Cerebrospinal IL-10 concentration is elevated in non-survivors as compared to survivors after severe traumatic brain injury.

OBJECTIVE: The intrathecal posttraumatic inflammation contributes to secondary brain damage as well as to the induction of neuroreparative mechanisms. In this context release of interleukin-10 (IL-10) has been reported to play a major role. However, initial IL-10 concentration in CSF remains incompletely characterized. Therefore, the aim was to analyze Il-10 in CSF and serum of patients early after TBI.
METHODS: For control, 10 volunteers receiving spinal puncture were enrolled. In patients with severe TBI (GCS<8 pts.), CSF and serum was drawn within 90+/-45 min after intraventricular catheter insertion (0 h), as well as 12 h, 24 h and 48 h after TBI. Albumin for assessing Blood-Brain-Barrier (BBB) function and IL-10 (IMMULITE, DPC Biermann, Bad Nauheim, Germany) were analyzed.
RESULTS: 23 patients were enrolled. 15 survived and 8 deceased within 24h. In controls, CSF IL-10 was below detection limit (<5 pg/ml). In contrast, IL-10 was elevated significantly in non-survivors at 0 h vs. survivors and controls (30+/-6 vs. 9+/-1 vs. <5 pg/mL). This was accompanied by a significant increase of serum IL-10 in both groups at 0 h vs. controls (survivors: 30+/-6 pg/mL, non-survivors: 48+/-8 pg/mL, controls: 10+/-7 pg/mL, p<0.001). Survivors revealed signs of a mild BBB dysfunction during the entire observation period. In contrast, non-survivors presented a severe BBB breakage.
CONCLUSIONS: We demonstrated an analysis of IL-10 CSF and serum concentration after TBI. These data support an intrathecal IL-10 synthesis. Although the significant increase of IL-10 might indicate a bad outcome of TBI, responsible mechanisms still have to be elucidated.