels and week 12.

RESULTS: Patients in the imrecoxib group (n=25) and patients in the celecoxib group (n=26) were improved at week 4. At week 12, all clinical parameters and inflammatory markers were improved in the two groups and the differences was not statistically significant. Serum DKK-1 levels were decreased and the differences were not statistically significant. Serum DKK-1 levels in patients in the imrecoxib group at baseline were negatively correlated with all study parameters, while those in the celecoxib group had correlations with BASFI (r=–0.048, p=0.027) and Schober test (r=0.437, p=0.048), without any correlation with other clinical parameters or inflammatory markers.

CONCLUSIONS: Patients experienced significant improvement in disease activity, functional parameters, and inflammatory markers when treated with selective COX-2 inhibitors for 12 weeks, and the efficacy of imrecoxib was not inferior to celecoxib. Selective COX-2 inhibitors imrecoxib and celecoxib had no obvious effects on serum DKK-1 levels.

Keywords: Cyclooxygenase 2 Inhibitors, Molecular Mechanisms of Pharmacological Action, Spondylitis, Ankylosing