Serum chitotriosidase and neopterin levels in patients with ankylosing spondylitis.

Background: The aim of this study was to assess the serum chitotriosidase (ChT) and neopterin levels in patients with ankylosing spondylitis (AS) and to evaluate whether serum ChT and neopterin levels are related to disease activity. Methods: A total of 86 patients with AS were included in the study. Patients were divided into two groups based on Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores: The active AS patients group included 40 patients who had a BASDAI score > 4. The inactive AS patients group included 46 patients who had a BASDAI score <4. We compared the serum level of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), ChT and neopterin between the two groups. Results: Active AS patients had significantly higher ESR, CRP, serum ChT and neopterin levels compared with the inactive AS patients group (p < 0.05). Positive correlations were found between serum ChT levels and ESR (r = 0.87, p = 0.005), and CRP levels (r = 0.86, p = 0.006). Also, there was a positive significant correlation between serum ChT levels and BASDAI scores (r = 0.67, p = 0.03). No correlation was found between serum neopterin levels and the BASDAI scores, ESR, and CRP levels (p > 0.05). Higher disease activity (BASDAI score > 4) was found to be associated with ChT (p = 0.012) in the multiple logistic regression analysis. Conclusion: The present study emphasized that serum ChT levels can be useful in the determination of the disease activity of AS patients.