The level of interleukin-6 in acute ischemic stroke: effect on the rate of recovery in patients and on the severity of neurological defect

Abstract

Interleukin 6 (IL-6) plays an important role in the pathogenesis of ischemic stroke (IS), exerting a modulating effect on a number of processes that determine the outcome of this disease. Objective: to investigate the peripheral blood levels of IL-6 in patients in the acute period of different IS pathogenetic subtypes and its effect on recovery rates. Patients and methods. The study enrolled 155 patients (74 men and 81 women; mean age, 63.8 years). A control group consisted of 28 people without IS. Pathogenetic subtype II was established in accordance with the TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria on the basis of their clinical picture and the data of computed tomography or magnetic resonance imaging and ultrasonography of the main arteries of the head. The severity of a patient's condition and a focal neurological defect and the time course of clinical changes after stroke were determined using the National Institutes of Health Stroke Scale (NIHSS). An enzyme immunoassay (EIA) was used to measure IL-6 levels on days 1, 7, and 21 after onset of IS. An enzyme immunoassay (EIA) was used to measure IL-6 levels on days 1, 7, and 21 after onset of IS. Results. In the acute period of IS, there were significantly elevated levels of IL-6. The latter reached its highest values on day 7 in patients with the atherothrombotic pathogenetic subtype of IS. On day 7 of the study, the peak concentration of IL6 was typical for patients with all subtypes of IS, except for lacunar stroke. After its increase on day 1 of the study, the IL6 level in patients with lacunar stroke did not change significantly in all other periods. In acute IS, the concentration of IL-6 was significantly influenced by the following cardiovascular risk factors: hypercholesterolemia of days 1, 7 (p<0.01) and 21 (p<0.05), hypertension in day 1 (p<0.05), diabetes mellitus on days 1 and 7 (p<0.05), and coronary heart disease in all the study periods (p<0.01). The IL-6 concentration significantly correlated with the severity of neurological defect, but did not significantly affect the rate of recovery in the patient with acute IS. Conclusion. IL-6 was established to be of prognostic value for the outcome of acute IS on day 7. The rate of recovery can be used to identify targets for therapeutic intervention.

Keywords

• ischemic stroke
• interleukin-6
• risk factors
• toast criteria