Correlation between serum IL-6 and CRP levels and severity of head injury in children

Objective: To examine interleukin-6 (IL-6) and C-reactive protein (CRP) release in children with head injury (HI) and investigate if there is a correlation between the levels of these two proteins and the severity of HI. Design: Prospective clinical investigation. Setting: Eight-bed paediatric intensive care unit in a university hospital. Patients: Forty-five children were followed up for 4 days after HI and their serum IL-6 and CRP levels were measured. Measurements and results: Peak serum IL-6 levels occurred 4 h post-injury, decreasing over time. CRP was normal 4 h after injury, then increased reaching peak levels in 48 h. Children with admission Glasgow Coma Scale (GCS) scores of 8 or less had higher IL-6 levels compared to children with GCS scores higher than 8, 4 and 12 h post-injury (p < 0.01 and p < 0.05, respectively). IL-6 was higher in children with admission PRISM scores of 10 or more than in those with PRISM scores lower than 10 at 4 and 12 h (p < 0.05). CRP levels were higher in patients with GCS scores of 8 or less compared to patients with GCS scores higher than 8 at 24, 48 and 72 h (p < 0.05, p < 0.02 and p < 0.02, respectively) . Patients with PRISM scores of 10 or more had higher CRP levels compared to those with PRISM scores lower than 10 at 24, 48 and 72 h (p < 0.05). Peak CRP levels correlated well with peak IL-6 levels (r = 0.49, p < 0.001). No correlation between IL-6 or CRP levels and mortality or clinical outcome was found. Conclusions: Serum IL-6 and CRP levels are elevated in children with HI and there is a relation between the severity of HI and the levels of these proteins. There was no correlation between IL-6, CRP and outcomes of the patients.