Histologic chorioamnionitis is associated with reduced risk of late-onset sepsis in preterm infants

Late Neonatal Sepsis in Very-low-birth-weight Premature Newborns Is Associated With Alterations in Neurodevelopment at Twenty-five Months of Age

AIM

To evaluate the impact of late-onset sepsis (LOS) on the neurodevelopment of very-low-birth-weight (VLBW) premature infants.

METHODS

This is a retrospective cohort study of VLBW premature infants. The Mental Development Index (MDI) was determined for a population of 546 VLBW infants, at 14 and 25 months of age, and evaluated using the Bayley test. A history of meningitis or early neonatal sepsis was considered an exclusion criterion. The study parameters analyzed included perinatal variables, the development of neonatal comorbidities and a history of LOS. Multivariate linear regression and multinomial logistic regression analyses were performed.

RESULTS

LOS was observed in 115 newborns, among whom microbiological testing showed that 65.0% presented Gram-positive bacteria, with Staphylococcus epidermidis being responsible for 55.4%. There was a significant association between the 25-month MDI and a history of LOS. This represents a decrease of 7.9 points in the MDI evaluation of newborns with a history of LOS. The latter history is also associated with the following neurodevelopmental alternations: mild motor disorders [odds ratio (OR): 2.75; 95% confidence intervals (CI): 1.07-7.05], moderate cognitive delay (OR: 3.07; 95% CI: 1.17-8.00) and cerebral palsy (OR: 2.41; 95% CI: 1.09-5.35).

CONCLUSIONS

In our study cohort, LOS was associated with alterations in neurodevelopment, including reduced MDI, together with motor and cognitive disorders and cerebral palsy. To improve neurodevelopmental outcomes in this group of newborns, neonatal intensive care unit personnel should focus attention on preventing hospital-acquired infections.

[Advances in clinical management of neonatal sepsis]

Neonatal sepsis, as a significant cause of various complications and adverse outcomes in neonates, remains a serious health burden both domestically and internationally. Strategies such as antibiotic prophylaxis during delivery, the utilization of early-onset sepsis risk calculators, and quality improvement initiatives in neonatal wards are beneficial in alleviating the disease burden of neonatal sepsis. This paper provides a review of the epidemiology, risk factors, and recent advances in clinical management of neonatal sepsis.

Immunophenotypes of Newborns From SARS-CoV-2-infected Mothers

BACKGROUND

Little is known about the neonatal immunologic response to a maternal SARS-CoV-2 infection present during childbirth. Here we analyze a cohort of 75 neonates from SARS-CoV-2-infected mothers.

METHODS

The SARS-CoV-2 infection status was laboratory assessed by real-time reverse transcription polymerase chain reaction on nasopharyngeal swabs (NPS) in both mothers during childbirth and neonates within 24 hours of life. Immunophenotypes of peripheral blood mononucleated cells and SARS-CoV-2 antispike IgA, IgM and IgG of the newborns were recorded. Ten (13.3%) of 75 neonates had positive NPS for SARS-CoV-2; 17 of 75 (23%) were SARS-CoV-2-IgG seropositive, of which one with positive NPS. All the newborns resulted seronegative for SARS-CoV-2 IgA and IgM and were asymptomatic. Our cohort of newborns was divided into groups according to IgG seropositivity (IgG+/-) and NPS results (NPS+/-).

RESULTS

The count and proportion of lymphocyte subsets (evaluated measuring CD3, CD4, CD8 and CD19 markers) and of natural killer cells (evaluated by measuring the CD3-/CD16+/CD56+ subset) were all in the normal range, with no statistical differences among groups. We found a significant expansion of the T cell (CD3+) subset in the IgG+ group interpreted as the result of immune effects triggered by trained immunity in these newborns, but a decrease in CD4+ T cells for NPS+ neonates. It is therefore difficult to conclude that the decrease in CD4 can certainly be caused by an infection.

CONCLUSIONS

A maternal SARS-CoV-2 infection resulted in an expansive effect of CD3+ T cells in IgG+ newborns; nonetheless, it seems not to affect structural and functional development of the newborn immune system.

TRAINED IMMUNITY: A POTENTIAL APPROACH FOR IMPROVING HOST IMMUNITY IN NEONATAL SEPSIS

ABSTRACT

Sepsis, a dysregulated host immune response to infection, is one of the leading causes of neonatal mortality worldwide. Improved understanding of the perinatal immune system is critical to improve therapies to both term and preterm neonates at increased risk of sepsis. Our narrative outlines the known and unknown aspects of the human immune system through both the immune tolerant in utero period and the rapidly changing antigen-rich period after birth. We will highlight the key differences in innate and adaptive immunity noted through these developmental stages and how the unique immune phenotype in early life contributes to the elevated risk of overwhelming infection and dysregulated immune responses to infection upon exposure to external antigens shortly after birth. Given an initial dependence on neonatal innate immune host responses, we will discuss the concept of innate immune memory, or "trained immunity," and describe several potential immune modulators, which show promise in altering the dysregulated immune response in newborns and improving resilience to sepsis.

Chorioamnionitis-exposure alters serum cytokine trends in premature neonates

OBJECTIVES

Determine if chronologic age and/or chorioamnionitis exposure alter normal serum cytokine and chemokine levels in uninfected preterm neonates during their initial NICU stay.

STUDY DESIGN

A 7-plex immunoassay measured levels of serum IL-1β, IL-6, IL-8, IL-10, TNF-α, CCL2, and CCL3 longitudinally from chorioamnionitis-exposed and unexposed preterm neonates under 33 weeks' gestation.

RESULTS

Chorioamnionitis-exposed and unexposed preterm neonates demonstrated differences in the trends of IL-1β, IL-6, IL-8, IL-10, TNF-α, and CCL2 over the first month of life. The unexposed neonates demonstrated elevated levels of these inflammatory markers in the first two weeks of life with a decrease by the third week of life, while the chorioamnionitis-exposed neonates demonstrated differences over time without a predictable pattern. Chorioamnionitis-exposed and unexposed neonates demonstrated altered IL-10 and TNF-α trajectories over the first twelve weeks of life.

CONCLUSION

Chorioamnionitis induces a state of immune dysregulation in preterm neonates that persists beyond the immediate neonatal period.

Actualidad en corioamnionitis

La corioamnionitis se ha relacionados con desenlaces desfavorables en el período prenatal y neonatal (abortos, parto pretérmino, sepsis neonatal, entre otros), además de implicaciones a largo plazo en la infancia, tales como alteraciones en el coeficiente intelectual. Por esta razón es de vital importancia el diagnóstico histopatológico oportuno. En este artículo se revisará el abordaje histopatológico de la corioamnionitis, su estadificación e implicaciones clínicas.

Diagnosis of Neonatal Sepsis: The Role of Inflammatory Markers

This is a narrative review on the role of biomarkers in the diagnosis of neonatal sepsis. We describe the difficulties to obtain standardized definitions in neonatal sepsis and discuss the limitations of published evidence of cut-off values and their sensitivities and specificities. Maternal risk factors influence the results of inflammatory markers as do gestational age, the time of sampling, the use of either cord blood or neonatal peripheral blood, and some non-infectious causes. Current evidence suggests that the use of promising diagnostic markers such as CD11b, CD64, IL-6, IL-8, PCT, and CRP, either alone or in combination, might enable clinicians discontinuing antibiotics confidently within 24-48 h. However, none of the current diagnostic markers is sensitive and specific enough to support the decision of withholding antibiotic treatment without considering clinical findings. It therefore seems to be justified that antibiotics are often initiated in ill term and especially preterm infants. Early markers like IL-6 and later markers like CRP are helpful in the diagnosis of neonatal sepsis considering the clinical aspect of the neonate, the gestational age, maternal risk factors and the time (age of the neonate regarding early-onset sepsis) of blood sampling.

Exposure to intrauterine inflammation and late-onset sepsis in very preterm infants

BACKGROUND

Late-onset sepsis is an important cause of mortality and morbidity in preterm infants. As these infants rely mostly on their innate immune system to fight off infection, enhancing this immune system by appropriate stimuli may prevent late-onset sepsis. However, it remains unclear which stimuli can enhance the neonatal immune system. This study aims to investigate the influence of intrauterine inflammation on late-onset sepsis.

METHODS

This is a retrospective cohort study in a Neonatal Intensive Care Unit in the Netherlands. Between 2005 and 2016, 1014 infants with ≤32 weeks gestational age and/or with a birth weight ≤1500 g were included. Intrauterine inflammation was subdivided into histological chorioamnionitis, fetal inflammatory response, and funisitis. Logistic and Cox regression analyses were performed to investigate the influence of intrauterine inflammation on late-onset sepsis.

RESULTS

Thirty-six percent of the included infants developed late-onset sepsis; 24% of placentas showed intrauterine inflammation. Late-onset sepsis incidence did not differ between infants with or without exposure to intrauterine inflammation after adjustment for gestational age (histological chorioamnionitis aHR 0.928 [CI: 0.727-1.185], p = 0.551; fetal inflammatory response aHR 1.011 [CI: 0.793-1.288], p = 0.930); funisitis aHR 0.965 [CI: 0.738-1.263], p = 0.797).

CONCLUSIONS

Late-onset sepsis in very preterm infants seems not to be associated with intrauterine inflammation.

IMPACT

Intrauterine inflammation is not protective of developing late-onset sepsis in premature infants. A large cohort study on the effect of intrauterine inflammation on neonatal outcome. This study adds to existing knowledge on finding appropriate stimuli to enhance the immune system of premature infants to improve neonatal outcome.

Clinical chorioamnionitis and histologic placental inflammation: association with early-neonatal sepsis

OBJECTIVE

Chorioamnionitis and fetal inflammatory response syndrome (FIRS) are significant risk factors for early onset sepsis (EOS). Recently, the use "Intrauterine Inflammation or Infection or both" or triple I has been proposed, classifying cases into an isolated maternal fever, suspected triple I, or confirmed chorioamnionitis. Evidence suggests that the association between suspected chorioamnionitis and confirmed histological chorioamnionitis (HCA) is not consistent, as well as the impact of HCA on the development of EOS.We aimed to evaluate the association between suspected chorioamnionitis and HCA, the impact of HCA on EOS, and the effect of antepartum antibiotic prophylaxis on EOS.

