AB0058 SERUM OXYTOCIN LEVELS IN PATIENTS WITH ANKYLOSING SPONDYLITIS AND NONRADIOGRAPHIC AXIAL SPONDYLARTHRITIS

Background Spondyloarthritis refers to a group of chronic inflammatory diseases with unknown etiologies that involve particularly sacroiliac joints and spine but may also affect the remaining joints and entheses and exhibit extra-articular involvement in some patients. Oxytocin is a peptide hormone released from hypothalamus and stored in pituitary gland. It has been known for a while that oxytocin has anti-inflammatory effects and can cause a reduction in TNF-alpha levels. Objectives The aim of this study was to investigate the serum levels of oxytocin and its potential association with disease activity, spinal mobility and some other laboratory parameters such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in patients with ankylosing spondylitis (AS) and non-radiographic axial spondylitis (nrAxSpA). Methods Seventy-one patients with nrAxSpA and 38 patients with AS who presented to the Outpatient Clinic of Physical Medicine and Rehabilitation of Dicle University Hospital between March 2017- October 2017 and 67 healthy control subjects were included in this study. All the subjects underwent a thorough physical examination. Disease activity was assessed by Bath Ankylosing Spondylitis Disease Activity Index, and spinal mobility by Bath Ankylosing Spondylitis Metrologic Index. Laboratory examinations included complete blood count, ESR, CRP, and oxytocin tests. Results There was no significant difference in serum levels of oxytocin among the three groups (p= 0.973). However, serum levels of oxytocin correlated negatively with both ESR (r= -0.359, p=0.027) and BASDAI scores (r= -0,448, p=0.005) in patients with AS. On the other hand, serum levels of oxytocin had a negative correlation only with ESR in the patients with nrAxSpA (r= -0.321 p= 0.009). Conclusion ESR is one of the parameters associated with disease activity in patients with inflammatory rheumatoid diseases. Serum levels of oxytocin correlating negatively with both ESR and BASDAI scores in patients with AS and only with ESR in patients with nrAxSpA suggests that low levels of oxytocin may be associated with increased disease activity. This study lays the foundation for further studies that may aim to investigate how addition of oxytocin to the treatment regimen impact on the disease activity in patients with AS who exhibit particularly low levels of oxytocin during active disease period. References [1] Clodi M, Vila G, Geyeregger R, Riedl M, Stulnig TM, Struck J, et al. Oxytocin alleviates the neuroendocrine and cytokine response to bacterial endotoxin in healthy men. Am J Physiol Endocrinol Metab. 2008; 295(3): E686-91 [2] Garrido-Urbani S, Deblon N, Poher AL, Caillon A, Ropraz P, Rohner-Jeanrenaud F, Altirriba J. Inhibitory role of oxytocin on TNFα expression assessed in vitro and in vivo. Diabetes Metab. 2018Jun;44(3):292-295. [3] Tong Li, Ping Wang, Stephani C. Wang, and Yu-Feng Wang. Approaches Mediating Oxytocin Regulation of the Immune System. Front Immunol. 2016; 7: 693. Disclosure of Interests None declared