Alteration of Interleukin-6 Levels in Serum and Cerebrospinal Fluid after Head Injury in Adults

ABSTRACT

OBJECTIVE: The cytokine interleukin-6(IL-6) plays a major role in initiating the acute phase response, especially in the production of acute phase reactants. The objective of this study is to determine whether serum IL-6 and cerebrospinal fluid(CSF) IL-6 levels were elevated at time of admission after head injury, serum IL-6 and CSF IL-6 levels related temporally to clinical improvement, severity of head injury with Glasgow Coma Scale(GCS) score and increased intracranial pressure(IICP). METHODS: All 21 patients(19 males and 2 females) with brain injury, managed in our institute between Aug 1996 and Jun 1998 were included in this study. Serum samples from all the 21 patients and CSF samples from 12 patients with low GCS score were analyzed for IL-6. IL-6 determination with enzyme-linked ELISA kits obtained from Quantikine(r). RESULTS: The values of IL-6 in serum and CSF in 21 patients with GCS score between 4 and 14(mean=9) were observed for 3-5 days after head injury. Peak elevation of serum IL-6 was observed on first day(8.2+/-4.9pg/ml) and then decreased to 4.0+/-3.6pg/ml on fifth day. Serum IL-6 levels decreased significantly faster in patients with GCS score of 8 through 11, compared with those of GCS score below 8. The patients showed markedly elevated and variable CSF IL-6 levels on admission(46.6+/-4.2pg/ml;normal, below 20.6+/-5.8pg/ml). CONCLUSION: This study demonstrates that the IL-6 level is related to the severity of traumatic brain injury.