METHODS

We retrospectively reviewed the medical records of all infants admitted to our institution, between 2017 and 2018, with a diagnosis of chorioamnionitis. We recorded the clinical evidence of chorioamnionitis, the histologic report of the placenta, the maternal and neonatal data, the neonatal inflammatory markers including C-reactive protein (CRP), and the incidence of EOS. The impact of antepartum antibiotic prophylaxis on the infants' CRP and EOS was calculated, and the logistic regression model was performed to estimate the association of confirmed HCA with EOS, while controlling for FIRS stage, gestation age, birth weight, maternal fever, foul-smelling amniotic fluid, and prolonged rupture of membranes.

RESULTS

During the study period, a total of 266 infants were identified; 81 (30%) infants had a confirmed HCA (HCA-present cases), and 185 (70%) infants were diagnosed with suspected triple I (HCA-absent cases). Antepartum antibiotics had been commenced in a significantly higher proportion in HCA-present cases (46%) in comparison to 14% of HCA-absent cases (p < .001). HCA-present infants were of significantly lower gestation (31.6 ± 4weeks versus 33.3 ± 4weeks, p = .004), and birth weight (1826 ± 840 g versus 2092 ± 849 g, p = .019), they had a significantly higher rate of clinical symptoms (31% versus 6%, p < .001), and a higher CRP at birth and 24 h (1.4 ± 1.5 mg/dL versus 0.3 ± 0.2 mg/dL, p < .001, and 2.1 ± 2.3 mg/dL versus 0.4 ± 0.6 mg/dL, p < .001, respectively). All HCA-present cases had evidence of FIRS; 43% were stage I, 25% stage II, and 32% were FIRS stage III. A significantly higher proportion of HCA-present infants were diagnosed with EOS (46% as compared to 6%, p < .001). The antepartum antibiotic administration was related to a significantly lower CRP at birth and 24 h only in HCA-present cases, albeit not with any reduction ιn EOS incidence. HCA was significantly associated with EOS (RR 3.18, 95% CI 2.81-5.18, p < .001). After adjusting for perinatal factors, the presence of HCA (OR 7.89, 95% CI 1.19-23.34, p = .032) and an advanced FIRS stage (OR 10.35, 95% CI 4.23-25.32, p < .001) were significantly associated with EOS.

CONCLUSIONS

Amongst infants with suspected chorioamnionitis, the diagnosis is partially supported by histological confirmation, and that is more prominent in pregnancies of a lower gestation. The presence of HCA and an advanced FIRS stage predispose to an increased risk of EOS after adjusting for other perinatal and neonatal factors. The antepartum prophylaxis against intra-amniotic infection was related to a significantly lower CRP in HCA-present cases.

Neurodevelopmental Outcomes at 18-24 Months of Corrected Age in Very Low Birth Weight Infants with Late-onset Sepsis

BACKGROUND

Preterm infants are prone to sepsis owing to their immature innate immunity and prolonged hospitalization. We aimed to evaluate the association between late-onset sepsis (LOS) during hospitalization and neurodevelopmental delay at 18-24 months of corrected age in very low birth weight infants (VLBWIs), and to ascertain this association when adjusted for perinatal risk factors.

METHODS

This is a population-based study of VLBWIs born at 23-32 weeks of gestation between January 2014 and December 2017 who were enrolled in the Korean Neonatal Network. Bayley scales of infant development were evaluated at 18-24 months of corrected age in 2,098 infants. To test for LOS as a risk factor for neurodevelopmental delay, multiple logistic regression was used and adjusted for parental education status and clinical variables.

RESULTS

Blood culture positive LOS was identified in 419 (20.0%) infants. Cognitive and motor delays were found in 392 (18.7%) and 347 (16.5%) infants, respectively. When multivariate analysis was performed, LOS had a significant association with cognitive delay (odds ratio, 1.48; 95% confidence interval, 1.02-2.16), but no association with motor delay in VLBWIs. Both delays were significantly more frequent in cases of intraventricular hemorrhage (IVH) ≥ grade 3, periventricular leukomalacia (PVL), and intrauterine growth restriction (IUGR) and duration of mechanical ventilation. Male sex and necrotizing enterocolitis ≥ grade 2 had an effect on motor delay, whereas paternal college graduation affected cognitive delay.

CONCLUSION

In VLBWIs with LOS, there is a heightened risk of cognitive delays at 18-24 months of corrected age. Brain injury, such as severe IVH and PVL, duration of mechanical ventilation, and IUGR, were also associated with cognitive and motor delays.

Chorioamnionitis and Risk for Maternal and Neonatal Sepsis: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate the risk of maternal and neonatal sepsis associated with chorioamnionitis.

DATA SOURCES

PubMed, BIOSIS, and ClinicalTrials.gov databases were systematically searched for full-text articles in English from inception until May 11, 2020.

METHODS OF STUDY SELECTION

We screened 1,251 studies. Randomized controlled trials, case-control, or cohort studies quantifying a relationship between chorioamnionitis and sepsis in mothers (postpartum) or neonates born at greater than 22 weeks of gestation were eligible. Studies were grouped for meta-analyses according to exposures of histologic or clinical chorioamnionitis and outcomes of maternal or neonatal sepsis.

TABULATION, INTEGRATION, AND RESULTS

One hundred three studies were included, and 55 met criteria for meta-analysis (39 studies of preterm neonates, 10 studies of general populations of preterm and term neonates, and six studies of late preterm and term neonates). Study details and quantitative data were abstracted. Random-effects models were used to generate pooled odds ratios (ORs); most studies only reported unadjusted results. Histologic chorioamnionitis was associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 4.42 [95% CI 2.68-7.29] and 5.88 [95% CI 3.68-9.41], respectively). Clinical chorioamnionitis was also associated with confirmed and any early-onset neonatal sepsis (unadjusted pooled ORs 6.82 [95% CI 4.93-9.45] and 3.90 [95% CI 2.74-5.55], respectively). Additionally, histologic and clinical chorioamnionitis were each associated with higher odds of late-onset sepsis in preterm neonates. Confirmed sepsis incidence was 7% (early-onset) and 22% (late-onset) for histologic and 6% (early-onset) and 26% (late-onset) for clinical chorioamnionitis-exposed neonates. Three studies evaluated chorioamnionitis and maternal sepsis and were inconclusive.

CONCLUSION

Both histologic and clinical chorioamnionitis were associated with early- and late-onset sepsis in neonates. Overall, our findings support current guidelines for preventative neonatal care. There was insufficient evidence to determine the association between chorioamnionitis and maternal sepsis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42020156812.

Human Newborn Monocytes Demonstrate Distinct BCG-Induced Primary and Trained Innate Cytokine Production and Metabolic Activation In Vitro

Background

Newborns exhibit distinct immune responses and are at high risk of infection. Neonatal immunization with BCG, the live attenuated vaccine against tuberculosis (TB), is associated with broad protection against a range of unrelated pathogens, possibly reflecting vaccine-induced training of innate immune cells ("innate memory"). However, little is known regarding the impact of age on BCG-induced innate responses.

Objective

Establish an age-specific human monocyte in vitro training platform to characterize and compare BCG-induced primary and memory cytokine responses and immunometabolic shifts.

Design/Methods

Human neonatal and adult CD33-selected monocytes were stimulated for 24h with RPMI (control) or BCG (Danish strain) in 10% autologous serum, washed and cultured for 5 additional days, prior to re-stimulation with the TLR4 agonist LPS for another 24h. Supernatants were collected at Day 1 (D1) to measure primary innate responses and at Day 7 (D7) to assess memory innate responses by ELISA and multiplex cytokine and chemokine assays. Lactate, a signature metabolite increased during trained immunity, was measured by colorimetric assay.

Results

Cytokine production by human monocytes differed significantly by age at D1 (primary, BCG 1:750 and 1:100 vol/vol, p<0.0001) and D7 (innate memory response, BCG 1:100 vol/vol, p<0.05). Compared to RPMI control, newborn monocytes demonstrated greater TNF (1:100, 1:10 vol/vol, p<0.01) and IL-12p40 (1:100 vol/vol, p<0.05) production than adult monocytes (1:100, p<0.05). At D7, while BCG-trained adult monocytes, as previously reported, demonstrated enhanced LPS-induced TNF production, BCG-trained newborn monocytes demonstrated tolerization, as evidenced by significantly diminished subsequent LPS-induced TNF (RPMI vs. BCG 1:10, p <0.01), IL-10 and CCL5 production (p<0.05). With the exception of IL-1RA production by newborn monocytes, BCG-induced monocyte production of D1 cytokines/chemokines was inversely correlated with D7 LPS-induced TNF in both age groups (p<0.0001). Compared to BCG-trained adult monocytes, newborn monocytes demonstrated markedly impaired BCG-induced production of lactate, a metabolite implicated in immune training in adults.

Conclusions

BCG-induced human monocyte primary- and memory-innate cytokine responses were age-dependent and accompanied by distinct immunometabolic shifts that impact both glycolysis and training. Our results suggest that immune ontogeny may shape innate responses to live attenuated vaccines, suggesting age-specific approaches to leverage innate training for broad protection against infection.

[Efficacy of probiotics in preventing late-onset sepsis in very low birth weight infants: a Meta analysis]

OBJECTIVE

To study the efficacy of probiotics in preventing late-onset sepsis (LOS) in very low birth weight (VLBW) infants.

METHODS

Databases including PubMed, Web of Science, Cochrane Library, Wanfang Data, China National Knowledge Infrastructure, and Chinese Biomedical Literature Database were searched for randomized controlled trials (RCTs) of probiotics in preventing LOS in VLBW infants. LOS was classified as clinical LOS and confirmed LOS. RevMan 5.4 was used to perform the Meta analysis.

