To observe the therapeutic and side effects of the selective COX-2 inhibitor imrecoxib and celecoxib in patients with axial spondyloarthritis (ax-SpA), and explore the correlation with sacroiliac joint score and serum DKK1.

A total of 60 cases of axial spondyloarthritis (SpA) patients in the Rheumatism Immunity Branch of the First Affiliated Hospital of Zhengzhou University were included in the study. Patients were randomly assigned to receive 200 mg imrecoxib or 200 mg celecoxib twice daily. At the baseline, week 4 and week 12, the clinical parameters [Bath AS diseaseactivity index (BASDAI) and Bath AS functional index (BASFI), patients global assessment, tragus-to-wall distance, lumbar side flexion, Schober test, finger to floor distance, inter-malleoar distance], inflammatory markers erythrocyte sedimentation rate (ESR), C reactive protein(CRP) and adverse reactions were recorded. Serum levels of DKK-1 and SPARCC scores of sacroiliac joint were investigated at baseline and week 12.

Fifty-one patients were included in the analysis of clinical efficacy and safety at last. Patients of the imrecoxib group and the celecoxib group were improved in the following aspects at week 4: BASDAI (F=1.69), BASFI (F=0.43), patient global asses-sment (F= 12.51), tragus-to-wall (F=0.10), lumbar side flexion (F=0.23), Schober test (F=0.54), front distance (F=2.58), inter-malleoar distance (F=0.25) and ESR (F=0.65) (P<0.05), and the difference was not statistically significant com-pared with baseline between the two groups (P>0.05). At week 12, all clinical parameters and inflammatory markers were improved in the two group (P<0.05) and the difference was not significant between the 2 groups (P> 0.05). The difference of adverse drug reactions in the two groups was not statistically signifi-cant (P>0.05). The difference of radiographic score (SPARCC score) in patients of imrecoxib and celecoxib group from baseline to 12 weeks was not significant (t=1.967, P=0.064). The serum levels of DKK-1 was decreased and the difference was not statistically significant (t=1.815, P=0.085). Serum levels of DKK-1 in patients of the imrecoxib group at baseline was negatively correlated with all aspects. Serum levels of DKK-1 in the celecoxib group at baseline were correlated with BASFI (r=-0.048, P=0.027) and Schober test (r=0.437, P=0.048), but not correlated with other clinical parameters or inflammatory markers.

Patients with ax-SpA can have 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 is not inferior to celecoxib. Imrecoxib and celecoxib has no obvious effect on the serum level of DKK-1.

Axial spondyloarthritis; Cyclooxygenase-2; Molecular mechanisms of pharmaclogical action