Objective: To explore the dynamic changes of serum interleukin-6 (IL-6) and IL-8 in acute traumatic brain injury (TBI) and their correlations to the severity of brain injury and the condition of the patients.
Methods: Thirty-four patients with acute TBI were divided into two groups according to the Glasgow Coma Scale (GCS) score, clinical manifestations and the imaging data, namely patients with GCS score < or = 8 and those with GCS score between 9 and 12. Radioimmunoassay was employed to determine the serum levels of IL-6 and IL-8 at 6 different time points within 15 days after the injury in the two groups.
Results: The serum IL-6 reached the peak level on the second day after the injury in patients with GCS score < or = 8 and on the 7th day in patients with GCS score of 9-12, showing significant differences in IL-6 variations between the two groups (P=0.046). The peak serum level of IL-8 occurred on the 7th day in patients with GCS score < or = 8 and on the 3rd day in patients with GCS score of 9-12, also showing significant differences (P=0.045). The peak level of IL-6 on the second day after the injury was significantly higher than the peak level of IL-8 that occurred on the 7th day, demonstrating significant differences in the variations of IL-6 and IL-8 after the injury (P=0.000).
Conclusion: The changes of serum IL-6 and IL-8 levels show positive correlations to the severity of the condition of the patients sustaining TBI. IL-6 variation is more obvious than that of IL-8 without intimate correlations between them. Clinically, serum IL-6 level can be more informative than serum IL-8 level in evaluating the changes of the condition of the TBI patients in early stage following the injury.