Histologic chorioamnionitis and umbilical serum levels of pro-inflammatory cytokines and cytokine inhibitors

Plasma proteomic signature of neonates in the context of placental histological chorioamnionitis

BACKGROUND

Placental histological chorioamnionitis (HCA) is recognised as a significant risk factor for various adverse neonatal outcomes. This study aims to explore if the inflammatory protein levels in neonates were associated with HCA.

METHODS

All women with singleton births from February 2020 to November 2022 were selected and divided into three groups based on maternal placental pathology results: the HCA-stage 1 group (n=24), the HCA-stage 2 group (n=16) and the control group (n=17). Olink Target 96 Inflammation Panel was used to detect the levels of 92 inflammation-related proteins in the plasma of newborns from all three groups within 24 hours after birth. We compared the protein profiles through differential protein expression analysis.

RESULTS

A total of six inflammation-related proteins exhibited significant differences between the HCA-stage 1 and the control group. Specifically, TRANCE and CST5 were significantly upregulated (p=0.006, p=0.025, respectively), whereas the expression of IFN-gamma, CXCL9, CXCL10 and CCL19 was significantly downregulated (p=0.040, p=0.046, p=0.007, p=0.006, respectively). HCA-stage 2 newborns had significantly elevated levels of CD5 and CD6 and decreased IFN-gamma, CXCL10 and CCL19 in comparison to controls. These differential proteins were significantly enriched in positive regulation of cytokine activity, leucocyte chemotaxis and positive regulation of T-cell activation pathway-related Gene Ontology terms. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that viral protein interaction with cytokine and cytokine receptor, interleukin-17/NF-kappa B/toll-like receptor/chemokine signalling pathway, and cytokine-cytokine receptor interaction exhibited significant differences. Spearman analysis demonstrated a significant positive connection between the levels of CD6 and CD5 proteins, not only in neonatal leucocytes but also in maternal leucocytes. Additionally, CD6 was found to be associated with neonatal birth weight.

CONCLUSIONS

In conclusion, placental histological changes associated with chorioamnionitis appear to influence the expression of inflammatory proteins in offspring. Notably, CD6 and CD5 proteins may potentially contribute to the pathogenesis of HCA-related neonatal diseases.

Placental clearance not synthesis tempers exaggerated pro-inflammatory cytokine response in neonates exposed to chorioamnionitis

BACKGROUND

The source and clearance of cytokines in the fetal circulation in term pregnancies complicated by chorioamnionitis remains unclear as are the contributions of placental transport, synthesis, and clearance. The objectives of the study were to determine (1) fetal and/or placental contributions to synthesis and/or clearance of inflammatory and anti-inflammatory cytokines in term pregnancies complicated by chorioamnionitis and (2) whether this differs in pregnancies further complicated by fetal hypoxia.

METHODS

Prospective cohort study of pregnancies >37 weeks gestational age that included: Group 1, uncomplicated cesarean delivery without labor (n = 20); Group 2, uncomplicated vaginal delivery (n = 30); Group 3, pregnancies complicated by chorioamnionitis (n = 10); Group 4, complicated by chorioamnionitis + fetal hypoxia (n = 10). Umbilical arterial (UmA) and venous (UmV) blood were assayed for IL-1β, IL-2, IL-6, IL-8, TNFα, and IL-10.

RESULTS

IL-6 and IL-8 were below assay detection in UmA and UmV blood in Group 1 and increased in Group 2 (P < 0.01), UmA»UmV (P < 0.01). Their concentrations increased further in Groups 3 and 4 (P = 0.003), UmA»UmV. Placental clearance was concentration dependent that approaches saturation in the presence of chorioamnionitis.

CONCLUSIONS

Marked increases in fetal synthesis of IL-6 and IL-8 occur in chorioamnionitis. Synthesis increase further when complicated by fetal hypoxia. Cytokine removal occurs via placental concentration-dependent mechanisms, potentially contributing to adverse fetal effects.

