Purpose: Proinflammatory and anti-inflammatory cytokines may play a pivotal role in cerebral inflammation, which is implicated in the development of brain injury. Systemic cytokine release is mediated by the sympathetic nervous system and catecholamines. The aim of this study was to investigate which parameters, among plasma levels of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor alpha (TNF-alpha) and the levels of the catecholamines, epinephrine and norepinephrine, contribute to the clinical outcome in acute stroke patients.
Methods: Thirty-seven acute stroke patients (ischemic, n = 19; hemorrhagic, n = 18) were enrolled. All of them were admitted to our hospital within 8 h after stroke onset. Neurological status was evaluated by a modified National Institute of Health Stroke Scale (mNIHSS) on admission and by a modified Rankin Scale (mRS) at 1 month. An mRS score of 3 or more at 1 month was considered to indicate poor outcome. Serum samples for the cytokine and catecholamine measurements were collected on admission. Plasma levels of IL-1beta, IL-6, IL-10, and TNF-alpha were determined by an enzyme-linked immunosorbent assay (ELISA) method and epinephrine and norepinephrine concentrations were determined by high-performance liquid chromatography with electrochemical detection (HPLC-EC).
Results: In the ischemic stroke patients, poor outcome was noted in 9 (47%). There were no significant differences in cytokine or catecholamine concentrations between patients with poor and good outcomes, and there was no association between clinical outcome and cytokine and catecholamine concentrations. In the hemorrhagic stroke patients, poor outcome was noted in 10 (56%). IL-6 and IL-10 levels were higher in patients with poor outcome. On logistic regression analysis, higher values of IL-6 were significantly associated with clinical outcome at 1 month (odds ratio [OR], 1.25; 95% confidence interval [CI], 1.02-1.54).
Conclusion: In ischemic stroke, plasma cytokines and catecholamines were not predictors of neurological outcome at 1 month. In hemorrhagic stroke, high levels of IL-6 in the early phase indicated a poor neurological outcome.