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Updated: May 8, 2026
Methods for Quantitative Detection of Antibody-induced Complement Activation on Red Blood Cells
Published on: January 29, 2014
Usefulness of complement activation products in Chinese patients with systemic lupus erythematosus
Juan Li1, Lemei An, Zhuoli Zhang
1Rheumatology and Clinical Immunology Department, Peking University First Hospital, Beijing, China; Renal Department, General Hospital of Tisco, Shanxi, China. xiaodaizi.521@163.com.
Objectives:
To evaluate the roles of complement activation products C3d and C4d binding to lymphocytes in the diagnosis of systemic lupus erythematosus (SLE) in a Chinese cohort of patients.
Methods:
96 patients with SLE, 44 patients with other autoimmune disease and 40 healthy control individuals were enrolled in this study. The levels of C3d and C4d binding to peripheral CD4+ T and CD19+ B lymphocyts (designated as T-C3d, T-C4d, B-C3d, B-C4d ) was assessed by flow cytometry. The diagnostic values of these biomarkers were determined by receiver-operator characteristic analysis.
Results:
The levels of T-C3d, T-C4d, B-C3d, B-C4d were significantly higher in SLE patients than patients with other disease and healthy controls (p<0.01). As diagnostic tools, T-C4d and B-C4d were 61.1% sensitive/94.3% specific and 63.9% sensitive/94.3% specific in differentiating SLE patients from patients with other disease and healthy controls, respectively. T-C4d and B-C4d were significantly associated with SLE disease activity as measured by the SLE disease activity index (SLEDAI) (p<0.001), low serum C3 (p<0.001), low serum C4 (p=0.006), anti-dsDNA (IIF) (p=0.001), and anti-dsDNA (ELISA) (p=0.001).
Conclusions:
Complement activation products C3d and C4d binding to lymphocytes can reflect the disease activity of SLE and can be used as biomarkers for SLE.
