Objectives: To determine CSF levels of IL-6 following perinatal asphyxia, and to examine their relation to hypoxic-ischemic encephalopathy(HIE) and to outcome.

Methods: 20 neonates with perinatal asphyxia were studied. Early neonatal neurological status and outcome at 10.8±6.1 (m±sd) months were assessed. CSF IL-6 was measured by a sensitive ELISA (Helle M et al. J Immunol Methods 1991;138:47-56).

Results: 3 neonates had no HIE, 5 had stage 1, 6 stage 2, and 6 stage 3. CSF IL-6 levels (8 to 90 hours of life) were higher in neonates with HIE stage 3 (range 65 to 2250) compared to neonates with HIE stage 0 (< 2 pg/ml), stage 1 (< 2 pg/ml), and stage 2 (< 2 pg/ml in 5 neonates, 10 pg/ml in 1) (p<0.01). Five neonates had adverse outcome: 4 died, and 1 had cerebral palsy. 13 had normal outcome and 2 mild hyperreflexia. CSF IL-6 levels were higher in neonates with adverse outcome (range 65 to 2250) compared to neonates with favorable outcome (p<0.005).

Conclusion: These data provide the first evidence that CSF IL-6 levels are related to the severity of neonatal HIE and to the outcome. Our results suggest that CNS IL-6 is involved in the pathogenesis of human hypoxic-ischemic brain damage.