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Analyses of Proteinuria, Renal Infiltration of Leukocytes, and Renal Deposition of Proteins in Lupus-prone MRL/lpr Mice
Published on: June 8, 2022
Circulating anti-C3b IgG in lupus nephritis: A large cohort study
Juan Tao1, Di Song1, Xiao-Ling Liu2
1Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, PR China; Institute of Nephrology, Peking University, Beijing 100034, PR China; Key Laboratory of Renal Disease, Ministry of Health of China, Beijing 100034, PR China; Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing 100034, PR China.
Abstract:
The current study aimed to analyze the clinical significance and bio-functional properties of anti-C3b IgG based on a lupus nephritis cohort. We found that the prevalence of anti-C3b IgG in our cohort was 47.8%. Patients with positive anti-C3b IgG had significantly higher SLEDAI, lower circulating C3 and C4 levels. Anti-C3b IgG levels were positively correlated with C3 or C1q deposition in kidneys and several active pathological lesions. The positivity of anti-C3b IgG was an independent risk factor for the composite endpoints in the subgroup of proliferative lupus nephritis patients. In vitro, the purified IgG fractions from positive patients resulted in increased C3a generation through the alternative pathway, and interfered factor H and CR1 binding to C3b. Our findings indicated that anti-C3b IgG associated with local renal injury and long-term outcomes in lupus nephritis patients, possibly through leading to the complement alternative pathway over-activation.

