Expression of IL-6 activity in patients with acute ischemic stroke.

Cerebral ischemia initiates an inflammatory response in the brain and periphery. Inflammatory mechanisms, including IL-6, are suspected to play a role in arterial thrombogenesis. Their presence in the periphery is still controversial. The question arises as to whether IL-6 might directly contribute to cerebral infarct pathogenesis. IL-6 has several pro-inflammatory effects which may contribute to the induction and evolution of early inflammatory injury in the brain and its vasculature. The objective of this study was to test the hypothesis that there is a relationship between inflammation and the ischemic stroke measuring the levels of IL-6 in the blood of acute ischemic stroke patients. Plasma IL-6 was measured in 46 patients in the first 24 hours after acute ischemic stroke and in 98 controls matched for sex and age. Forty-five out of 46 acute ischemic stroke patients presented high IL-6 values. Fourteen out of 98 controls presented IL-6 values higher than normal. Mean level of circulating IL-6 was in acute ischemic stroke patients 26.5 +/- 2.3 pg/mL (range 6.4-161.3 pg/mL), significantly higher as compared to that in controls 3.9 +/- 1.5 pg/mL (range 2.3-5.9 pg/mL) [p < 0.0001, 95% CI (9.186 to 457.53)]. In our study, IL-6 levels were significantly elevated in the first 24 hours after ischemic stroke. This observation supports the hypothesis that IL-6 production is an inflammatory response to acute hypoxic-ischemic injury. IL-6 may serve as warning sign, because it increases early in inflammation.