AB1259 EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS HAS ELEVATED SERUM SOLUBLE INTERLEUKIN-2 RECEPTOR LEVELS
Authors: R. Su, B. C. LI, L. Cheng, C. Wang
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Eosinophilic granulomatosis with polyangiitis is a typical autoimmune disease, however, the pathogenesis of EGPA is still not fully elucidated, and a variety of cytokines may be involved in the imbalance of immune status in EGPA [1,2]. However,serum soluble interleukin-2 receptor levels in patients with EGPA are unknown. Exploring the cytokine levels of EGPA can help inform accurate treatment strategies. <h3>Objectives:</h3> In this study, the levels of peripheral blood cytokines were compared in three parts, namely EGPA patients with healthy controls, patients with inactive EGPA and active EGPA, and patients with EGPA with multisystem involvement and non-multisystem involvement. The correlation between serum soluble interleukin-2 receptor levels and interleukin-2 levels and BVAS scores was analyzed. The ROC curves of serum soluble interleukin-2 receptor and interleukin 2 levels were drawn to evaluate the disease activity and multisystem involvement of EGPA. <h3>Methods:</h3> In this study, 45 healthy controls and 34 patients with EGPA were included in the study and were divided into 18 patients with inactive EGPA and 16 patients with active EGPA (BVAS score≥15) according to the Birmingham Vasculitis Score (BVAS), and were divided into multisystem involvement (organ involvement≥1) and non-multisystem involvement based on the presence or absence of organ involvement (cardiac, kidney, lung, nervous system). Clinical and laboratory data were collected retrospectively from these patients. Flow cytometric bead array was used to detect serum cytokine levels. <h3>Results:</h3> Cytokine analysis showed that the levels of each cytokine in EGPA patients were higher than those in the healthy control group (P&lt;0.001), and further analysis showed that the sIL-2R level was significantly increased in both active EGPA and inactive EGPA patients, and between the multi-system and non-multisystem involved groups. In terms of correlation studies, we found that sIL-2R levels (r=0.4997, P=0.0026) and IL-2 levels (r=0.3498, P=0.0425) were positively correlated with BVAS scores. Receiver operating characteristic (ROC) curve analysis showed that serum sIL-2R and IL-2 levels promoted the detection of disease activity in EGPA patients, with the area under the ROC curve (AUC) 0.760 (95% CI 0.599–0.922, P=0.010) and 0.719 (95% CI 0.545–0.892, P=0.030), and more importantly, serum sIL-2R levels facilitated the detection of multisystem involvement in patients with EGPA, with an area under the ROC curve (AUC) of 0.879 (95% CI 0.757–1.000, P=0.001). <h3>Conclusion:</h3> Our study clearly shows that elevated sIL-2R concentrations were observed in EGPA patients, showing a significant correlation with disease activity, suggesting that sIL-2R may be involved in the immunopathogenesis of EGPA. This study highlighted that serum sIL-2R level is a reliable biomarker for EGPA disease activity and multisystem involvement, which provides a reference for future clinical evaluation of the disease. <h3>REFERENCES:</h3> [1] Ma J, Dong C, Wei S, et al. Serum Cytokine Profiling Identifies Axl as a New Biomarker Candidate for Active Eosinophilic Granulomatosis With Polyangiitis. <i>Front Mol Biosci.</i> 2021;8:653461. [2] Pagnoux C, Nair P, Xi Y, et al. Serum cytokine and chemokine levels in patients with eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome, or eosinophilic asthma. <i>Clin Exp Rheumatol.</i> 2019;37 Suppl 117(2):40-44. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>