RESULTS

A total of 31 RCTs were included, with 3 490 VLBW infants in the probiotics group and 3 376 VLBW infants in the control group. The Meta analysis showed that compared with the control group, the probiotics group had significantly lower risks of clinical LOS (RR=0.79, 95%CI:0.66-0.94, P=0.009) and clinical/confirmed LOS (RR=0.79, 95% CI:0.67-0.94, P=0.007). In the probiotics group, the infants receiving exclusive breastfeeding had a significantly lower risk of confirmed LOS (RR=0.77, 95%CI:0.62-0.96, P=0.02).

CONCLUSIONS

Current evidence indicates that probiotics may reduce the risk of clinical LOS and clinical/confirmed LOS in VLBW infants, and the risk of confirmed LOS in VLBW infants who are exclusively breastfed.

Impaired Cytokine Responses to Live Staphylococcus epidermidis in Preterm Infants Precede Gram-positive, Late-onset Sepsis

BACKGROUND

Late-onset sepsis (LOS) with Staphylococcus epidermidis is common in preterm infants, but the immunological mechanisms underlying heightened susceptibility are poorly understood. Our aim is to characterize the ontogeny of cytokine responses to live S. epidermidis in preterm infants with and without subsequent Gram-positive LOS.

METHODS

We conducted a prospective, observational cohort study of preterm infants (<30 weeks gestational age [GA]) with blood sampling on Days 1, 7, 14, 21, and 28 of life. Cytokine responses in peripheral whole blood stimulated with live S. epidermidis were analyzed by 11-plex immunoassay.

RESULTS

Of 129 infants (mean GA, 26.2 weeks; mean birth weight, 887g), 23 (17.8%) had confirmed LOS with Gram-positive organisms and 15 (11.6%) had clinical sepsis, with median onsets at 13 and 15 days, respectively. Blood cytokine responses to an in vitro S. epidermidis challenge were similar between infected and uninfected infants on Day 1, but diverged thereafter. Infants with subsequent LOS displayed broadly reduced S. epidermidis-induced responses from Day 7 onwards, compared to those who did not develop LOS. This pattern was observed with chemokines (interleukin [IL]-8, monocyte chemotactic protein-1, and macrophage inflammatory protein-1α), pro-inflammatory cytokines (IL-1, IL-6, and tumor necrosis factor-α) and the regulatory cytokine IL-10.

CONCLUSIONS

Cytokine responses to a live S. epidermidis challenge are impaired in infants with LOS and precede the onset of clinical illness. Quantifying pathogen-specific cytokine responses at Day 7 may identify those high-risk preterm infants at the greatest risk of LOS, and prospective replication is warranted.

Cause of preterm birth and late-onset sepsis in very preterm infants: the EPIPAGE-2 cohort study

BACKGROUND

The pathogenesis of late-onset sepsis (LOS) in preterm infants is poorly understood and knowledge about risk factors, especially prenatal risk factors, is limited. This study aimed to assess the association between the cause of preterm birth and LOS in very preterm infants.

METHODS

2052 very preterm singletons from a national population-based cohort study alive at 72 h of life were included. Survival without LOS was compared by cause of preterm birth using survival analysis and Cox regression models.

RESULTS

437 (20.1%) had at least one episode of LOS. The frequency of LOS varied by cause of preterm birth: 17.1% for infants born after preterm labor, 17.9% after preterm premature rupture of membranes, 20.3% after a placental abruption, 20.3% after isolated hypertensive disorders, 27.5% after hypertensive disorders with fetal growth restriction (FGR), and 29.4% after isolated FGR. In multivariate analysis, when compared to infants born after preterm labor, the risk remained higher for infants born after hypertensive disorders (hazard ratio HR = 1.7, 95% CI = 1.2-2.5), hypertensive disorders with FGR (HR = 2.6, 95% CI = 1.9-3.6) and isolated FGR (HR = 2.9, 95% CI = 1.9-4.4).

CONCLUSION

Very preterm infants born after hypertensive disorders or born after FGR had an increased risk of LOS compared to those born after preterm labor.

IMPACT

Late-onset sepsis risk differs according to the cause of preterm birth. Compared with those born after preterm labor, infants born very preterm because of hypertensive disorders of pregnancy and/or fetal growth restriction display an increased risk for late-onset sepsis. Antenatal factors, in particular the full spectrum of causes leading to preterm birth, should be taken into consideration to better prevent and manage neonatal infectious morbidity and inform the parents.

Cyclic AMP in human preterm infant blood is associated with increased TLR-mediated production of acute-phase and anti-inflammatory cytokines in vitro

BACKGROUND

Preterm infants are at high risk of infection and have distinct pathogen recognition responses. Suggested mechanisms include soluble mediators that enhance cellular levels of cAMP. The aim of this study was to assess the relationship between blood cAMP concentrations and TLR-mediated cytokine production in infants during the first month of life.

METHODS

Cord and serial peripheral blood samples (days of life 1-28) were obtained from a cohort of very preterm (<30 weeks' gestational age) and term human infants. Whole-blood concentrations of cAMP and FSL-1 and LPS in vitro stimulated cytokine concentrations were measured by ELISA and multiplex bead assay.

RESULTS

cAMP concentrations were higher in cord than in peripheral blood, higher in cord blood of female preterm infants, and lower at Days 1 and 7 in infants exposed to chorioamnionitis, even after adjusting for leukocyte counts. TLR2 and TLR4-mediated TNF-α, IL-1β, IL-6, IL-12p70, and IL-10 production in vitro increased over the first month of life in preterm infants and were positively correlated with leukocyte-adjusted cAMP levels and reduced by exposure to chorioamnionitis.

CONCLUSIONS

The ontogeny of blood cAMP concentrations and associations with chorioamnionitis and TLR-mediated production of cytokines suggest that this secondary messenger helps shape distinct neonatal pathogen responses in early life.

Exploring the Role of Gut Bacteria in Health and Disease in Preterm Neonates

The mortality rate of very preterm infants with birth weight <1500 g is as high as 15%. The survivors till discharge have a high incidence of significant morbidity, which includes necrotising enterocolitis (NEC), early-onset neonatal sepsis (EONS) and late-onset neonatal sepsis (LONS). More than 25% of preterm births are associated with microbial invasion of amniotic cavity. The preterm gut microbiome subsequently undergoes an early disruption before achieving bacterial maturation. It is postulated that bacterial gut colonisation at birth and postnatal intestinal dysbacteriosis precede the development of NEC and LONS in very preterm infants. In fact, bacterial colonization patterns in preterm infants greatly differ from term infants due to maternal chorioamnionitis, gestational age, delivery method, feeding type, antibiotic exposure and the environment factor in neonatal intensive care unit (NICU). In this regard, this review provides an overview on the gut bacteria in preterm neonates' meconium and stool. More than 50% of preterm meconium contains bacteria and the proportion increases with lower gestational age. Researchers revealed that the gut bacterial diversity is reduced in preterm infants at risk for LONS and NEC. Nevertheless, the association between gut dysbacteriosis and NEC is inconclusive with regards to relative bacteria abundance and between-sample beta diversity indices. With most studies show a disruption of the Proteobacteria and Firmicutes preceding the NEC. Hence, this review sheds light on whether gut bacteria at birth either alone or in combination with postnatal gut dysbacteriosis are associated with mortality and the morbidity of LONS and NEC in very preterm infants.

Pathological staging of chorioamnionitis contributes to complications in preterm infants

Objective

To investigate the effect of pathological staging of chorioamnionitis (CA) on complications in preterm infants;

Methods

A single-center, retrospective study was conducted to choose singleton preterm infants (gestational age < 37 weeks) from the Department of Obstetrics and Gynecology in our hospital from December 2016 to December 2017. The basic data and placental pathological results were retrospectively collected. According to the placental pathological results of whether inflammation infiltrating amnion, CA 0/I phase was classified into non-amnionitis group, CA II/III phase was classified into amnionitis group, the incidence of common complications in preterm infants was compared. Further, logistic regression was used to analyze the effects of amnionitis on complications after being adjusted to gestational age, birth weight and thrombocytopenia.

Results

A total of 221 preterm infants were enrolled, including 186 cases in non-amnionitis group and 35 cases in amnionitis group. The gestational age of amnionitis group (32.00 ± 2.71 weeks) was significantly lower than non-amnionitis group (34.14 ± 2.06 weeks), birth weight (1.93 ± 0.64 kg) was significantly lower than that of non-amnionitis group (2.26 ± 0.58 kg), and the hospital stay in amnionitis group was significantly longer (25.71 ± 19.23 days), all of the difference above was statistically significant(P < 0.05). The incidence of intraventricular hemorrhage (IVH) in amnionitis group (37.14%) was significantly higher than that in non-amnionitis group (13.98%) (P = 0.002), and the risk of IVH was significantly increased by amnionitis (OR = 3.636, 95%CI: 1.632–8.102); after correction of gestational age, birth weight and thrombocytopenia, the risk of IVH was still significantly increased (OR = 2.471, P = 0.046, 95% CI: 1.015–6.015). And the late-onset IVH was more common (P = 0.009).

Conclusion

Amnionitis leads to a significant reduction in gestational age and birth weight in preterm infants, and it is an independent risk factor for IVH.

Expression of S100A Alarmins in Cord Blood Monocytes Is Highly Associated With Chorioamnionitis and Fetal Inflammation in Preterm Infants

Background: Preterm infants exposed to chorioamnionitis and with a fetal inflammatory response are at risk for neonatal morbidity and adverse outcome. Alarmins S100A8, S100A9, and S100A12 are expressed by myeloid cells and have been associated with inflammatory activation and monocyte modulation.

Aim: To study S100A alarmin expression in cord blood monocytes from term healthy and preterm infants and relate results to clinical findings, inflammatory biomarkers and alarmin protein levels, as well as pathways identified by differentially regulated monocyte genes.

