Investigation of serum endocan level and its relationship with disease activity in patients with axial spondyloarthritis

Spondylarthritis (SpA) is a collective term describing a group of diseases with common clinical, radiological, laboratory and genetic features. It can be classified as predominantly peripheral SpA and predominantly axial SpA (axSpA) according to the involvement pattern. Unfortunately, there is no sensitive biomarker that can be used in clinical follow-up. Endocan is a molecule with proteoglycan structure. Studies have shown that endocan plays an important role in acute inflammation and in different stages of chronic inflammation. In this study, we aimed to investigate serum endocan levels and the correlation of these levels with clinical and laboratory parameters in patients diagnosed with axSpA. Thirty axSpA patients receiving biological therapy and diagnosed according to the "Assessment of Spondylarthritis International Society (ASAS)" classification criteria developed for axSpA and, 30 axSpA patients using non-steroidal anti-inflammatory drugs, and 30 healthy volunteers without known disease were included in the study. "Bath Ankylosing Spondylitis Disease Activity Index (BASDAI)", "Ankylosing Spondylitis Disease Activity Score (ASDAS)-CRP", "Bath Ankylosing Spondylitis Functional Index (BASFI)", AS quality of life index and "Bath Ankylosing Spondylitis Metrology Index (BASMI)" was used for the evaluation of patients. Demographic, clinical characteristics and laboratory data were recorded. Endocan levels in serum taken simultaneously were measured by enzyme linked immunosorbent assay (ELISA). There was no statistically significant difference in serum endocan levels between the spondylarthritis group and the control group (p: 0.084). There was also no statistically significant difference between the 3 groups in the subgroup analysis (p:0.175). There was a negative correlation between serum endocan level and erythrocyte sedimentation rate (ESR) (r: -0.32 and p: 0.010), and a positive correlation between serum endocan level and hemoglobin level (r: 0.335 and p: 0.009). A significant negative correlation was found between the duration of morning stiffness and serum endocan levels (r: -0.294 p: 0.022). In conclusion, in our study in which we investigated the roles of serum endocan levels in the diagnosis, follow-up and pathogenesis of axSpA, no statistically significant difference was found between the patient and control groups. Correlation was observed between serum endocan levels and some laboratory parameters. We believe that clinical studies with larger case numbers are needed to better understand the role of these molecules in the diagnosis, follow-up and pathogenesis of axSpA. Keywords: Axial spondylarthritis, ankylosing spondylitis, endocan.