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Just another article. Please read the whole thing. What I have copied is about 1/3 down.

http://www.emedicine.com/neuro/topic602.htm

IL-6 in clinical stroke

Several clinical studies in patients with stroke have found an association between CSF and plasma IL-6 levels and infarct size and neurologic outcome. Some of these studies have yielded conflicting results.

Fassbender et al (1994) found that plasma levels of IL-6 showed a significant increase within the first few hours following stroke onset, peaking at 10 hours. This increased level of IL-6 significantly correlated with the volume of the brain lesion and was associated with a poor functional neurologic outcome. In contrast, serum levels of IL-1b and TNFa did not increase.

Different results were obtained by Tarkowski et al (1995). In this study, CSF levels of IL-6 were elevated significantly by day 2 and were correlated with the volume of infarct observed; serum levels of IL-6 did not correlate with the size of brain lesion. This study did not find any measurable levels of plasma IL-1b. Finally, Kim et al (1996) measured IL-6 levels in 29 patients with acute stroke. They found the level of IL-6 to be highest (49±16 pg/mL) at 24 hours after onset, remaining high (14±4 pg/mL) for at least 7 days.

The role of cytokines in clinical stroke also has been investigated. Plasma levels in vivo of IL-6 and the naturally occurring IL-1ra were measured using ELISA in 50 patients with acute stroke (4±2 days after onset) and in 20 age-matched healthy controls.

Levels of both IL-6 and IL-1ra were significantly higher in the stroke population (4.6±4.2 pg/mL and 354±270 pg/mL, respectively) than in controls (1.0±0.9 pg/mL and 139±113 pg/mL). The levels of both cytokines were significantly higher in patients who had infarcts measuring more than 3 cm on CT scans. We also found that the level of IL-6 is elevated not only in the acute stroke period, but it remains elevated for up to a year (compared to controls) upon longitudinal follow-up (Coull, 1993).

The acute IL-6 elevation and its ability to predict neurologic recovery from stroke has been investigated. In this study, plasma levels of IL-6, fibrinogen, and albumin along with white blood cell (WBC) count were measured within 4±2 days of onset in 131 patients with stroke. Standard clinical predictors of outcome also were obtained, including neurologic assessments and head CT infarct sizes.

Peak levels of IL-6 were correlated significantly (r=0.18) with 6-month outcome as assessed by the Glasgow Outcome Scale. Taken together, the acute-phase response variables strongly predicted 6-month recovery (R2=0.31) and were nearly as strong a predictor as the standard clinical predictors (R2=0.38). Recent clinical studies have confirmed these findings and found that IL-6 values strongly correlated with C reactive protein (Smith et al, 2004). Acalovschi et al (2003) recently confirmed the robust elevation of serum IL-6 post clinical stroke but found that the soluble receptors (antagonists) for IL-6 were downregulated. These clinical results suggest that the acute-phase response, in particular IL-6, is strongly associated with acute ischemic stroke; the acute-phase response also appears to be correlated with initial infarct size and degree of long-term recovery.

Cytokines - Conclusions

Taken together, the aforementioned observations strongly suggest that the