IMPACT

The source and role of the placenta in synthesis and/or clearance of inflammatory mediators in term pregnancies complicated by clinical chorioamnionitis are unclear; however, conventional wisdom suggests the placenta is their source. This is the first study demonstrating that circulating concentrations of fetal IL-6 and IL-8 in clinical chorioamnionitis ± birth asphyxia in term pregnancies are of fetal origin. Circulating fetal inflammatory cytokines are cleared by concentration-dependent placental mechanisms that are nearly saturated in chorioamnionitis ± fetal hypoxia. These observations provide additional insight into understanding the fetal immune response in term pregnancies complicated by clinical chorioamnionitis.

The role of interleukin-1 in perinatal inflammation and its impact on transitional circulation

Preterm birth is defined as delivery at <37 weeks of gestational age (GA) and exposes 15 million infants worldwide to serious early life diseases. Lowering the age of viability to 22 weeks GA entailed provision of intensive care to a greater number of extremely premature infants. Moreover, improved survival, especially at extremes of prematurity, comes with a rising incidence of early life diseases with short- and long-term sequelae. The transition from fetal to neonatal circulation is a substantial and complex physiologic adaptation, which normally happens rapidly and in an orderly sequence. Maternal chorioamnionitis or fetal growth restriction (FGR) are two common causes of preterm birth that are associated with impaired circulatory transition. Among many cytokines contributing to the pathogenesis of chorioamnionitis-related perinatal inflammatory diseases, the potent pro-inflammatory interleukin (IL)-1 has been shown to play a central role. The effects of utero-placental insufficiency-related FGR and in-utero hypoxia may also be mediated, in part, via the inflammatory cascade. In preclinical studies, blocking such inflammation, early and effectively, holds great promise for improving the transition of circulation. In this mini-review, we outline the mechanistic pathways leading to abnormalities in transitional circulation in chorioamnionitis and FGR. In addition, we explore the therapeutic potential of targeting IL-1 and its influence on perinatal transition in the context of chorioamnionitis and FGR.

Placental pathology as a marker of brain injury in infants with hypoxic ischemic encephalopathy

BACKGROUND

Hypoxic Ischemic Encephalopathy (HIE) can lead to devastating consequences for the affected infant. Although therapeutic cooling benefits infants with moderate and severe HIE, differentiating mild from moderate-severe HIE may be challenging. The placenta reflects the fetal intrauterine environment and may reveal underlying processes that affect brain injury.

AIM

To describe placental histopathology using the Amsterdam Placental Workshop Group Criteria in different grades of HIE.

STUDY DESIGN

Retrospective cohort.

SUBJECTS

Infants admitted to a tertiary care neonatal intensive care unit with a diagnosis of HIE between 2011 and 2016.

OUTCOME MEASURE

Maternal and neonatal clinical variables and placental histopathology using the Amsterdam Placental Workshop Group Criteria were compared between mild and moderate-severe HIE. Mann-Whitney or t-test or ꭓ² were performed for bivariate associations as appropriate. To explain the relationship between placental pathology and severity of HIE odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using logistic regression models.

RESULTS

Of the 73 infants in the study, 23 had mild and 50 moderate-sever HIE. There was no difference in maternal and neonatal characteristics except for sentinel events which were higher in the moderate- severe group. On placental histopathology, acute inflammation, including fetal inflammatory reaction (FIR) were significantly higher in the moderate-severe group. After adjusting for confounders, FIR remained significantly associated with moderate-severe HIE, ORs 6.29, 95 % CI 1.5-25.

CONCLUSION

Our study demonstrates FIR in the placenta is associated with severity of HIE.

Gestational Age Dependency of Umbilical Cord Serum IL-6 Levels for Detecting Fetal Inflammation

OBJECTIVE

The fetal inflammatory response syndrome (FIRS) is characterized by elevated concentrations of inflammatory cytokines in fetal blood, with preterm delivery and morbidity. Umbilical cord serum interleukin-6 (UC-s-IL-6) is an ideal marker for detecting FIRS. However, the effect of gestational age (GA) on UC-s-IL-6 levels has not been reported. This study aimed to determine the relationship between GA and UC-s-IL-6 levels, and GA-dependent cutoff values of UC-s-IL-6 levels for detecting fetal inflammation.

