C4A and systemic lupus erythematosus: Based on this meta-analysis, the additional use of Qinghao Biejia decoction is not only superior to chemical medicine alone in people with SLE in terms of improving the overall response rate, reducing SLEDAI and TCM symptom scores, but also significantly improving immunological indicators, manifested in IgG and IgA decreased, C3 and C4 levels increased, cytokine balance restored.