Serum IL-6, IL-8 and IL-10 levels in multiple trauma compared to traumatic brain injury and combined trauma

Background: In recent studies, the role of cytokines in traumatic brain injury (TBI) has been identified and the intrathecal origin of cytokines demonstrated. The question, however, whether or not there is any difference in serum cytokines between TBI, multiple trauma (MT) and the combination of both (MT with TBI) which may significantly contribute to the final outcome, has not been fully examined yet. Patients and Methods: In a prospective study three different groups of trauma patients were monitored for serum cytokine levels over a 7-day period, multiple organ dysfunction (MOD) and final outcome. The patients eligible for this study must have sustained either an isolated traumatic brain injury (TBI), or multiple trauma (MT) without TBI, or a multiple trauma in combination with TBI (MT+TBI). Results: In patients with isolated TBI (n = 40, cranial Abbreviated Injury Score [AIS_head] = 4.4 + O.8, total Injury Severity Score [ISS] = 17.1 ± 5.1), serum interleukin- (IL-)6 levels ranged between 150 and 200 pg/ml within the first 48 h followed by a constant decline (< 100 pg/ml) over the 7-day study period. By contrast, serum IL-6 levels of multiply injured patients (n = 10, AIS_head = 1.0 ± 1.2, total ISS = 29.9 ± 5.2) were significantly (p < 0.05) increased (range 350-400 pg/ml) after trauma, also followed by a constant decline. In patients suffering from MT including TBI (n = 44, AIS_head = 4.1 ± 0.9, total ISS = 31.8 ± 5.8), serum IL-6 levels were also significantly (P < 0.05) higher after trauma compared to TBI patients, but not significantly different from MT patients without TBI. IL-8 and IL-10 serum levels demonstrated a similar pattern, with low cytokine serum levels in the TBI group but significantly high serum levels in both MT groups. The multiple organ dysfunction (MOD) score of Marshall et al revealed no significant change in the TBI group over the 7-day period. In MT patients the MOD score deteriorated transiently around day 3, whereas in the combined trauma group the MOD score was elevated over the entire study period compared to both other trauma groups. Mortality was 27.5% in TBI patients, o in MT, and 52.3% in combined trauma. Conclusion: TBI alone does not result in a significant systemic inflammatory response, whereas the combination of TBI and MT seems to enhance the inflammatory reaction ending in a higher MOD incidence and MOD-related mortality as compared to MT without TBI.