CSF cytokine levels in preterm infants may reflect systemic inflammation and are independent of gestation

Background

Among preterm infants, high concentrations of inflammatory mediators in cerebrospinal fluid (CSF) are associated with poor outcome. Previous studies have not indicated whether CSF concentrations of inflammatory mediators are associated with important confounders such as gestational age.

Aims

To examine associations between CSF concentrations of inflammatory mediators and gestational age, maternal features suggestive of inflammation, characteristics of the CSF sample or the presence of a systemic inflammatory response.

Study design and subjects

Aliquots of CSF obtained during routine investigation of potential sepsis among infants born before 35 weeks gestation were assayed for 17 mediators of inflammation using a fluorescent multi-bead analyser. Other information was collected from routine clinical records.

Results

39 infants were assessed. CSF levels of mediators of inflammation were not correlated with gestational age. CSF red blood cell counts were correlated with CSF concentrations of IL-6, GM-CSF and IL-17 (each p < 0.003). CSF lactate was correlated with CSF concentrations of IL-1β, IL-6, GM-CSF, G-CSF, IFN-γ and MIP-1β. CSF concentrations of IL-1β, IL-6, G-CSF, TNF-α and IFN-γ were higher in infants with a raised CRP within 24 h of delivery (each p < 0.003).

Conclusions

CSF concentrations of inflammatory mediators most probably reflect inflammatory pathologies and are not influenced by gestational age. They may also, however, reflect contamination with blood or systemic inflammation. CSF concentrations of inflammatory mediators may not provide a specific indicator of CNS inflammation.