Clinical Study

The Role and Mechanisms of IL-6, IL-8 and TNF-a for Regulating Cerebral Hemodynamics in Term Infants With Hypoxic-Ischemic Encephalopathy

  • Jing Liu
  • Ying Hai Cao
  • Hang Fan Meng
  • Ping Xiao Rong

Received Date: 13.08.2006 Accepted Date: 13.03.2007 J Turk Ger Gynecol Assoc 2007;8(1):63-66

OBJECTIVE

It is well known that cytokines play important role in the pathophysiologic mechanisms of neonatal hypoxic-ischemic encephalopathy (HIE). Cytokines can regulate the cerebral hemodynamics, however their mechanisms have been reported rarely. This study was to explore the role and the mechanisms of cytokines on regulating cerebral hemodynamics in neonates with HIE.

STUDY DESIGN

The levels of peripheral blood interleukin-6 (IL-6), interleukin-8(IL-8), tumor necrosis factor-alpha (TNF-α), and endothelin-1(ET-1), calcitonin gene-related peptide (cGRP) in 30 hypoxic-ischemic encephalopathic and 30 healthy neonates were detected on the1st day of life using radioimmunoassay. And hemodynamic parameters of middle cerebral artery including peak systolic flow velocity (PSFV, cm/s), end-diastolic flow velocity (EDFV, cm/s),time-averaged mean velocity(TMFV, cm/s), pulsatility index (PI) and resistance index (RI) in both groups were measured by pulsed Doppler ultrasound after the blood samples had been collected immediately.

RESULTS

The results showed in infants with hypoxic-ischemic encephalopathy, the plasma levels of IL-8 and TNF-α were increased while the serum levels of IL-6 were decreased, which were correlated with disturbed cerebral hemodynamics and the changes of plasma levels ET-1 and cGRP. Linear correlation analysis showed RI was positively correlated with IL-8 (r=0.80; p<0.01) and TNF-α (r=0.72; p<0.01) while negatively correlated with IL-6 (r=-0.61; p<0.01). Furthermore, IL-8 and TNF-α were positively correlated with ET-1 (r=0.61; 0.72, respectively, p<0.01) and negatively correlated with cGRP (r=-0.51; -0.63, respectively, p<0.01). On the contrary, IL-6 was negatively correlated with ET-1 (r =-0.54; p<0.01) and positively correlated with cGRP (r =0.52; p<0.01).

CONCLUSION

The results of this study showed that the changes of plasma levels of IL-6, L-8 and TNF-α in neonatal hypoxic-ischemic encephalopathy may regulate cerebral hemodynamics by regulating the changes of ET-1 and cGRP so as to playing an important role in the pathophysiologic mechanisms.

Keywords: newborn, hypoxic-ischemic encephalopathy, cerebral hemodynamics, interleukin-6, interleukin-8, tumor necrosis factor-alpha, endothelin-1, calcitonin gene-related peptide