ABNORMALITY OF PERCENTAGES AND ABSOLUTE NUMBERS OF CD4+T SUBSETS IN PATIENTS WITH ANCA-ASSOCIATED VASCULITIS AND ITS CORRELATIONS WITH CLINICAL INDICATORS

Background: ANCA-associated vasculitis (AAV) is a heterogenous autoimmune disease with unknown etiology [1-2]. During the last decade, a panel of CD T subsets have been identified. However, the exact role and quantitative status of these subsets in AAV patients remains unclear. Objectives: We therefore investigated these T cell subsets in AAV patients. Methods: AAV patients (n = 54) and healthy controls (HCs) (n = 19) were enrolled. Of them, ten patients initially presenting with active disease were assessed again after remission was achieved. In addition, 38 patients were renal vasculitis. Proportions and absolute numbers of peripheral CD4+T cell subsets and expression of multiplex cytokines were determined by flow cytometry (FCM). Correlations of clinical indicators with the CD4+ T cell subsets were systematically analyzed. Results: Percentages of naive T cells (TN) (p<0.001), terminally differentiated effector (TEMRA) T cells (p=0.027) and activated Treg cells (aTreg) in AAV patients were decreased, but those of effector memory T-cell subpopulation (TEM) (p<0.001), regulatory T cell (Treg) cells and FoxP3lowCD45RA- T cells were increased. Similar results were observed when we compared absolute numbers of the above corresponding cells in AAV patients and HCs, except TEM. Furthermore, the percentage of aTreg (p=0.043) was decreased while that of Th17 cells (p=0.027) was increased in renal vasculitis patients. A significant correlation was observed between the ratio of Th17 to Treg subset and creatinine or BUN, as well as the ratio of Th17/aTreg was significantly increased in active and renal vasculitis patient. In addition, we found that cytokine IL-2 and IL-4 exhibited a downward while IL-6, IL-10, TNF, IFN-γ and IL-17A trend upward in AAV patients. Conclusion: There were abnormally quantitative changes in CD4+ T subsets and cytokines in AVV patients, especially the decrease in the relative and absolute number of aTreg (activated Tregs), which indicates an imbalance of pro- and anti-inflammatory T cells. These T subsets might be associated with the ANCA-related autoimmune response and can be used as diagnosis markers for disease activity and as targets for potentially powerful therapy of AAV. REFERENCES: [1] Hutton H L, Holdsworth S R, Kitching A R. ANCA-Associated Vasculitis: Pathogenesis, Models, and Preclinical Testing [J]. Seminars in Nephrology, 2017, 37(5):418. [2] Kerstein A, Silke Schüler, Otávio CabralMarques, et al. Environmental factor and inflammation-driven alteration of the total peripheral T-cell compartment in granulomatosis with polyangiitis [J]. Journal of Autoimmunity, 2016, 78:79. Disclosure of Interests: None declared DOI: 10.1136/annrheumdis-2019-eular.4667Citation: Ann Rheum Dis, volume 78, supplement 2, year 2019, page A830Session: Vasculitis (Scientific Abstracts)