Tumor necrosis factor alpha serum levels and inflammatory response in acute ischemic stroke patients

Experimental evidence indicates that tumor necrosis factor alpha (TNF-alpha) is involved in brain damage following ischemic injury. The present study was designed to monitor serum TNF-alpha levels in acute stroke patients and to correlate TNF-alpha levels with lesion size, neurological impairment and vascular risk factors. In 41 patients with ischemic stroke, serum TNF-alpha levels were serially measured by a solid enzyme amplified sensitivity immunoassay (EASIA) in the first 10 days after stroke onset. Serum fibrinogen and C-reactive protein (CRP), white blood cell (WBC) and neutrophil counts were determined on the same days to monitor acute phase response changes. Lesion size was calculated on computed tomograms by a computer-assisted procedure. Neurological impairment was evaluated on the Canadian Neurological Scale. Forty age-matched subjects were used as controls. Compared to baseline, TNF-alpha levels significantly increased during the study ( p=0.0001), peaking on day 7. Peak TNF-alpha levels did not correlate with neurological impairment or lesion size. Multivariate analysis showed that sex, age, vascular risk factors and infectious complications did not influence TNF-alpha levels. Fibrinogen, CRP, WBC and neutrophil concentrations increased, indicating an acute phase response occurred after stroke. In conclusion, serum TNF-alpha levels showed an early and prolonged increase after stroke onset, unrelated to lesion size, neurological impairment, age, sex, vascular risk factors or infectious complications. Serum increase of TNF-alpha may be explained as part of the acute phase response occurring in stroke patients.