Pos0200 Risk Factor Analysis of the Clinical Characteristics and Peripheral Immunophenotypes in Anca-Associated Vasculitis Patients Complicated With Venous Thromboembolism

Background: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare but life-threatening multisystemic autoimmune disease including microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic granulomatosis with polyangiitis (EGPA). The clinical symptoms of patients with AAV are complex, manifested as variations from mild non-specific symptoms to severe life-threatening organ involvements. Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) is also a common complication of AAV. Recent reports have highlighted an increased frequency of VTE in patients with AAV, but the risk factors of it remain ill-defined. Objectives: To determine the risk factors of AAV patients complicated with VTE in the characteristics of clinical manifestation and peripheral immunophenotypes. Methods: We retrospectively collected the data of 138 patients with AAV from the Second Hospital of Shanxi Medical University between November 2014 and July 2023 including 24 AAV patients complicated with VTE. The clinical characteristics of patients included demographics, disease duration, disease activity indicators Birmingham Vasculitis Activity Score (BVAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the involved organ and system (including kidney, lung, nervous system, heart, digestive system, ear/nose/throat) as well as laboratory tests (including the detection of ANCA, liver function, kidney function, and blood routine). The peripheral immunophenotypes included the percent and the number of total T, B, NK, CD4+ T, and CD8+ T cells, as well as the CD4+T cell subsets T helper (Th) 1, Th2, Th17 and regulatory T(Treg) cells. We aimed to analyze the risk factors for AAV complicated with VTE in the aspect of clinical manifestation and peripheral immunophenotypes by multivariable logistical analysis. All P-values were two-tailed and statistical significance was defined as P Results: In the clinical characteristics, the AAV-VTE group exhibited higher disease activity indicators including BVAS and ESR, and the organ and system involvement, especially the heart, than the AAV-no-VTE group. The ratio of patients with EGPA in the AAV-VTE group was higher than those in the AAV-no-VTE group. As for the laboratory tests, AAV-VTE group showed higher white blood cells(P=0.002) and eosinophil (P=0.005). The analysis of peripheral immunophenotypes was conducted to identify the role of immune cells in AAV with VTE preliminarily. It showed that compared with AAV-no-VTE group, the AAV-VTE group had the higher NK cells (P=0.004) but the lower Th2 cells (P=0.012) and Treg cells (PP=0.002) (Table 1). The logistic regression analysis was conducted to identify the risk factors of AAV with VTE (Table 2). The univariate logistic regression analysis revealed that EGPA, BVAS, ESR, heart involvement, BUN, D-Dimer, white blood cells, eosinophil and NK cells were the risk factors of AAV with VTE. However, Th2 cells and Treg cells were the protective factor of AAV with VTE. After excluding variables with P-values ≥0.05, the factors with a P value of less than 0.05 in the univariable logistic regression analysis were considered in multivariate logistic regression analysis. The multivariate logistic regression analysis showed that heart involvement and the increased NK cells were the risk factors of AAV with VTE. Conclusion: AAV patients with VTE had a higher disease activity, a higher proportion of heart involvement, increased white blood cells and eosinophils, as well as abnormal peripheral immunophenotypes including higher NK cells but lower Th2 and Treg cells. The risk factor analysis showed that heart involvement and increased NK cells were the risk factors of AAV with VTE. Our results highlighted the characteristics of clinical manifestation and peripheral immunophenotypes of AAV patients complicated with VTE. In clinical practice, attention should be paid to the possibility of VTE events in patients with AAV, especially patients with cardiac involvement and increased NK cells. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.