Ventricular fluid interleukin-1 activity in patients with head injury

Patients with severe head injury are hypermetabolic and hypercatabolic, and manifest several components of the acute phase response. Interleukin-1 (IL-1) is a cytokine that mediates many aspects of the acute phase response, and rats with experimental head injury produce IL-1 of brain origin. IL-1 administered intracerebroventricularly to experimental animals has disproportionately greater systemic biologic effects compared with IL-1 injected intravenously. In this study, patients with severe head injury were evaluated to determine whether IL-1 activity in the ventricular fluid was increased and whether IL-1 levels correlated with some of the altered metabolic responses. Twelve hospitalized patients with head injury (24-hour peak admission Glasgow Coma Scale scores of 4 to 10) were evaluated on admission and longitudinally for 21 days after injury. IL-1 activity in ventricular fluid from patients with head injury was significantly elevated whereas IL-1 activity in cerebrospinal fluid from age- and sex-matched patients undergoing lumbar puncture for myelograms was not detectable (P less than 0.005). The patients with head injury had clinical and biochemical indicators of IL-1 activity such as fever, hypozincemia, and increased C-reactive protein levels that improved during the period of hospitalization. It is speculated that the elevated IL-1 activity may play a role in the altered metabolic response of patients with severe head injury.