THE RELATIONSHIP OF SOLUBLE ADHESION MOLECULE CONCENTRATIONS IN SYSTEMIC AND JUGULAR VENOUS SERUM TO INJURY SEVERITY AND OUTCOME AFTER TRAUMATIC BRAIN INJURY

Adhesion molecules control the migration of leukocytes into tissue aft er injury. This may result in further cellular damage. We hypothesized that altered serum concentrations of soluble intercellular adhesion m olecule (sICAM)-1 and soluble L-selectin (sL-selectin) after traumatic brain injury would correlate with injury severity and neurological ou tcome. We investigated serum concentrations of sICAM-1 and sl-selectin in 22 patients with traumatic brain injury admitted to the intensive care unit. The Glasgow Coma Scale (GCS) score and Injury Severity Scor e were recorded. Paired arterial and jugular venous blood samples were taken on admission and 24, 48, and 96 h after injury. Mean systemic a nd jugular venous concentrations of sICAM-1 were normal on admission b ut became significantly increased by 96 h (P = 0.018). sl-selectin con centrations of injured patients were markedly below those of controls at all time points (P < 0.001). There were no significant differences between jugular venous and arterial concentrations of either sICAM-1 o r sl-selectin. Serum sICAM-1 was significantly related to neurological outcome (P < 0.001) and to the GCS score (P < 0.001). These changes i n adhesion molecule expression after acute brain injury may be importa nt in the pathophysiology of secondary injury. The highly significant relationship between serum sICAM-1 and neurological outcome suggests t hat the inflammatory response to injury may be detrimental. Drugs that antagonize the actions of the adhesion molecules may have a role in t herapy after traumatic brain injury. Implications: This observational study shows that there is a strong association between soluble interce llular adhesion molecule-1 in serum and poor neurological outcome afte r traumatic brain injury. This suggests that inflammation after brain injury may worsen the prognosis and that therapies directed against th is inflammation may prove useful.