Methods: Cord blood CD14+ monocytes were isolated from healthy term (n = 10) and preterm infants (<30 weeks gestational age, n = 33) by MACS technology. Monocyte RNA was sequenced and gene expression was analyzed by Principal Component Analysis and hierarchical clustering. Pathways were identified by Ingenuity Pathway Analysis. Inflammatory proteins were measured by Multiplex ELISA, and plasma S100A proteins by mass spectrometry. Histological chorioamnionitis (HCA) and fetal inflammatory response syndrome (FIRS) were diagnosed by placenta histological examination.

Results: S100A8, S100A9, and S100A12 gene expression was significantly increased and with a wider range in preterm vs. term infants. High S100A8 and S100A9 gene expression (n = 17) within the preterm group was strongly associated with spontaneous onset of delivery, HCA, FIRS and elevated inflammatory proteins in cord blood, while low expression (n = 16) was associated with impaired fetal growth and physician-initiated delivery. S100A8 and S100A9 protein levels were significantly lower in preterm vs. term infants, but within the preterm group high S100A gene expression, spontaneous onset of labor, HCA and FIRS were associated with elevated protein levels. One thousand nine hundred genes were differentially expressed in preterm infants with high vs. low S100A alarmin expression. Analysis of 124 genes differentially expressed in S100A high as well as FIRS and HCA groups identified 18 common pathways and S100A alarmins represented major hubs in network analyses.

Conclusion: High expression of S100A alarmins in cord blood monocytes identifies a distinct clinical risk group of preterm infants exposed to chorioamnionitis and with a fetal inflammatory response. Gene and pathway analyses suggest that high S100A alarmin expression also affects monocyte function. The connection with monocyte phenotype and inflammation-stimulated S100A expression in other cell types (e.g., neutrophils) warrants further investigation.

Association of Histological and Clinical Chorioamnionitis With Neonatal Sepsis Among Preterm Infants: A Systematic Review, Meta-Analysis, and Meta-Regression

Chorioamnionitis (CA) is considered a key risk factor for very preterm birth and for developing early onset sepsis (EOS) in preterm infants, but recent data suggest that CA might be protective against late onset sepsis (LOS). We performed a systematic review and meta-analysis of studies exploring the association between CA and sepsis. A comprehensive literature search was performed in PubMed/MEDLINE and EMBASE, from their inception to December 1, 2018. A random-effects model was used to calculate odds ratios (OR) and 95% confidence intervals (CI). Sources of heterogeneity were analyzed by subgroup and meta-regression analyses. The following categories of sepsis were analyzed: EOS, LOS, unspecified onset sepsis (UOS), culture-proven, and clinical sepsis. CA was subdivided into clinical and histological chorioamnionitis. Funisitis was also analyzed. We found 3,768 potentially relevant studies, of which 107 met the inclusion criteria (387,321 infants; 44,414 cases of CA). Meta-analysis showed an association between any CA and any EOS (OR 4.29, CI 3.63-5.06), any LOS (OR 1.29, CI 1.11-1.54), and any UOS (OR 1.59, CI 1.11-1.54). Subgroup analysis showed that CA was associated with culture-proven EOS (OR 4.69, CI 3.91-5.56), clinical EOS (OR 3.58, CI 1.90-6.76), and culture-proven LOS (OR 1.31, CI 1.12-1.53), but not with clinical LOS (OR 1.52, CI 0.78-2.96). The presence of funisitis did not increase the risk of either EOS or LOS when compared with CA without funisitis. CA-exposed infants had lower gestational age (-1.11 weeks, CI -1.37 to -0.84) than the infants not exposed to CA. Meta-regression analysis showed that the lower gestational age of the CA group correlated with the association between CA and LOS but not with the association between CA and EOS. In conclusion, our data suggest that the positive association between chorioamnionitis and LOS may be modulated by the effect of chorioamnionitis on gestational age.

Histological chorioamnionitis is predicted by early infant C-reactive protein in preterm infants and correlates with neonatal outcomes

AIM

Histological chorioamnionitis (HCA) is associated with preterm birth and adverse neonatal outcomes. We evaluated the rise in C-reactive protein (CRP) in preterm infants as a predictor of HCA severity and outcomes.

METHODS

Consecutive preterm infants, born January 2009 to January 2014 in the National Maternity Hospital, Dublin, under 32 weeks' gestation or <1.5 kg birthweight, were included. Histological chorioamnionitis was staged as maternal inflammatory response, foetal inflammatory response and non-HCA.

RESULTS

Preterm infants (n = 518) were included with a mean gestational age 28.5 ± 2.8 weeks, birthweight 1.1 ± 0.3 kg, and 53.5% were male. Histological chorioamnionitis was found in 25.4%. Histological chorioamnionitis was present in 93.7% when CRP > 5 mg/L, 65.2% when CRP 1-5 mg/L and in 19.4% when CRP < 1 mg/L. When both the immature to total neutrophil (IT) ratio was >0.2 and the CRP > 1 mg/L the positive predictive value and negative predictive value for HCA were 92.5% and 84.9%, respectively. Histological chorioamnionitis was associated with more resuscitation and respiratory distress syndrome (both P < .001). A CRP > 10 mg/L was associated with a foetal inflammatory response and increased early-onset sepsis.

CONCLUSION

Higher early CRP was a surrogate predictor of HCA and correlated with the severity of HCA. Higher CRP and HCA were associated with adverse early outcomes.

BCG as a Case Study for Precision Vaccine Development: Lessons From Vaccine Heterogeneity, Trained Immunity, and Immune Ontogeny

Vaccines have been traditionally developed with the presumption that they exert identical immunogenicity regardless of target population and that they provide protection solely against their target pathogen. However, it is increasingly appreciated that vaccines can have off-target effects and that vaccine immunogenicity can vary substantially with demographic factors such as age and sex. Bacille Calmette-Guérin (BCG), the live attenuated Mycobacterium bovis vaccine against tuberculosis (TB), represents a key example of these concepts. BCG vaccines are manufactured under different conditions across the globe generating divergent formulations. Epidemiologic studies have linked early life immunization with certain BCG formulations to an unanticipated reduction (∼50%) in all-cause mortality, especially in low birthweight males, greatly exceeding that attributable to TB prevention. This mortality benefit has been related to prevention of sepsis and respiratory infections suggesting that BCG induces "heterologous" protection against unrelated pathogens. Proposed mechanisms for heterologous protection include vaccine-induced immunometabolic shifts, epigenetic reprogramming of innate cell populations, and modulation of hematopoietic stem cell progenitors resulting in altered responses to subsequent stimuli, a phenomenon termed "trained immunity." In addition to genetic differences, licensed BCG formulations differ markedly in content of viable mycobacteria key for innate immune activation, potentially contributing to differences in the ability of these diverse formulations to induce TB-specific and heterologous protection. BCG immunomodulatory properties have also sparked interest in its potential use to prevent or alleviate autoimmune and inflammatory diseases, including type 1 diabetes mellitus and multiple sclerosis. BCG can also serve as a model: nanoparticle vaccine formulations incorporating Toll-like receptor 8 agonists can mimic some of BCG's innate immune activation, suggesting that aspects of BCG's effects can be induced with non-replicating stimuli. Overall, BCG represents a paradigm for precision vaccinology, lessons from which will help inform next generation vaccines.

Urinary I-FABP, L-FABP, TFF-3, and SAA Can Diagnose and Predict the Disease Course in Necrotizing Enterocolitis at the Early Stage of Disease

Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease affecting mainly preterm newborns. It is characterized by unexpected onset and rapid progression with specific diagnostic signs as pneumatosis intestinalis or gas in the portal vein appearing later in the course of the disease. Therefore, we analyzed diagnostic and prognostic potential of the markers of early NEC pathogenesis, such as excessive inflammatory response (serum amyloid A (SAA)) and gut epithelium damage (intestinal and liver fatty acid-binding protein (I-FABP and L-FABP, respectively) and trefoil factor-3 (TFF-3)). We used ELISA to analyze these biomarkers in the urine of patients with suspected NEC, either spontaneous or surgery-related, or in infants without gut surgery (controls). Next, we compared their levels with the type of the disease (NEC or sepsis) and its severity. Already at the time of NEC suspicion, infants who developed NEC had significantly higher levels of all tested biomarkers than controls and higher levels of I-FABP and L-FABP than those who will later develop sepsis. Infants who will develop surgery-related NEC had higher levels of I-FABP and L-FABP than those who will develop sepsis already during the first 6 hours after the abdominal surgery. I-FABP was able to discriminate between infants who will develop NEC or sepsis and the SAA was able to discriminate between medical and surgical NEC. Moreover, the combination of TFF-3 with I-FABP and SAA could predict pneumatosis intestinalis, and the combination of I-FABP, L-FABP, and SAA could predict gas in the portal vein or long-term hospitalization and low SAA predicts early full enteral feeding. Thus, these biomarkers may be useful not only in the early, noninvasive diagnostics but also in the subsequent NEC management.

Differences in clinical characteristics of early- and late-onset neonatal sepsis caused by Klebsiella pneumoniae

To identify differences in the clinical characteristics of early- and late-onset sepsis (EOS and LOS) caused by Klebsiella pneumoniae (K. pneumoniae) and to describe the risk factors for multidrug-resistant K. pneumoniae (MDR-KP) infection. Infants with K. pneumoniae-induced sepsis who were admitted to a children's Hospital between Jan 2000 and Dec 2019 were included. All infants were divided into EOS and LOS groups, as well as MDR-KP and non-MDR-KP groups. Demographics, clinical characteristics, and risk factors were compared between the two groups. One hundred eighty infants (66 with EOS and 114 with LOS) were further analyzed, accounting for 36.8% of sepsis cases caused by MDR-KP. The frequency of respiratory failure, bronchopulmonary dysplasia, and intraventricular hemorrhage were more common in the LOS group and a higher rate of acute respiratory distress syndrome was more common in infants in the EOS group (P < 0.05). K. pneumoniae showed a low sensitivity to penicillin, beta-lactams and cephalosporins, and it showed a high sensitivity to levofloxacin, ciprofloxacin, and amikacin. Prematurity, low birth weight, longer antibiotic exposure time, long duration of peripheral catheter insertion, long mechanical ventilation time, and long parenteral nutrition time were associated with an increased rate of MDR-KP infection by univariate analysis (P < 0.05). The regression analysis identified a long antibiotic exposure time (OR = 1.37, 95% CI: 1.01-1.89) and long parenteral nutrition time (OR = 1.39, 95% CI: 1.01-1.89) as independent risk factors for a MDR-KP infection, and a greater gestational age and birth weight were associated with a lower risk of MDR-KP infection (OR = 0.57, 95% CI: 0.40-0.79). LOS caused by K. pneumoniae may lead to a higher frequency of complications. The risk factors for MDR-KP infection were longer duration of antibiotic exposure and parenteral nutrition. A greater gestational age and larger birth weight may decrease the risk of MDR-KP infection.

