SAT0013 CHANGES AND SIGNIFICANCE OF CD4+CD25+FOXP3+TREG CELLS IN THE PERIPHERAL BLOOD OF PATIENTS WITH AUTOIMMUNE DISEASES
Authors: Yanan Duan, Hong-Yan Wen, Yang Liu, Sheng-Xiao Zhang, Ming Yan, LI Xiao-Feng, Chong Gao
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> In recent years, studies have found that the maintenance of immune tolerance of Treg cells palys a pivotal role in the occurrence and development of AID, and that the mutual regulation and dynamic equilibrium between Treg cell and other T lymphocyte plays a significant role in maintaining the immune hemostasis within the body.Therefore, the present research proposes to explore the status of the absolute numbers of Treg cells among various AID patients and correlation with disease activity using a large sample. <h3>Objectives:</h3> To determine CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+</sup>T regulatory (Treg) cell levels in peripheral blood (PB) of patients with autoimmune diseases (AID) and age- and sex-matched healthy controls, and to explore the correlation between the levels of peripheral Treg cells and clinical parameters in AID. <h3>Methods:</h3> A total of 1561 AID patients, and 196 age- and sex-matched healthy controls were enrolled. The absolute numbers of CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+</sup>Treg and other T subsets [total T, CD4<sup>+</sup>T, CD8<sup>+</sup>T, T helper 1 (Th1), T helper 2 (Th2), and T helper 17 (Th17) cells] in PB were measured by Flow Cytometer (FCM). Erythrocyte sedimentation rate (ESR) was analyzed by the Westergren method. Serum concentrations of C-reactive protein (CRP) were measured by monoclonal immunoassay. <h3>Results:</h3> <b>(1)</b> The absolute numbers of Treg cells in PB of patients with AID [22.90 (18.31, 36.47)] were significantly lower than those of healthy controls [30.24 (21.85, 41.34); <i>p</i>&lt;0.05), which was also seen in rheumatoid arthritis (RA), Sjogren's syndrome (SS), systemic lupus erythematosus (SLE), systemic vasculitis (SV), idiopathic inflammatory myopathy (IIM) and other diseases. The levels of CD4<sup>+</sup>T, Th1/Treg, and Th2/Treg in PB of AID patients were higher than those of healthy controls. <b>(2)</b> The absolute numbers of most T cell subsets in PB of most AIDs were lower than those of healthy controls, but the Treg cells were greatly decreased, so the ratio of Treg to other T lymphocyte subsets were higher than those of healthy controls. <b>(3)</b> The levels of inflammatory indicators were inversrly associated with numbers of Tregs, total T, CD4<sup>+</sup>T, CD8<sup>+</sup>T, Th1 and Th1/Treg cells. <h3>Conclusion:</h3> In AID, the absolute numbers or function of CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+</sup>Treg cells were decreased, so it cannot effectively maintain immune tolerance or inhibit inflammatory response, which may be one of the important mechanisms of disease. Treatment promoting CD4<sup>+</sup>CD25<sup>+</sup>Foxp3<sup>+</sup>Treg cell function may become a new strategy for AID therapy. <h3>References</h3> [1] Tao JH, Cheng M, Tang JP, et al. Foxp3, Regulatory T Cell, and Autoimmune Diseases [J]. Inflammation. 2017;40(1):328-339. [2] Dall'Era M, Pauli ML, Remedios K, et al. Autoimmunity Centers of Excellence. Adoptive Regulatory T Cell Therapy in a Patient with Systemic Lupus Erythematosus [J]. Arthritis Rheumatol. 2018 Oct 1. [3] Yokoyama Y, Iwasaki T, Kitano S, et al. IL-2-Anti-IL-2 Monoclonal Antibody Immune Complexes Inhibit Collagen-Induced Arthritis by Augmenting Regulatory T Cell Functions [J]. J Immunol. 2018;201(7):1899-1906. [4] Zhang SX, Ma XW, Li YF, et al. The Proportion of Regulatory T Cells in Patients with Systemic Lupus Erythematosus: A Meta-Analysis [J]. J Immunol Res. 2018;2018:7103219. [5] Moulton VR, Suarez-Feuyo A, Meidan E, et al. Pathogenesis of human systemic lupus erythematosus: a cellular perspective [J]. Trends Mol Med. 2017,23(7):615-635. [6] Zhao Z, Zhang X, Su L, et al. Fine tuning subsets of CD4(+) T cells by low-dosage of IL-2 and a new therapeutic strategy for autoimmune diseases [J]. Int Immunopharmacol. 2018,56:269-276. <h3>Acknowledgement:</h3> Thanks for my teachers, classmates, and my family. <h3>Disclosure of Interests:</h3> None declared