Serum Visfatin levels in Ankylosing Spondylitis: Correlation with Disease Activity

Background: Ankylosing spondylitis (AS) is a form of spondyloarthropathy (SPA) that is featured by sacroiliac joints (SIJ), axial skeleton, entheses and peripheral joints inflammation. Non-radiographic axial spondyloarthropathy or nr-axSPA is a common early sign of AS before developing radiographic sacroiliitis. Visfatin is an adipokine produced in fat tissue mainly, as well as in skeletal muscle, brain, and hepatocytes. Visfatin has been demonstrated to contribute to bone homeostasis and it can induce pro-inflammatory responses in different cell types. Objective: This study aimed to investigate serum visfatin level among AS, nr-axSPA patients and controls and to elucidate its possible relationship with disease activity. Patients and methods: This was a case-control study, which comprised 26 AS cases, 26 nr-axSPA cases and 27 healthy volunteers age-and sex-matched with the patient groups. ELISA was used in measuring visfatin concentration in the serum of studied subjects. Results: Serum visfatin level was significantly higher in AS and nr-axSPA cases groups in comparison with control group (p<0.001). There was positive correlation between visfatin with Bath AS Disease Activity Index (BASDI) (P= 0.032) and (P=0.001), and Bath AS Functional Index (BASFI) (p=0.004) and (p=0.001) in AS and nr-axSPA groups respectively. There were significant positive correlations between modified Stoke AS Spinal Score (mSASSS) and visfatin values in AS group (p<0.001). Visfatin concentrations didn't correlate with age, BMI, disease duration, ESR, CRP and ASDAS-CRP. Conclusion: Serum visfatin concentration was elevated in cases with AS and nr-axSPA, and it was accompanied by disease activity, functional impairment and radiographic damage.