AB0490 CIRCULATING REGULATORY T CELLS WERE ABSOLUTELY DECREASED IN TAKAYASU’S ARTERITIS PATIENTS
Authors: W. Jia, J. Xie, X. Wang, C. Gao, G. Liu, J. Luo, X. C. Zhao
Journal: Annals of the Rheumatic Diseases (2020)

Background: Takayasu arteritis (TA) refers to chronic progressive non-specific inflammation that involves the aorta and its main branches, causing stenosis and occlusion of arteries in different parts, and ischemic manifestations in the corresponding parts. A variety of immune dysfunctions are involved in the occurrence and development of TA (1) Recent studies have shown that Th17/Treg imbalance plays an important role in the pathogenesis of Takayasu’s arteritis, in which T help 17 cells (Th17) cells are up-regulated in TA patients (2) . Th17 cells are closely related to Treg cells during differentiation. There are few studies on the expression level of CD4+CD25+FOX3+T lymphocyte (Treg) cells. This study aims to study the clinical significance of Treg cell expression in peripheral blood of patients with Takayasu’s arteritis. Objectives: To analyze the levels of circulating lymphocyte subsets and serum cytokines in patients with takayasu arteritis (TA), and explore the relationship between their changes and TA disease activity. Methods: A total of 46 TA patients and 43 gender-age-matched healthy controls were enrolled. According to the NIH standard, 30 patients were in active disease. Flow cytometry was used to detect the absolute numbers and ratios of Th1, Th2, Th17 and Treg cells in peripheral blood of all subjects. Magnetic bead-based multiplex immunoassay was used to detect cytokines and statistical analysis was performed. Results: Compared with the healthy controls, the absolute number and proportion of peripheral Treg cells of TA patients significantly decreased while those of Th17 cells increased significantly, leading to the increased ratio of Th17 / Treg. Compared with the inactive group, the TA active group had significantly increased IL-6 and TNF-α, and there was no significant difference in the expression of Th17 cells and Treg cells. Conclusion: In peripheral blood of TA patients, Treg cells decreased, while Th17 cells increased as compared with healthay controls, leading to an imbalance between Th17 and Treg cells. The levels of IL-6 and TNF-α were related to disease activity. References: [1]Russo, R.A.G. and M.M. Katsicas, Takayasu Arteritis. Front Pediatr, 2018. 6: p. 265. [2]Misra, D.P., S. Chaurasia, and R. Misra. Increased Circulating Th17 Cells, Serum IL-17A, and IL-23 in Takayasu Arteritis. Autoimmune Dis, 2016. 2016: p. 7841718. Figure 1. Characteristics of the absolute numbers and proportions of Th1cells,Th2cells,Th17 cells and CD4Treg cells in the PB of patients with TA.(A-C)The levels of Th17 cells and the ratio of Th1/Treg,Th2/Treg,Th17/Treg in PB were significantly increased in patients with TA (n=46). The absolute number and the proportion of CD4Treg cells were significantly decreased in TA(n=46). (D-F) The absolute number of Th2 cells and ratio of Th2/Treg in PB were significantly decreased in active patients with TA (n=30).Neither the absolute number nor proporation of Th1, Th17 and Treg cells was altered significantly between active TA patients(n=30) and inactive TA patients(n=16).*P&lt;0.05; **P&lt;0.001. P&lt;0.05 was considered statistically significant.TA,takayasu arteritis;PB peripheral blood;Tregs, regulatory Tcells. Figure 2. Characteristics of serum concentrations of cytokine (including IL-6, IL-10, IL-17 and TNF-α) between active TA patients(n=30) and inactive TA patients(n=16).(A,D)In terms of cytokines, the concentration of IL-6 and TNF-α was significantly up-regulated,(B,C)but no significant changes in IL-10, and IL-17 were found.*P&lt;0.05; **P&lt;0.001. P &lt; 0.05 was considered statistically significant. Disclosure of Interests: None declared