Serial measurement of interleukin-6, transforming growth factor-β, and S-100 protein in patients with acute stroke

Background and Purpose: Cytokine changes in patients with acute stroke have been insufficiently studied. The purpose of this study was to delineate the characteristics of serial changes of serum interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) in patients with cerebral infarction and intracerebral hemorrhage. Methods: We serially (within 24 hours, at day 3, and at day 7) measured the serum levels of IL-6 and TGF-β in 29 patients with acute stroke (10 with large cortical cerebral infarction, 9 with subcortical small infarction, and 10 with intracerebral hemorrhage). As an index of brain damage, S-100 protein was also measured. Twelve age-matched healthy subjects were tested as a control. Results: S-100 protein was detected in only 11 patients with large infarction or intracerebral hemorrhage. Its level peaked at day 3 in patients with infarction, whereas it peaked within 24 hours in those with intracerebral hemorrhage. The level of IL-6 was most markedly elevated at day 1, which tended to decrease thereafter. However, its level remained significantly elevated compared with that of the control group even at day 7. The level of TGF-β was significantly decreased at day 1 and day 3 and tended to return toward the control value thereafter. The levels of both cytokines were not significantly different among the three different stroke subtypes and were not correlated with the number of blood leukocytes and platelets. Conclusions: The alteration of IL-6 and TGF-β levels, which occurs rapidly after acute stroke regardless of the subtype, may reflect the changing immunological- inflammatory status of these patients and does not appear to reflect merely the consequence of the brain damage.