A perfect storm: fetal inflammation and the developing immune system

Histologic chorioamnionitis is an inflammatory disorder of the placenta that commonly precedes preterm delivery. Preterm birth related to chorioamnionitis and fetal inflammation has been associated with a risk for serious inflammatory complications in infancy. In addition, preterm infants exposed to chorioamnionitis may be more susceptible to infection in the neonatal intensive care unit and possibly later in life. A significant body of work has established an association between chorioamnionitis and inflammatory processes. However, the potential consequences of this inflammation on postnatal immunity are less understood. In this review, we will discuss current knowledge regarding the effects of fetal exposure to inflammation on postnatal immune responses.

TREC and KREC in very preterm infants: reference values and effects of maternal and neonatal factors

Objective: T-cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) assays have been used for severe combined immunodeficiencies newborn screening (NBS). We assessed TREC and KREC NBS values in preterm infants and investigated if perinatal characteristics affect their values.Methods: We performed a retrospective study collecting data from TREC and KREC NBS database and from mothers' and infants' medical charts.Results: TREC and KREC values were lower in preterm infants born at 23-31 or 32-36 weeks of gestation than in term infants. Gestational age <28 weeks of gestation, leukopenia, and hypertensive disorders of pregnancy lowered TREC. Hypertensive disorders of pregnancy lowered KREC and intrapartum fever >38 °C increased it. Low TREC and KREC values were not associated to the risk of developing early-onset sepsis and late-onset sepsis.Conclusion: TREC and KREC levels are lower in preterm than term infants, but this did not increase the risk of neonatal sepsis.

Prenatal inflammation suppresses blood Th1 polarization and gene clusters related to cellular energy metabolism in preterm newborns

Chorioamnionitis (CA, fetal membrane inflammation) predisposes to preterm birth and is associated with increased neonatal infection risk, but the separate effects of prematurity, CA, and postnatal adaptations on this risk are unclear. Using pigs as models for infants, we examined the systemic immune-metabolic status in cesarean-delivered preterm pigs, with and without CA induced by intra-amniotic (IA) LPS exposure. At birth, cord blood of preterm pigs showed neutropenia and low expressions of innate and adaptive immune genes, relative to term pigs. IA LPS induced CA and fetal systemic innate immune activation via complement and neutrophil-related pathways. These were mainly modulated via cellular regulations rather than granulopoiesis, as validated by the in vitro LPS stimulation of cord blood. After birth, IA LPS-exposed preterm pigs did not follow normal immune-metabolic ontogenies found in fetuses or newborns without prenatal insults, but showed consistently high levels of Treg, impaired Th1 polarization, and reduced expressions of multiple genes related to cellular oxidative phosphorylation and ribosomal activities. In conclusion, our results provide cellular and molecular evidence for CA-induced distinct neonatal immune-metabolic status with increased disease tolerance strategy, suggesting mechanisms for the clinical observation of elevated sepsis risks in immune-compromised preterm infants born with CA.

Evidence that intra-amniotic infections are often the result of an ascending invasion - a molecular microbiological study

Background Microbial invasion of the amniotic cavity resulting in intra-amniotic infection is associated with obstetrical complications such as preterm labor with intact or ruptured membranes, cervical insufficiency, as well as clinical and histological chorioamnionitis. The most widely accepted pathway for intra-amniotic infection is the ascension of microorganisms from the lower genital tract. However, hematogenous dissemination of microorganisms from the oral cavity or intestine, retrograde seeding from the peritoneal cavity through the fallopian tubes, and introduction through invasive medical procedures have also been suggested as potential pathways for intra-amniotic infection. The primary reason that an ascending pathway is viewed as most common is that the microorganisms most often detected in the amniotic fluid are those that are typical inhabitants of the vagina. However, thus far, no studies have shown that microorganisms in the amniotic cavity are simultaneously present in the vagina of the woman from which they were isolated. The objective of the study was to determine the frequency with which microorganisms isolated from women with intra-amniotic infection are also present in the lower genital tract. Methods This was a cross-sectional study of women with intra-amniotic infection with intact membranes. Intra-amniotic infection was defined as a positive culture and elevated concentrations of interleukin-6 (IL-6) (>2.6 ng/mL) in amniotic fluid and/or acute histologic chorioamnionitis and funisitis. Microorganisms isolated from bacterial cultures of amniotic fluid were taxonomically identified through matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) and 16S ribosomal RNA (rRNA) gene sequencing. Vaginal swabs were obtained at the time of amniocentesis for the identification of microorganisms in the lower genital tract. The overall bacterial profiles of amniotic fluids and vaginal swabs were characterized through 16S rRNA gene sequencing. The bacterial profiles of vaginal swabs were interrogated for the presence of bacteria cultured from amniotic fluid and for the presence of prominent (>1% average relative abundance) operational taxonomic units (OTUs) within the overall 16S rRNA gene bacterial profiles of amniotic fluid. Results (1) A total of 75% (6/8) of women had bacteria cultured from their amniotic fluid that are typical residents of the vaginal ecosystem. (2) A total of 62.5% (5/8) of women with bacteria cultured from their amniotic fluid also had these bacteria present in their vagina. (3) The microorganisms cultured from amniotic fluid and also detected in the vagina were Ureaplasma urealyticum, Escherichia coli, and Streptococcus agalactiae. (4) 16S rRNA gene sequencing revealed that the amniotic fluid of women with intra-amniotic infection had bacterial profiles dominated by Sneathia, Ureaplasma, Prevotella, Lactobacillus, Escherichia, Gardnerella, Peptostreptococcus, Peptoniphilus, and Streptococcus, many of which had not been cultured from the amniotic fluid samples. (5) Seventy percent (7/10) of the prominent (>1% average relative abundance) OTUs found in amniotic fluid were also prominent in the vagina. Conclusion The majority of women with intra-amniotic infection had bacteria cultured from their amniotic fluid that were typical vaginal commensals, and these bacteria were detected within the vagina at the time of amniocentesis. Molecular microbiological interrogation of amniotic fluid from women with intra-amniotic infection revealed that the bacterial profiles of amniotic fluid were largely consistent with those of the vagina. These findings indicate that ascension from the lower genital tract is the primary pathway for intra-amniotic infection.

Association of Chorioamnionitis With Bronchopulmonary Dysplasia Among Preterm Infants: A Systematic Review, Meta-analysis, and Metaregression

IMPORTANCE

Bronchopulmonary dysplasia (BPD), a chronic lung disease of prematurity, remains one of the major and most common complications of very preterm birth. Insight into factors associated with the pathogenesis of BPD is key to improving its prevention and treatment.

OBJECTIVE

To perform a systematic review, meta-analysis, and metaregression of clinical studies exploring the association between chorioamnionitis (CA) and BPD in preterm infants.

DATA SOURCES

PubMed and Embase were searched without language restriction (last search, October 1, 2018). Key search terms included bronchopulmonary dysplasia, chorioamnionitis, and risk factors.

STUDY SELECTION

Included studies were peer-reviewed studies examining preterm (<37 weeks' gestation) or very low-birth-weight (<1500 g) infants and reporting primary data that could be used to measure the association between exposure to CA and the development of BPD.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline was followed. Data were independently extracted by 2 researchers. A random-effects model was used to calculate odds ratios (ORs) and 95% CIs. Heterogeneity in effect size across studies was studied using multivariate, random-effects metaregression analysis.

MAIN OUTCOMES AND MEASURES

The primary outcome was BPD, defined as supplemental oxygen requirement on postnatal day 28 (BPD28) or at the postmenstrual age of 36 weeks (BPD36). Covariates considered as potential confounders included differences between CA-exposed and CA-unexposed infants in gestational age, rates of respiratory distress syndrome (RDS), exposure to antenatal corticosteroids, and rates of early- and late-onset sepsis.

RESULTS

A total of 3170 potentially relevant studies were found, of which 158 met the inclusion criteria (244 096 preterm infants, 20 971 CA cases, and 24 335 BPD cases). Meta-analysis showed that CA exposure was significantly associated with BPD28 (65 studies; OR, 2.32; 95% CI, 1.88-2.86; P < .001; heterogeneity: I2 = 84%; P < .001) and BPD36 (108 studies; OR, 1.29; 95% CI, 1.17-1.42; P < .001; heterogeneity: I2 = 63%; P < .001). The association between CA and BPD remained significant for both clinical and histologic CA. In addition, significant differences were found between CA-exposed and CA-unexposed infants in gestational age, birth weight, odds of being small for gestational age, exposure to antenatal corticosteroids, and early- and late-onset sepsis. Chorioamnionitis was not significantly associated with RDS (48 studies; OR, 1.10; 95% CI, 0.92-1.34; P = .24; heterogeneity: I2 = 90%; P < .001), but multivariate metaregression analysis with backward elimination revealed that a model combining the difference in gestational age and the odds of RDS was associated with 64% of the variance in the association between CA and BPD36 across studies.

CONCLUSIONS AND RELEVANCE

The results of this study confirm that among preterm infants, exposure to CA is associated with a higher risk of developing BPD, but this association may be modulated by gestational age and risk of RDS.

