NICU admission hypothermia, chorioamnionitis, and cytokines.

OBJECTIVE: To determine whether neonatal intensive care unit (NICU) admission hypothermia is associated with an intrauterine inflammatory response. METHODS: We analyzed a cohort of 309 very low birthweight infants to determine relationships between admission hypothermia, chorioamnionitis, and serum and cerebrospinal fluid (CSF) interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α. RESULTS: Admission hypothermia <36°C occurred in 72% of patients <26 weeks and 44% of patients ≥26 weeks gestational age. NICU admission hypothermia was not associated with histologic chorioamnionitis or with elevated serum cytokine concentrations. CSF IL-6 concentrations ≥6.3 pg/mL were associated with admission hypothermia in infants <26 weeks' gestation. Clinical chorioamnionitis was associated with a lower risk of admission hypothermia, while cesarean section delivery was associated with increased risk. CONCLUSIONS: NICU admission hypothermia is common among preterm infants and is not associated with the fetal inflammatory response syndrome. Hypothermia is less common in the setting of clinical chorioamnionitis and more common in cesarean section deliveries, identifying two groups in whom extra attention to appropriate thermoregulation is warranted.

Interleukin-6 and interleukin-8 are elevated in the cerebrospinal fluid of infants exposed to chorioamnionitis.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: These results indicate that infants exposed to clinical chorioamnionitis, or inflammation in utero, experience at least a transient elevation in inflammatory cytokines in CSF.

Inflammatory markers in intrauterine and fetal blood and cerebrospinal fluid compartments are associated with adverse pulmonary and neurologic outcomes in preterm infants.

Recent evidence strongly implicates the inflammatory response to intrauterine infection in the pathogenesis of neonatal brain and lung injury. We hypothesized that lung and brain injury in preterm infants occurs during a common developmental window of vulnerability as the result of an inflammatory response in different compartments. To determine whether inflammatory markers in these compartments are associated with bronchopulmonary dysplasia (BPD) or cranial ultrasound (CUS) abnormalities in infants <33 wk gestation age (GA) and <1501 g birth weight, we analyzed placental pathology and serum and cerebrospinal fluid (CSF) IL-6, IL-1beta, and tumor necrosis factor-alpha (TNF-alpha) concentrations in 276 infants. Logistic regressions were performed stratified by GA. Histologic chorioamnionitis was significantly associated with BPD in infants /=17 pg/mL was associated with an abnormal CUS in infants >28 wk GA (OR 3.36, p = 0.023) but not /=6.5 pg/mL and TNF-alpha >/=3 pg/mL were associated with abnormal CUS in infants /=28 wk GA. These data suggest that in infants