Rongyi Chen1,2, Lingying Ma1,2, Peng Lv3, Jiang Lin3, Chaolun Li4, Yan Yan1,2, Xuejuan Jin5, Xiaomin Dai1,2, Zongfei Ji1,2, Huiyong Chen1,2, Lili Ma1,2, Ying Sun6,7, Lindi Jiang8,9. 1. Department of Rheumatology, Zhongshan Hospital, Fudan University, Shanghai, China. 2. Evidence-Based Medicine Centre, Fudan University, No.180, Fenglin Road, Xuhui District, Shanghai, 200032, China. 3. Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China. 4. Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China. 5. Cardiovascular Epidemiology, Zhongshan Hospital, Fudan University, Shanghai, China. 6. Department of Rheumatology, Zhongshan Hospital, Fudan University, Shanghai, China. sun.ying1@zs-hospital.sh.cn. 7. Evidence-Based Medicine Centre, Fudan University, No.180, Fenglin Road, Xuhui District, Shanghai, 200032, China. sun.ying1@zs-hospital.sh.cn. 8. Department of Rheumatology, Zhongshan Hospital, Fudan University, Shanghai, China. jiang.lindi@zs-hospital.sh.cn. 9. Evidence-Based Medicine Centre, Fudan University, No.180, Fenglin Road, Xuhui District, Shanghai, 200032, China. jiang.lindi@zs-hospital.sh.cn.
Abstract
BACKGROUND: Takayasu arteritis (TA) is a rare disease, lacking convenient and feasible biomarkers to identify disease activity. We aimed to evaluate the value of complements in distinguishing active TA. METHODS: Consecutive patients were enrolled from the prospective East China TA cohort from April 2008 to June 2019. Patients were divided into two groups according to their baseline Kerr score. The value of complements and other biomarkers in identifying disease activity were analysed with cluster analysis, ROC curves, and combined tests. An independent group of patients from July 2019 to December 2019 were employed to validate the results. RESULTS: Of the enrolled 519 patients, 406 (72.2%) cases were identified as active disease. Higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), and complement 3 (C3) levels were observed in the active group. Elevated C3 (≥ 1.085 g/L) had a high value to identify active TA with a sensitivity of 69.9%, specificity of 66.7%, and AUC of 0.715. Combining the CRP (≥ 10.65 g/L; sensitivity, 50.7%; specificity, 82.4%) and C3, the sensitivity could be improved to 85.1% in parallel test and the specificity could be improved to 94.1% in serial test. Validation was further performed to confirm the value of C3 for disease activity assessment. The accuracy of the parallel test of CRP and C3 in external validation with independent 53 TA cases was 72.73% with the AUC of 0.721. CONCLUSION: Elevated C3 could effectively evaluate the disease activity of TA, and C3 combining with CRP could further improve the disease activity evaluation.
BACKGROUND: Takayasu arteritis (TA) is a rare disease, lacking convenient and feasible biomarkers to identify disease activity. We aimed to evaluate the value of complements in distinguishing active TA. METHODS: Consecutive patients were enrolled from the prospective East China TA cohort from April 2008 to June 2019. Patients were divided into two groups according to their baseline Kerr score. The value of complements and other biomarkers in identifying disease activity were analysed with cluster analysis, ROC curves, and combined tests. An independent group of patients from July 2019 to December 2019 were employed to validate the results. RESULTS: Of the enrolled 519 patients, 406 (72.2%) cases were identified as active disease. Higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin-6 (IL-6), and complement 3 (C3) levels were observed in the active group. Elevated C3 (≥ 1.085 g/L) had a high value to identify active TA with a sensitivity of 69.9%, specificity of 66.7%, and AUC of 0.715. Combining the CRP (≥ 10.65 g/L; sensitivity, 50.7%; specificity, 82.4%) and C3, the sensitivity could be improved to 85.1% in parallel test and the specificity could be improved to 94.1% in serial test. Validation was further performed to confirm the value of C3 for disease activity assessment. The accuracy of the parallel test of CRP and C3 in external validation with independent 53 TA cases was 72.73% with the AUC of 0.721. CONCLUSION: Elevated C3 could effectively evaluate the disease activity of TA, and C3 combining with CRP could further improve the disease activity evaluation.