Histological chorioamnionitis, antenatal steroids, and neonatal outcomes in very low birth weight infants: A nationwide study

Background

The aim of this study was to investigate whether some associations between histological chorioamnionitis (HCA) and favorable neonatal outcomes might be linked to those of antenatal steroids (AS) by determining the separate as well as the combined associations of HCA and AS with neonatal outcomes in very low birth weight infants (VLBWIs).

Methods

This was a population-based study of VLBWIs born at 20–33 weeks’ gestation between January 2013 and December 2015 from the Korean Neonatal Network. A total of 4652 VLBWIs were enrolled for prevalence study. Of these, 2900 singleton VLBWIs were used for outcome analyses to evaluate individual associations of HCA and AS simultaneously with correction for potential perinatal factors and an interaction term of HCA and AS.

Results

The overall prevalence of HCA was 34.9% (1623 VLBWIs). Multivariable logistic regression demonstrated that HCA was associated with decreased mortality (adjusted odds ratio [aOR], 0.51; 95% confidence interval [CI], 0.29–0.91; P = 0.022), AS were associated with reduction in mortality (aOR, 0.59; 95% CI, 0.39–0.90; P = 0.014) and neonatal seizure (aOR, 0.57; 95% CI, 0.37–0.86; P = 0.008), and a combination of HCA and AS was associated with remarkably lowered severe intraventricular hemorrhage by interacting with each other (aOR, 0.47; 95% CI, 0.25–0.88; P = 0.019).

Conclusions

We suggest that in VLBWIs HCA and AS may be favorable independent factors for neonatal outcome and may also work in synergy for neuroprotection.

Bronchopulmonary dysplasia frequency and risk factors in very low birth weight infants: A 3-year retrospective study

OBJECTIVE:

In this study, the relationship between the frequency of bronchopulmonary dysplasia, perinatal risk factors and other prematurity comorbidities were evaluated in very low birth weight infants.

METHODS:

A total of 872 very low birth weight infants’ files were retrospectively reviewed. The effects of the clinical parameters, such as type of birth, small for gestational age, gender, antenatal steroids, early membrane rupture, chorioamnionitis, surfactant administration, respiratory distress syndrome, patent ductus arteriosus, apnea, early and late sepsis on the frequency of bronchopulmonary dysplasia, were evaluated by binary logistic regression analysis.

RESULTS:

The overall mortality rate was 20.9%. After the first 28-day mortality reduction, the total bronchopulmonary dysplasia frequency was found to be 20.1%. The odds ratio and 95% confidence intervals of the factors affecting the development of bronchopulmonary dysplasia were found to be as follows respectively: respiratory distress syndrome (OR 6.2, 95% CI 3.6–10.6, p<0.01), patent ductus arteriosus (OR 4.9, 95% Cl 2.4–9.9, p<0.01), apnea (OR 4.1, 95% CI 2.5–6.9, p<0.01), late sepsis (OR 2.7, 95% CI 1.6–4.5, p<0.01), early membrane rupture (OR 2.6, 95% Cl 1.2–5.5, p=0.01), and male gender (OR 1.6, 95% CI 1.0-2.7, p=0.04) was found. However, there was no effect of chorioamnionitis, antenatal steroids, small for gestational age, early sepsis and type of birth on bronchopulmonary dysplasia.

CONCLUSION:

Differently from the usual factors which are low birth weight and a gestational week, there was a significant but non-linear risk relationship between respiratory distress syndrome, patent ductus arteriosus, late sepsis, apnea, early membrane rupture, male gender and bronchopulmonary dysplasia.

The relationship between histologic chorioamnionitis and decidual macrophage polarization and their influence on outcomes of neonates born before the 32nd gestational week

PURPOSE

To explore the relationship between histologic chorioamnionitis (HCA) and decidual macrophage (DM) polarization and their influence on outcomes of neonates born before the 32nd gestational week.

MATERIALS AND METHODS

Eighty-four neonates and their placentas were included in this retrospective case-control study and divided into two groups: with and without HCA present (HCA + and HCA-). Neonatal, maternal, and placental risk factors were explored and their influence on neonatal outcomes was examined. We used CD68 and iNOS as markers for polarized DMs type 1 (M1) and CD163, CD206 and arginase (Arg-1) for polarized DMs type 2 (M2).

RESULTS

HCA was present in 47 (56%) cases, and 37 (44%) cases were without the present HCA. There was no statistically significant difference in neonatal risk factors between the two groups (HCA + and HCA-). Higher rates of HCA (p = .042) were observed in mothers who received antepartum corticosteroid therapy. The frequency of vaginal deliveries in HCA + pregnancies was significantly higher than in HCA- pregnancies where deliveries by cesarean section were more frequently observed (p < .001). M2 DM were more abundant in the HCA + group (p = .035). Multiple regression model assessed the association between the presence of HCA, M1, and M2 DM with ROP stages. It has been observed that HCA is a risk factor for ROP stages (β coefficient = 0.34, r_partial = 0.246, p = .024). With the logistic regression model, the association between the presence of HCA, M1, and M2 DM with neonatal nCPAP respiratory support and necrotizing enterocolitis (NEC) was assessed. The presence of M2 macrophages in decidua is an independent risk factor for neonatal nCPAP respiratory support (coefficient -0.07, OR = 0.928, 95% CI 0.87-0.99, p = .024) and the presence of M1 macrophages in decidua increases the risk for NEC (coefficient 0.010, OR = 1.0108, 95% CI 1.00-1.02, p = .032).

CONCLUSIONS

The significantly more abundant presence of M2 DM was detected in HCA + placentas and their association with the increased risk for neonatal nCPAP respiratory support was observed. On the contrary, the presence of M1 DM increases the risk for NEC. The presence of HCA is a risk factor for ROP stages.

Postnatal inflammation following intrauterine inflammation exacerbates the development of atherosclerosis in ApoE−/− mice

Atherosclerosis is a chronic inflammatory disease that has its origins in early life. Postnatal inflammation exacerbates atherosclerosis, but the possible effect of intrauterine inflammation is largely unexplored. Exposure to inflammation in utero is common, especially in infants born preterm, who have increased cardiovascular risk in adulthood. We hypothesised that exposure to inflammation before birth would accelerate the development of atherosclerosis, with the most severe atherosclerosis following exposure to both pre- and postnatal inflammation. Here we studied the effect of prenatal and postnatal inflammation on the development of atherosclerosis by combining established techniques for modelling histological chorioamnionitis and atherosclerosis using apolipoprotein E (ApoE) knockout mice. A single intra-amniotic (IA) injection of lipopolysaccharide (LPS) caused intrauterine inflammation, and increased atherosclerosis at 13 weeks of postnatal age. In mice exposed to postnatal LPS, chorioamnionitis modulated subsequent responses; atherosclerotic lesion size, number and severity were greatest for mice exposed to both intrauterine and postnatal inflammation, with a concomitant decrease in collagen content and increased inflammation of the atherosclerotic plaque. In conclusion, pre- and postnatal inflammation have additive and deleterious effects on the development of atherosclerosis in ApoE knockout mice. The findings are particularly relevant to preterm human infants, whose gestations are frequently complicated by chorioamnionitis and who are particularly susceptible to repeated postnatal infections. Human and mechanistic studies are warranted to guide preventative strategies.

Impact of different stages of intrauterine inflammation on outcome of preterm neonates: Gestational age-dependent and -independent effect

Objective

To investigate the impact of different stages of intrauterine inflammation (IUI) on neonatal outcomes, before and after adjusting for gestational age (GA) and other perinatal confounders.

Methods

This was an observational, prospective, single-center cohort study including all eligible neonates with GA < 35 weeks and/or birth weight ≤ 1500 g born at a 3^rd level Neonatal Intensive Care Unit between 2011 and 2014. Pathological patterns of placenta, membranes and cord were classified according to Redline’s criteria. Multivariable linear and logistic regression models were applied, either including or not GA among the covariates.

Results

Of the 807 enrolled neonates, 134 (16.6%) had signs of IUI: among these, 54.5% showed just histological chorioamnionitis (HCA), 25.4% had HCA + funisitis (FUN) stage 1, and 20.1% had HCA + FUN stage 2–3. At univariate analysis, HCA increased the risk for retinopathy of prematurity (ROP) and bronchopulmonary dysplasia, while FUN (any stage) had a deleterious impact on all outcomes investigated. After adjustment for covariates not including GA, HCA was a risk factor only for ROP (OR = 2.8, CI: 1–7.8), while FUN (any stage) was still associated with increased ORs for all outcomes (p <0.01). Upon inclusion of GA in the regression model, the results differed remarkably. HCA was associated with lower risk for mechanical ventilation (OR = 0.3, CI: 0.1–0.7) and need for surfactant (OR = 0.5, CI: 0.2–0.9), while FUN (any stage) worsened clinical conditions at birth (p <0.05), increased the risk for early-onset sepsis (p <0.01), and increased the length of mechanical ventilation (FUN stage 2–3 only, RC = 6.5 days, CI: 2–11). No other outcome was affected.

Conclusions

IUI, especially FUN, negatively impact most neonatal morbidities, but its effect is partially reverted adjusting for GA. Considered that GA is an intermediate variable interposed between prenatal causes of prematurity and outcomes, the appropriateness of adjusting for GA may be questionable.

Histological chorioamnionitis and developmental outcomes in very preterm infants

OBJECTIVE

To characterize the association of histological chorioamnionitis (HCA) with neurodevelopmental outcomes in children born at <30 weeks gestation.

STUDY DESIGN

This retrospective cohort study included infants born 2006-2012 in whom placental histopathology, neonatal outcomes, and Bayley-III assessment at age 2 years were available. We assessed the association of HCA exposure with cognitive, language, and motor delay with logistic regression models adjusted for gestational age, sex, small for gestational age and brain injury.

RESULTS

Of 1353 infants, 985 had histological and neonatal data available, and 708 infants had Bayley-III assessments. HCA-exposed infants were at higher risk of some neonatal adverse outcomes, and stage of HCA correlated with low Apgar score and early-onset sepsis. Exposure to HCA was not associated with neurodevelopmental outcomes in adjusted models including stage of HCA.

