High plasma complement C4 levels as a novel predictor of clinical outcome in intracerebral hemorrhage.

Objective: The complement cascade is activated and contributes to the brain injury after intracerebral hemorrhage (ICH). Complement component 4 (C4), an important component of complement cascade, has been associated with severity of neurological impairment that occurs during ICH. However, the correlation of plasma complement C4 levels with hemorrhagic severity and clinical outcome in ICH patients has not been reported. Materials and methods: This study is a monocentric, real-world, cohort study. In this study, we measured the plasma complement C4 levels of 83 ICH patients and 78 healthy controls. The hematoma volume, the National Institutes of Health Stroke Scale (NIHSS) score, the Glasgow Coma Scale (GCS) score, and the permeability surface (PS) were used to assess and quantify neurological deficit following ICH. Logistic regression analysis was configured to determine the independent relation of plasma complement C4 levels to hemorrhagic severity and clinical outcomes. The contribution of complement C4 to secondary brain injury (SBI) was assessed by changes in plasma C4 levels between admission and at day 7 after ICH. Results: There was a significant elevation of plasma complement C4 levels in ICH patients than in healthy controls (40.48 ± 1.07 vs. 35.25 ± 0.60, Conclusion: Plasma complement C4 levels are significantly elevated in ICH patients and positively correlated with the illness severity. Thus, these findings highlight the importance of complement C4 in brain injury after ICH and provide a novel predictor of clinical outcome for this disease.