POS0932 REGULATION OF INTESTINAL FLORA RESTORES IMMUNE BALANCE IN PATIENTS WITH UNDIFFERENTIATED SPONDYLOARTHRITIS
Authors: T. Cheng, J. Guo, S. X. Zhang, Y. Zhang, Y. Li, X. Liu, X. F. Yin, X. Li
Journal: Annals of the Rheumatic Diseases (2021)

Background: Undifferentiated spondyloarthritis (USpA) is the most common subtype of the spondyloarthritides with a prevalence between 0.7% and 2.0% 1 . Inflammatory back pain, peripheral arthritis and less frequently enthesitis are the main clinical features of USpA 2 . Resently the role of dysregulated microbiome along with migration of T lymphocytes and other cells from gut to the joint (“gut-joint” axis) has been recognized 3 4 . However, the detailed lymphocyte statuses of USpA patients and the effect of regulating the intestinal flora on the lymphocyte subsets is unclear. Objectives: To investigate the status of lymphocyte subsets in peripheral blood (PB) of USpA patients and the variation after regulation of intestinal flora. Methods: A total of 39 newly diagnosed patients with USpA who fulfilled the European Spondyloarthropathy Study Group (ESSG) classification criteria and 60 age- and sex- matched healthy controls (HC) were enrolled in this study. All patients were given intestinal flora regulation therapy for six months, including clostridium butyricum capsule or bacillus coagulans tablet. The peripheral lymphocyte subsets of these participants were assessed by flow cytometry. Methane hydrogen breath test as well as cytokines were measured in all patients before and after treatment. Mann-Whitney U test was applied for the lymphocyte status between USpA patients and HC and Wilcoxon test for the comparison before and after treatment. The results of methane hydrogen breath were counted by the Chi-Square test. All P -values reported herein are two-tailed and P -value&lt;0.05 was taken as statistically significant. Results: Compared with HC, patients with USpA had a lower numbers of T cells ( P =0.001), NK cells ( P =0.026), CD8+T cells ( P =0.046) and Treg cells ( P &lt;0.05) but higher ratios of Th17/Tregs ( P =0.001), indicating a disturbance of immune microenvironment (Figure 1). After given therapy, T cells ( P= 0.003), B cells ( P =0.018), NK cells ( P= 0.003), CD8 + T cells ( P= 0.001) and Treg cells ( P= 0.009) were distinctly increased while the ratio of Th17/Treg decreased ( P= 0.046), suggesting a rebalance of immune systems (Figure 2a-c). Moreover, there were increase in the level of IL-6 ( P &lt;0.001), IL-17 ( P= 0.029) and TNF-α ( P= 0.003) as well as decrease in IL-10 ( P= 0.045) and IFN-γ ( P =0.001) (Figure 2d). Further, the positive rate of intestinal bacterial overgrowth decreased significantly after regulation ( P= 0.029) (Figure 2e). Conclusion: Imbalance of immune environment is closely related to the incidence of undifferentiated spondyloarthrosis. The regulation of intestinal flora restores the balance and improve the growth of bacteria in the small intestine simultaneously. Therefore it is essential to focus on the alteration of intestinal flora to prevent the outbreak of inflammation and disease progression. References: [1]Cruzat V, Cuchacovich R, Espinoza LR. Undifferentiated spondyloarthritis: recent clinical and therapeutic advances. Curr Rheumatol Rep 2010;12(5):311-7. doi: 10.1007/s11926-010-0115-0 [published Online First: 2010/07/16]. [2]Deodhar A, Miossec P, Baraliakos X. Is undifferentiated spondyloarthritis a discrete entity? A debate. Autoimmun Rev 2018;17(1):29-32. doi: 10.1016/j.autrev.2017.11.006 [published Online First: 2017/11/08]. [3]Sheth T, Pitchumoni CS, Das KM. Management of Musculoskeletal Manifestations in Inflammatory Bowel Disease. Gastroenterol Res Pract 2015;2015:387891. doi: 10.1155/2015/387891 [published Online First: 2015/07/15]. [4]Fragoulis GE, Liava C, Daoussis D, et al. Inflammatory bowel diseases and spondyloarthropathies: From pathogenesis to treatment. World J Gastroenterol 2019;25(18):2162-76. doi: 10.3748/wjg.v25.i18.2162 [published Online First: 2019/05/31]. Acknowledgements: This project was supported by National Science Foundation of China (82001740), Open Fund from the Key Laboratory of Cellular Physiology (Shanxi Medical University) (KLCP2019) and Innovation Plan for Postgraduate Education in Shanxi Province (2020BY078). Disclosure of Interests: None declared