CONCLUSIONS

Exposure to HCA, especially higher stage, was associated with neonatal morbidity but not with adverse neurodevelopmental outcomes at 2 years of age.

Chorioamnionitis exposure remodels the unique histone modification landscape of neonatal monocytes and alters the expression of immune pathway genes

Chorioamnionitis is an intrauterine infection involving inflammation of the chorion, amnion, and placenta. It leads to a fetal systemic inflammatory response that can alter the transcription of neonatal immune genes. We have previously shown that neonatal monocytes gain the activating histone tail modification H3K4me3 at promoter sites of immunologically important genes as development progresses from preterm neonate to adult. In this study, we applied ChIP-seq and RNA-seq to evaluate the impact of chorioamnionitis on the neonatal monocyte H3K4me3 histone modification landscape over the course of fetal and neonatal immune system development. Chorioamnionitis exposure in neonatal monocytes resulted in a net increase in total monocyte H3K4me3, primarily in introns and intergenic regions. Immune gene expression was decreased in chorioamnionitis-exposed monocytes, with the majority of enriched transcripts falling into pathways that are not linked to the immune system. Over half of all neonatal monocyte H3K4me3 peaks, independent of their location, were associated with active gene transcription. Overall, chorioamnionitis exposure resulted in the global remodeling of the neonatal monocyte H3K4me3 landscape and changes in the expression of known immune genes. These changes resulted in a less robust inflammatory response upon exposure to a secondary challenge, which may explain why chorioamnionitis-exposed neonates have an increased risk of sepsis. DATABASE: ChIP-seq data for U30/O30/Term: GEO GSE81957 ChIP-seq data for U30C/O30C/TermC: GEO GSE111873 RNA-seq data for U/L/CU/CL: GEO GSE111927.

[Epidemiology, risk factors and child prognosis: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVES

To synthetize the available evidence regarding the incidence and risk factors of preterm premature rupture of membranes (PPROM). To describe the evolution of pregnancy, neonatal outcomes and the prognosis of infants born in a context of PPROM, according to the existence of an associated intrauterine infection and to the latency duration.

METHOD

Consultation of the Medline database, from 1980 to February 2018.

RESULTS

PPROM before 37 and before 34 weeks' gestation occur in 2-3% and <1% of pregnancies, respectively (LE2). Although many risk factors are identified, few are modifiable, and the vast majority of patients have no risk factors (LE2). Consequently, individual prediction of the risk of PPROM and primary prevention measures have not been shown to be effective and are not recommended in clinical practice (Grade B). Most women give birth within the week following PPROM (LE2). The main complications of PPROM are prematurity, intrauterine infection and obstetric and maternal complications (LE2). Latency duration and the frequency of complications decrease with increasing gestational age at PPROM (LE2). Neonatal prognosis is largely conditioned by gestational age at birth, with no apparent over-risk of poor outcomes linked to PPROM compared to other causes of preterm birth (LE2). In contrast, intrauterine infection is associated with an increased risk of in utero fetal death (LE3), necrotizing enterocolitis (LE1) and early-onset sepsis (LE2). The association of intrauterine infection with neurological morbidity remains controversial. Prolongation of latency, from gestational age at PPROM, is beneficial for the child (LE2).

CONCLUSION

PPROM is a major cause of prematurity and short- and long-term mortality and morbidity. Antenatal care is an important issue for obstetric and pediatric teams, aiming to reduce complications and adverse consequences for both mother and child.

Immunomodulation to Prevent or Treat Neonatal Sepsis: Past, Present, and Future

Despite continued advances in neonatal medicine, sepsis remains a leading cause of death worldwide in neonatal intensive care units. The clinical presentation of sepsis in neonates varies markedly from that in older children and adults, and distinct acute inflammatory responses results in age-specific inflammatory and protective immune response to infection. This review first provides an overview of the neonatal immune system, then covers current mainstream, and experimental preventive and adjuvant therapies in neonatal sepsis. We also discuss how the distinct physiology of the perinatal period shapes early life immune responses and review strategies to reduce neonatal sepsis-related morbidity and mortality. A summary of studies that characterize immune ontogeny and neonatal sepsis is presented, followed by discussion of clinical trials assessing interventions such as breast milk, lactoferrin, probiotics, and pentoxifylline. Finally, we critically appraise future treatment options such as stem cell therapy, other antimicrobial protein and peptides, and targeting of pattern recognition receptors in an effort to prevent and/or treat sepsis in this highly vulnerable neonatal population.

Exposure to chorioamnionitis alters the monocyte transcriptional response to the neonatal pathogen Staphylococcus epidermidis

Preterm infants are uniquely susceptible to late-onset sepsis that is frequently caused by the skin commensal Staphylococcus epidermidis. Innate immune responses, particularly from monocytes, are a key protective mechanism. Impaired cytokine production by preterm infant monocytes is well described, but few studies have comprehensively assessed the corresponding monocyte transcriptional response. Innate immune responses in preterm infants may be modulated by inflammation such as prenatal exposure to histologic chorioamnionitis which complicates 40-70% of preterm pregnancies. Chorioamnionitis alters the risk of late-onset sepsis, but its effect on monocyte function is largely unknown. Here, we aimed to determine the impact of exposure to chorioamnionitis on the proportions and phenotype of cord blood monocytes using flow cytometry, as well as their transcriptional response to live S. epidermidis. RNA-seq was performed on purified cord blood monocytes from very preterm infants (<32 weeks gestation, with and without chorioamnionitis-exposure) and term infants (37-40 weeks), pre- and postchallenge with live S. epidermidis. Preterm monocytes from infants without chorioamnionitis-exposure did not exhibit an intrinsically deficient transcriptional response to S. epidermidis compared to term infants. In contrast, chorioamnionitis-exposure was associated with hypo-responsive transcriptional phenotype regarding a subset of genes involved in antigen presentation and adaptive immunity. Overall, our findings suggest that prenatal exposure to inflammation may alter the risk of sepsis in preterm infants partly by modulation of monocyte responses to pathogens.

Bacteriological profile and antibiotic susceptibility pattern of common isolates of neonatal sepsis, Ho Municipality, Ghana-2016

Background

Globally, 4 million neonates die annually, with one-third of such deaths occurring as a result of infections. In 2011, there were 7.2million deaths in children below 5 years globally, and a proportion of 40% of these deaths occurred in neonates. Sepsis was reported to account for one-third of these deaths. Presently, multidrug antibiotic resistance is rapidly increasing in Neonatal Intensive Care Units (NICUs), particularly in developing countries and poses a threat to public health. The change in these organisms has been reported to vary across regions, between health facilities and even within the same facility. Continuous surveillance is required to inform antibiotic choice for neonatal sepsis management. We identified the common causative organisms of neonatal sepsis and their antibiotic susceptibility pattern in the Ho municipality.

Method

A cross sectional study was conducted in the Ho municipality from January to May, 2016. A semi-structured questionnaire was used to collect socio-demographic data from mothers of neonates with clinically suspected of sepsis. Clinical data of both mothers and neonates were extracted from case notes. A 2 ml volume of blood was also taken from neonates and dispensed into a 20 ml mixture of thioglycollate fluid broth and tryptone soy broth for culture and antibiotic susceptibility pattern determined.

Results

Out of the 150 clinically suspected neonatal sepsis cases, 91 (60.7%) were males. The Median gestational week was 38 (IQR: 36-39) and Median birthweight was 3.0 kg (IQR 2.5-3.4). The prevalence of culture positive sepsis was 17.3% of the 150 suspected cases. A total of 26 different pathogens were isolated, of which gram positive organisms had a preponderance of 18 (69%) over gram negative organisms 8 (31%). Staphylococcus epidermidis was the most common 14 (53.8%) isolate identified. There was a single isolate (4%) each of Proteus mirabilis and Escherichia coli identified. All the isolates identified showed 100% resistance to ampicillin.

Conclusion

The prevalence of culture proven sepsis was 17.3% and Staphylococcus epidermidis was the most common isolate identified. Pathogens isolated were resistant to the first line drugs for management of neonatal sepsis. Hence, the need for a review of first line drug for empirical treatment in neonatal sepsis.

Identification of generic and pathogen-specific cord blood monocyte transcriptomes reveals a largely conserved response in preterm and term newborn infants

Escherichia coli and Staphylococcus epidermidis are predominant causes of neonatal sepsis, particularly affecting preterm infants. Susceptibility to infection has been attributed to "immature" innate monocyte defences, but no studies have assessed global transcriptional responses of neonatal monocytes to these pathogens. Here, we aimed to identify and characterise the neonatal monocyte transcriptional responses to E. coli and S. epidermidis and the role of common modifiers such as gestational age (GA) and exposure to chorioamnionitis (a common complication of preterm birth) to better understand early life innate immune responses. RNA-sequencing was performed on purified cord blood monocytes from very preterm (< 32 weeks GA) and term infants (37-40 weeks GA) following standardised challenge with live S. epidermidis or E. coli. The major transcriptional changes induced by either pathogen were highly conserved between infant groups and stimuli, highlighting a common extant neonatal monocyte response to infection, largely mediated by TLR/NF-κB/TREM-1 signalling. In addition, we observed an activated interferon-centred immune response specific to stimulation with E. coli in both preterm and term infants. These data provide novel insights into the functionality of neonatal monocytes at birth and highlight potential pathways that could be targeted to reduce the harmful effects of bacterial-induced inflammation in sepsis. E. coli and S. epidermidis elicit common transcriptional changes in cord monocytes. The common transcriptional response is mediated by TLR/NF-κB/TREM-1 signalling. IFN genes are differentially regulated by E. coli and S. epidermidis in monocytes. These responses are largely unaffected by GA or exposure to chorioamnionitis.

KEY MESSAGES

E. coli and S. epidermidis elicit common transcriptional changes in cord monocytes. The common transcriptional response is mediated by TLR/NF-κB/TREM-1 signalling. IFN-genes are differentially regulated by E. coli and S. epidermidis in monocytes. These responses are largely unaffected by GA or exposure to chorioamnionitis.

