Interleukin-6 and interleukin-8 are elevated in the cerebrospinal fluid of infants exposed to chorioamnionitis.
The clinical or histologic diagnosis of chorioamnionitis has been associated with an increased risk of neuropathology and adverse neurologic outcomes in premature and term infants. Inflammatory cytokines have been implicated in the pathogenesis of these processes. The objective of this study was to determine whether exposure to chorioamnionitis and fetal inflammatory syndrome is associated with elevated concentrations of inflammatory cytokines (TNF-alpha, IL-6, and IL-8) in the CSF of term and preterm infants. Eighty-four mother/infant pairs were studied, 54 infants were premature. Twenty-eight showed signs of maternal (n = 14), or fetal (n = 14) inflammation based on placental pathology; mothers of 24 infants showed signs of clinical chorioamnionitis not confirmed by placental pathology and 32 infants were considered as 'controls' since they had only transient difficulty adjusting to extra-uterine life warranting evaluation for sepsis. The cytokine concentrations in the CSF were measured within 24 h of birth. When compared to the control group (IL-8 = 341 +/- 170 pg/ml and IL-6 = 7.4 +/- 1.8 pg/ml) significantly higher concentrations of IL-8 were detected in the CSF of infants exposed to clinical chorioamnionitis (1,854 +/- 878 pg/ml; p = 0.001) and maternal/fetal inflammation (1,754 +/- 787 pg/ml; p = 0.001) and of IL-6 in infants with maternal/fetal inflammation (47.6 +/- 45.1 pg/ml; p = 0.01). These results indicate that infants exposed to clinical chorioamnionitis, or inflammation in utero, experience at least a transient elevation in inflammatory cytokines in CSF.