Relationship between cytokine levels in serum and cerebrospinal fluid and brain injury in preterm infant with intrauterine infection

Abstract

Objective To evaluate the relationship between the cytokine levels in the serum and cerebrospinal fluid and the brain injury in preterm infants. Methods From August of 2012 to August of 2013, 51 preterm infants were included and 46 infants were survived.All of them were born at the Maternal and Child Hospital of Hubei Pro-vince, with GA≤32 weeks and high risk factors of intrauterine infection and suffering from early onset sepsis.According to the screening findings of cerebral ultrasound and/or MRI, the infants were divided into normal group(n=28) and abnormal groups(n=18) with intracranial hemorrhage or white matter damage.The levels of interleukin(IL)-6, IL-1β and tumor necrosis factor-α(TNF-α) in the serum within 12 hours after birth and in cerebrospinal fluid within 72 hours after birth were investigated.The differences in cytokines between two groups were compared with t-test and Chi-square test, and high risk factors of brain injury were analyzed by Logistic regression models. Results The abnormal group had higher incidence of clinical maternal chorioamnionitis[44.44%(8/18 cases) vs 14.29%(4/28 cases), χ2=5.168, P=0.038] and higher white blood cell count[(11.51±9.03)×109/L vs(6.95±5.64)×109/L, t=-2.107, P=0.041]. In the abnormal group, the levels of serum IL-6 [(44.83±16.31) ng/L], and IL-6, IL-1β and TNF-α in cerebrospinal fluid [(51.85±15.65) ng/L, (11.95±2.58) ng/L and(193.11±67.25) ng/L] were higher than those in the normal group[(36.83±8.76) ng/L, (42.56±12.89) ng/L, (10.26±2.91) ng/L and(160.56±29.02) ng/L, respectively] with the statistical difference(t=-2.687, -2.250, 0.269, -2.243, P=0.010, 0.029, 0.044, 0.030). Maternal chorioamnionitis, higher serum TNF-α and cerebrospinal fluid IL-6 were high risk factors for brain injury(P=0.014, 0.031, 0.047). Conclusion Increased systemic and cerebrospinal fluid cytokine levels are possibly related to the preterm brain injury when intrauterine infection occurred. Key words: Intrauterine infection; Chorioamnionitis; Cytokine; Preterm brain injury; Preterm, infant