[Correlation between soluble CD146 and systemic vasculitis].

Objective: To determine the correlation between serum soluble CD146 (sCD146) levels and disease activity in patients with systemic vasculitis and the potential of sCD146 as a novel biomarker. Methods: We recruited 304 patients from the systemic vasculitis cohort at Peking Union Medical College Hospital from July 2013 to December 2022. The cohort comprised 200 patients with Takayasu arteritis (TAK) and 104 with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). The patient's demographic and clinical data, including age, sex, disease duration, disease type, laboratory results, and disease status, were extracted from the database. The serum sCD146 concentration was measured using a sandwich enzyme-linked immunosorbent assay (ELISA). Continuous variables were presented as mean±standard deviation if normally distributed, with between-group comparisons conducted using the t-test. For non-normally distributed data, median (Q₁,Q₃) was used, and comparisons between groups were performed using the Mann-Whitney U test. Categorical data were expressed as percentages, and comparisons between groups were conducted using the Chi-square test or Fisher's exact test,as appropriate. Kendall's tau-b's rank correlation coefficient was calculated to evaluate the correlation between sCD146 and variables associated with systemic vasculitis. A two-sided P value <0.05 was considered statistically significant. Results: Serum sCD146 levels were significantly lower in patients with active disease compared to those in remission in both cohorts [TAK: 246 (218, 287) vs. 277 (230, 322) μg/L, Z=-2.58, P=0.010; AAV: (301±90) vs. (344±81) μg/L, t=-2.56, P=0.007]. Serum sCD146 levels were positively correlated with age and disease duration (TAK: τ=0.09, 0.12, P=0.040, P=0.009; AAV: τ=0.28, 0.15, P<0.001, P=0.020). In patients with TAK, sCD146 levels were negatively correlated with IL-6, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity status (τ=-0.17, -0.18, -0.16, -0.16; P=0.001, P<0.001, P=0.003, P=0.010). In patients with AAV, sCD146 levels were negatively correlated with platelet count (PLT),disease activity status,and the Birmingham Vasculitis Activity Score (τ=-0.36, -0.27, -0.27; P<0.001, P=0.007, P=0.001). Conclusion: Serum sCD146 levels were significantly lower in patients with active systemic vasculitis than in remission, displaying a negative correlation with disease activity. These findings suggest that sCD146 has potential as a novel biomarker for assessing disease activity in systemic vasculitis.