A microdialysis method for the recovery of IL-1beta, IL-6 and nerve growth factor from human brain in vivo

Intracerebral microdialysis is used extensively as a research tool in the investigation of the neurochemical and metabolic changes that occur following acute brain injury. Microdialysis has enabled elucidation of intra-cerebral levels of substances such as lactate, pyruvate and glycerol but, as yet, has not been used effectively to recover macromolecules from the human brain. Traumatic brain injury is known to result in the generation of cytokines and neurotrophins into extracellular fluid compartment of the brain, with effects on neuronal damage and repair. We have developed a technique of in vivo sampling of the interstitial fluid of the brain of patients with severe head injuries which has allowed the measurement of IL-1beta, IL-6 and nerve growth factor. This report confirms the safety and effectiveness of this modified microdialysis method in the clinical setting of a neurological intensive care unit. The technique provides a timely addition to the armamentarium of the clinical scientist and will potentially lead to a greater understanding of neuroinflammation following acute traumatic brain injury.