Serum interleukin-6 soluble receptor in relation to interleukin-6 in stroke patients

Cerebral ischemia triggers interleukin-6 (IL-6) release into blood. IL-6 is a key mediator of acute phase reaction. Markers of acute phase reaction (C-reactive protein, fibrinogen, fever) have been linked to poor prognosis in stroke patients. Interleukin-6 soluble receptor (sIL-6R) can potentiate IL-6 pro-inflammatory activity. The aim of this study was to investigate the relationship between IL-6 and sIL-6R in stroke patients. Serum cytokine levels were measured in 18 stroke patients and 13 controls using the ELISA method. On the second day of stroke, IL-6 levels were significantly higher in stroke patients than in controls; sIL-6R levels did not differ significantly between groups. Three months after stroke, IL-6 levels did not differ significantly between groups; sIL-6R levels were significantly decreased in stroke patients when compared with that in controls and with levels in acute phase of stroke. Decreased sIL-6R early after stroke might reflect a regulatory mechanism attenuating inflammatory response.