Increasing levels of TNFalpha are associated with increased brain perfusion.

OBJECTIVE

Recent reports of animal models have shown that growth factors have stimulating effect on brain perfusion via the development of blood vessels. However, studies on the effect of growth factors on brain perfusion in humans are lacking. The aim of our study was to prospectively investigate in humans the relation between growth factors and brain perfusion.

METHODS

We analyzed circulating levels of vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating growth factor (GM-CSF), tumor necrosis factor alpha (TNFalpha) and basic fibroblast growth factor (bFGF) in 121 consecutive patients (99 men and 22 women, age 58+/-10 years) who were enrolled in a prospective cohort study of patients with symptomatic atherosclerotic disease. In all patients regional cerebral blood flow (rCBF; in mL/min/100g) measurements were performed with arterial spin labeling magnetic resonance imaging. Cerebrovascular risk factors were assessed by means of a questionnaire and physical, ultrasonographic and laboratory examination.

RESULTS

Increasing levels of TNFalpha were significantly associated with a higher rCBF (beta=7.0; 95% confidence interval 0.7; 13.9), independent of the presence of cerebrovascular risk factors. No significant association was found for VEGF, GM-CSF and bFGF.

CONCLUSIONS

Increasing levels of TNFalpha are associated with increased rCBF, independent of the presence of cerebrovascular risk factors.