Central nervous system interleukin-8 production following neck of femur fracture

Aim: To establish a proinflammatory cytokine profile of the cerebrospinal fluid (CSF) following trauma. Background: Trauma is associated with a postinjury syndrome consisting of loss of weight and nitrogen, pyrexia, anorexia and fatigue. It has been proposed that cytokines are pathophysiologically involved in this syndrome but the site of action of these is unclear. Previous work in head injury models, supported by animal work, has suggested that one important site of action is the central nervous system (CNS). Methods: Women who had sustained neck of femur fractures were enrolled (trauma group). CSF was collected at the time of spinal anaesthetic. Women undergoing elective lower limb surgery were recruited as controls. CSF and serum were assayed for Interleukin (IL) 1, 2, 4, 6, 8, 10, 12, interferon gamma, and tumour necrosis factor by cytometric bead array. Results: In the trauma group, IL-8 was elevated in the CSF but not in the serum, while IL-6 was elevated in the serum but not in the CSF. IL-1 beta, associated with elevated IL-12, was also detected in the serum of three of 11 trauma patients but none of the nine controls. No other cytokines were consistently detected. Conclusions: This study raises the possibility that IL-8, acting in the CNS, plays a role in the postinjury syndrome. It is unclear as to the mechanism by which CNS IL-8 is produced in trauma but a physiological role is supported by the known ability of the CNS to produce IL-8 and the presence of receptors for its action in the CNS.