567 - Inflammatory Biomarker Profiles in Premature Infants with Potential Prenatal or Postnatal Infection

Poster Number: 567
Publication Number: 567.427

Jordan Ewald, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Baiba Steinbrekera, University of South Dakota, Sanford School of Medicine, Sioux Falls, SD, United States; Jennifer Bermick, University of Iowa, Iowa City, IA, United States; Karen Johnson, University of Iowa, Iowa City, IA, United States; Tarah Colaizy, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA, United States; Robert Roghair, University of Iowa Stead Family Children's Hospital, Iowa City, IA, United States

Background: Preterm delivery can be precipitated by infection, and preterm infants are at heightened risk of postnatal infection. Little is known about the ontogeny of inflammatory biomarkers in extremely preterm infants.

Objective: We aim to further the knowledge of neonatal biomarker patterns by analyzing levels of three potential biomarkers in context of the infant demographics and infection status. We hypothesized that presumed antenatal infection (chorioamnionitis or spontaneous preterm labor) and postnatal clinical sepsis would be associated with unique biomarker signatures, and those patterns would be influenced by the degree of prematurity.

Design/Methods: Venous blood was collected daily for the first week and weekly for up to 14 additional weeks from 142 neonates prospectively enrolled into gestational age windows of 22-25, 26-29 or 30-32 weeks. A custom magnetic bead array was utilized to measure monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6). C-reactive protein (CRP) levels were obtained from the electronic medical record.

Results: 90 infants had presumed prenatal infection and 63 were diagnosed with postnatal sepsis. Biomarkers fell quickly over the first week and did not differ across gestational age cohorts. By multivariate analysis, prenatal infection was associated with MCP-1 and CRP while postnatal infection was associated with IL-6 and CRP elevation. Infants with isolated postnatal sepsis had increased IL-6 on day 2 (2826 versus 70 pg/ml, P< 0.001) and increased CRP on day 3 (7.2 versus 1.0 mg/dl, P< 0.01).Conclusion(s): Postnatal clinical sepsis is associated with increased IL-6 and CRP values, independent of the degree of prematurity. Temporally, in those with isolated postnatal concern for infection, IL-6 increases before CRP, emphasizing a potential role for expanded biomarker screening if antibiotics are initially avoided in infants born for maternal indications.
Table 1Plasma MCP-1, IL-6 and CRP levels were compared by one-way ANOVA. Factors that were significant on univariate analysis (chronologic age or prenatal infection for MCP-1, chronologic age or postnatal infection for IL-6 and prenatal or postnatal infection for CRP) were contrasted by two-way ANOVA with the Holm-Sidak Test for multiple comparisons. Data are presented as mean +/- SEM with significance indicated as *P < 0.05 or **P < 0.01
Figure 1MCP-1 and IL-6 levels from birth to postnatal day 7. Compared to neonates born without concern for prenatal infection (A, white bars), neonates delivered with clinical concern for prenatal infection (A, gray bars) had reduced plasma MCP-1 on day 2. Compared to neonates without postnatal sepsis (B, white bars), neonates diagnosed with postnatal sepsis (B, gray bars) have increased plasma IL-6 on day 0 and day 1. *P < 0.05