Probiotics and antimicrobial protein and peptide levels in preterm infants

AIM

To characterise the secreted and inducible antimicrobial protein and peptide (APP) levels in a prospective cohort of preterm infants (<30 weeks gestational age) with or without Bifidobacterium breve M16V supplementation during the first month of life.

METHODS

We analysed serial biosamples of infants who did (n = 13) or did not receive (n = 62) B. breve (3 × 10⁹ cfu/day). Peripheral blood was obtained on days 1, 14 and 28, and infant stool prior to commencement of probiotic supplementation and on day 21. Levels of APP (bactericidal/permeability inducing protein (BPI), beta defensins 1 and 2, lactoferrin, human cathelicidin, secretory phospholipase A2) in plasma and stool were determined. Further, we characterised induced APP levels in whole blood cultured with live S. epidermidis or with agonists of Toll-like receptors 2/6 and 4.

RESULTS

Stool, plasma and stimulated blood APP levels changed significantly during the first month of life. Supplementation with B. breve did not affect basal or stimulated APP levels except for a transient increase in inducible BPI.

CONCLUSION

Supplementation with B. breve does not appear to act via modulation of systemic or enteric APP expression in preterm infants although small effects cannot be excluded. Further work with other probiotic preparations is warranted.

Impact of Early-Life Exposures to Infections, Antibiotics, and Vaccines on Perinatal and Long-term Health and Disease

Essentially, all neonates are exposed to infections, antibiotics, or vaccines early in their lives. This is especially true for those neonates born underweight or premature. In contrast to septic adults and children who are at an increased risk for subsequent infections, exposure to infection during the neonatal period is not associated with an increased risk of subsequent infection and may be paradoxically associated with reductions in late-onset sepsis (LOS) in the most premature infants. Perinatal inflammation is also associated with a decreased incidence of asthma and atopy later in life. Conversely, septic neonates are at increased risk of impaired long-term neurodevelopment. While the positive effects of antibiotics in the setting of infection are irrefutable, prolonged administration of broad-spectrum, empiric antibiotics in neonates without documented infection is associated with increased risk of LOS, necrotizing enterocolitis, or death. Vaccines provide a unique opportunity to prevent infection-associated disease; unfortunately, vaccinations have been largely unsuccessful when administered in the first month of life with the exception of vaccines against hepatitis B and tuberculosis. Future vaccines will require the use of novel adjuvants to overcome this challenge. This review describes the influence of infections, antibiotics, and vaccines during the first days of life, as well as the influence on future health and disease. We will also discuss potential immunomodulating therapies, which may serve to train the preterm immune system and reduce subsequent infectious burden without subjecting neonates to the risks accompanied by virulent pathogens.

Whole Blood Profiling of Bacillus Calmette-Guérin-Induced Trained Innate Immunity in Infants Identifies Epidermal Growth Factor, IL-6, Platelet-Derived Growth Factor-AB/BB, and Natural Killer Cell Activation

Vaccination of infants with bacillus Calmette-Guérin (BCG) activates both the innate and adaptive arms of the immune response. The antimycobacterial effects of these responses most likely account for the ability of BCG to protect against childhood forms of tuberculosis (TB). There is also evidence for a heterologous protective effect of BCG vaccination against TB-unrelated mortality in low birth weight infants. A possible mechanism of action of this effect, the induction of trained innate immunity, has been demonstrated when cells from BCG-vaccinated adults are restimulated in vitro with non-related microbial stimuli. Our aim was to examine an extensive panel of secreted immune biomarkers to characterize the profile of trained innate immunity in infants. Stimulation of whole blood for 48 h was performed 4 months after BCG vaccination, or in control unvaccinated infants. Stimulants were lipopolysaccharide; Pam3Cys (P3C); heat-killed Candida albicans, Staphylococcus aureus, Escherichia coli, and a lysate of Mycobacterium tuberculosis. Culture supernatants were tested for secreted cytokines and chemokines by 42-plex bead array and monocytes and natural killer (NK) cells assessed for expression of activation markers by flow cytometry. BCG-vaccinated infants displayed increases in 11 cytokines and chemokines in response to different non-specific innate immunity stimuli: epidermal growth factor (EGF); eotaxin; IL-6; IL-7; IL-8; IL-10; IL-12p40; monocyte chemotactic protein-3; macrophage inflammatory protein-1α; soluble CD40 ligand and platelet-derived growth factor (PDGF)-AB/BB. Although each stimulant induced a distinct response profile, three analytes, EGF, IL-6, and PDGF-AB/BB, were commonly higher after stimulation with Pam3Cys, C. albicans, and S. aureus. Conversely, certain cytokines such as interferon gamma-inducible protein-10, IL-2, IL-13, IL-17, GM-CSF, and GRO were suppressed in BCG-vaccinated infants, while no increases in TNFα or IL-1β production were detected. We did not observe a concomitant, BCG-associated change in monocyte surface activation markers in response to non-specific stimuli, but we detected a significant increase in CD69 expression on NK cells in response to Pam3Cys. Pam3Cys-induced NK cell activation correlated with the magnitude of IL-12p40 and IL-10 responses to the same stimulant. This study reveals a novel cytokine/chemokine biomarker signature of BCG-induced trained innate immunity in infants and the involvement of NK cells in these responses.

Maternal Chorioamnionitis and Postneonatal Respiratory Tract Infection in Ex-Preterm Infants

OBJECTIVE

To assess whether exposure to histologically confirmed chorioamnionitis (ie, histologic chorioamnionitis [HCA]) is associated with altered risk of infection-related hospitalization (IRH) during the first 24 months of life in very preterm infants.

STUDY DESIGN

This single-center retrospective cohort study analyzed data on 1218 infants born at <30 weeks gestational age (GA). Semiquantitative placental histology, obstetric, and neonatal data were extracted from hospital databases and linked with discharge diagnoses on rehospitalization until age 24 months from statewide statutory data. The associations between HCA and overall and clinical categories of IRH were analyzed by Cox proportional hazards regression with left-truncated failure times.

RESULTS

Mean GA was 27 weeks, and HCA was present in 577 placentas (47.4%). Among the 1088 infants surviving until the birth-related discharge, 684 (62.9%) of had at least 1 IRH by age 24 months, of whom 287 included a diagnosis of acute lower respiratory tract infection (ALRTI). Following adjustment for sex, birth weight z-score, GA, early-onset sepsis, late-onset sepsis, previous antibiotic use, age at birth-related discharge, and chronic lung disease, HCA was associated with a 32% increased risk of hospitalization with ALRTI (HR, 1.32; 95% CI, 1.02-1.70; P = .033). There was no association with infection overall or with other infection categories.

CONCLUSIONS

HCA is associated with a significantly increased risk of hospitalization with ALRTI that is independent of known risk factors, including chronic lung disease.

Human alkaline phosphatase dephosphorylates microbial products and is elevated in preterm neonates with a history of late-onset sepsis

BACKGROUND

A host defense function for Alkaline phosphatases (ALPs) is suggested by the contribution of intestinal ALP to detoxifying bacterial lipopolysaccharide (endotoxin) in animal models in vivo and the elevation of ALP activity following treatment of human cells with inflammatory stimuli in vitro. However the activity of ALP in human plasma (primarily tissue-nonspecific ALP; TNAP) on lipopolysaccharide and other microbial products has not been assessed, nor has its expression been studied in preterm newborns, a vulnerable population at high risk of sepsis. In this context, the aim of our study was to characterize the activity of TNAP on Toll-like receptor (TLR) agonists and assess the concentrations of plasma ALP during late-onset sepsis in preterm newborns.

METHODS

Recombinant human TNAP was incubated with microbial products and phosphate release was measured by malachite green assay. Plasma ALP activity was measured serially in a cohort of preterm (N = 129) infants at high risk of late-onset sepsis (LOS).

RESULTS

TNAP dephosphorylates poly-inosine:cytosine (Toll-like receptor (TLR) 3 agonist) and LPS from Klebsiella pneumoniae and Salmonella minnesota (TLR4 agonists). Plasma ALP significantly increased postnatally over the first 4 weeks of life in preterm and term newborns. Bacteremic LOS in preterm infants (gestational age ≤ 30 weeks) was associated with significantly elevated plasma ALP at 4 weeks postnatal age.

CONCLUSIONS

TNAP, the main circulating isozyme of ALP, de-phosphorylates TLR agonists, demonstrates a post-natal age dependent increase in preterm and term plasma across the first 4 weeks of life, and is elevated in association with preterm LOS.

Associations of Maternal Testosterone and Cortisol Levels With Health Outcomes of Mothers and Their Very-Low-Birthweight Infants

OBJECTIVE

Although the roles of testosterone and cortisol in various health problems have been extensively investigated, little is known about their associations with health outcomes in mothers and their very-low-birthweight (VLBW) infants when maternal testosterone and cortisol are examined together during the postpartum period.

METHOD

The 101 mother-VLBW infant pairs were recruited from the neonatal intensive care unit of a tertiary medical center in the southeastern United States. Demographic information, pregnancy and labor complications of mothers, and health and growth outcomes of infants were obtained from medical records and interviews with mothers. Maternal salivary testosterone and cortisol levels were determined using enzyme immunoassay.

RESULTS

Linear regression showed that mothers who were older and had a larger body mass index experienced more pregnancy complications, whereas mothers who were single and had a cesarean section experienced more labor complications. Generalized linear models showed that mothers with high cortisol levels had more antepartum hemorrhage, whereas infants of mothers with high cortisol levels had fewer neurological insults and shorter hospitalizations than other infants. More mothers experienced premature prolonged rupture of membranes (PPROM) than chorioamnionitis, and maternal medical complications were negatively associated with infant health outcomes except PPROM, which was positively associated with infant outcomes.

CONCLUSIONS

High maternal cortisol levels were associated with maternal health problems during pregnancy. Beneficial effects of PPROM and high maternal cortisol levels on infant health outcomes were important findings, and understanding the mechanisms of these relationships may be of practical value for clinicians and researchers.