[Levels of interleukin-6 and tumor necrosis factor-alpha in the cerebrospinal fluid of full-term newborns with hypoxic-ischemic encephalopathy].

OBJECTIVE

To determine cerebrospinal fluid levels of interleukin-6 and tumor necrosis factor-alpha in full-term infants with hypoxic-ischemic encephalopathy, comparing with control infants.

METHODS

Controlled, prospective study, performed between July 1999 and October 2001 with two groups of full-term newborns: 20 controls with no sepsis and/or meningitis and Apgar score > or =9 at first and fifth minutes; and cases, 15 asphyxiated full-term newborns with Apgar < or =4 and < or =6 at first and fifth minutes, umbilical blood cord pH<7.20 and/or umbilical arterial blood lactate>3.0 mmol/L, and requiring positive pressure ventilation for at least 2 minutes after birth. Cerebrospinal fluid samples were collected within 48 hours of birth for determination of interleukin-6 and tumor necrosis factor-alpha by enzyme immunoassay.

RESULTS

Groups were similar concerning birthweight, gestational age, type of delivery and mean time required for cerebrospinal fluid sample collection. The samples were collected at mean with 17 hours of life. The medians cerebrospinal fluid levels in asphyxiated newborn infants were: 157.5 pg/ml for interleukin-6 and 14.7 pg/ml for tumor necrosis factor-alpha, significantly higher than the controls (interleukin-6: 4.1 pg/ml and tumor necrosis factor-alpha: 0.16 pg/ml).

CONCLUSIONS

Full-term newborns with hypoxic-ischemic encephalopathy present higher cerebrospinal fluid interleukin-6 and tumor necrosis factor-alpha levels than the controls, possibly because of the local cerebral production of these cytokines, especially tumor necrosis factor-alpha. These results support a recommendation for future studies with brain blockers of the actions of these cytokines for neuroprotective strategies.