Interleukin-6 in the Cerebrospinal Fluid After Perinatal Asphyxia is Related to Early and Late Neurological Manifestations

Objectives: To investigate if the concentration of interleukin-6 (IL-6) in the cerebrospinal fluid (CSF) is affected by perinatal asphyxia, and to examine the relation of IL-6 levels in the CSF to the severity of hypoxic-ischemic encephalopathy (HIE), to brain damage, and to the neurological outcome.

Methods: Asphyxiated term neonates were included. Cerebrospinal fluid IL-6 was measured by a sensitive enzyme-linked immunosorbent assay.

Results: Twenty neonates were studied: 3 had no HIE, 5 had stage 1, 6 had stage 2, and 6 had stage 3. CSF IL-6 levels (8 to 90 hours of life) were higher in neonates with HIE stage 3 (range, 65 to 2250 pg/mL) when compared with neonates with HIE stage 0 to 2 (<2 pg/mL in 12 neonates, 10 pg/mL in 1). According to neuroimaging techniques and/or pathological examination, 14 neonates were normal, and 5 showed signs of brain damage; 1 was not classified. CSF IL-6 levels were significantly higher in neonates with signs of brain damage. Finally, 5 neonates had adverse outcomes (4 died, 1 had cerebral palsy), 2 had mild motor impairment, and 13 had normal outcomes. CSF IL-6 levels were higher in neonates with adverse outcomes (range, 65 to 2250 pg/mL) compared with neonates with favorable outcomes.

Conclusion: The magnitude of IL-6 response in the CSF after perinatal asphyxia is related to the severity of neonatal HIE, to brain damage, and to the neurological outcome. Our results suggest that IL-6 might play a role in neonatal hypoxic-ischemic brain damage.