STUDY DESIGN

UC-s-IL-6 concentrations were measured in 194 newborns (44 extremely preterm newborns (EPNs) at 22-27 weeks' GA, 68 very preterm newborns (VPNs) at 28-31 weeks' GA, and 82 preterm newborns (PNs) at 32-34 weeks' GA). Linear regression analyses were used to correlate GA and UC-s-IL-6 levels. Receiver operating characteristic (ROC) curves analyses were performed for detecting the presence of funisitis, as the histopathological counterpart of FIRS.

RESULTS

A significant negative correlation between GA and UC-s-IL-6 levels was found in newborns with severe funisitis (r _s =  - 0.427, p = 0.004) and those with mild funisitis (r _s =  - 0.396, p = 0.025). ROC curve analyses revealed the area under the curve for detecting funisitis were 0.856, 0.837, and 0.622 in EPNs, VPNs, and PNs, respectively. The UC-s-IL-6 cutoff value in EPNs (28.1 pg/mL) exceeded those in VPNs and PNs (3.7 and 3.0 pg/mL, respectively).

CONCLUSION

UC-s-IL-6 levels were inversely correlated with GA especially in newborns with funisitis. Such GA dependency of UC-s-IL-6 should be considered for detecting fetal inflammation.

KEY POINTS

· IL-6 levels inversely correlate with GA.. · Higher IL-6 levels strongly indicate funisitis.. · Detecting cutoff values differ depending on GA..

Oxidative and Inflammatory Markers Are Higher in Full-Term Newborns Suffering Funisitis, and Higher Oxidative Markers Are Associated with Admission

The aim of this study was to assess whether oxidative and inflammatory mediators in the cord blood of newborns with funisitis and chorioamnionitis can serve as indicators of their inflammatory status, and whether there is a positive association between higher mediator levels and an increased risk of admission to the neonatal intensive care unit (NICU). This study was conducted prospectively in a neonatology department of a university hospital. In total, 52 full-term newborns were evaluated, including 17 funisitis cases, 13 chorioamnionitis cases, and 22 control newborns without funisitis or chorioamnionitis. Cord blood samples were measured for oxidative stress and inflammatory status markers. The oxidative stress markers included the total nitric oxide (NO), total hydroperoxide (TH), biological antioxidant potential (BAP), and TH/BAP ratio, comprising the oxidative stress index (OSI). Inflammatory markers included interleukin (IL)-1b, IL-6, IL-8, IL-10, tumor necrosis factor alpha (TNFα), interferon γ (IFNγ), and complement component C5a. TH, OSI, IL-1b, IL-6, and IL-8 concentrations were higher in the funisitis group than in the chorioamnionitis and control groups. C5a was higher in the funisitis and chorioamnionitis groups than in the control group. Among all enrolled newborns, 14 were admitted to the NICU. Multiple logistic regression analysis showed that elevated umbilical cord blood levels of OSI and TH were associated with a higher risk of admission to the NICU (OSI: R = 2.3, 95% CI 1.26–4.29, p = 0.007 and TH: R = 1.02, 95%CI = 1.004–1.040, p = 0.015). In conclusion, OSI and TH in cord blood from full-term newborns can provide an index of inflammatory status, and higher levels are associated with the risk of admission to the NICU and, therefore, could serve as an early indicator of inflammatory conditions in newborns.

Pregnancy tailors endotoxin-induced monocyte and neutrophil responses in the maternal circulation

Objective

To comprehensively characterize monocyte and neutrophil responses to E. coli and its product [lipopolysaccharide (LPS) or endotoxin] in vitro during pregnancy.

Material or subjects

Peripheral blood was collected from pregnant women during the third trimester (n = 20) and from non-pregnant women (n = 20).

Methods

The number, phagocytic activity, and reactive oxygen species (ROS) production of peripheral monocytes and neutrophils were investigated using flow cytometry. The phenotypes of peripheral monocytes and neutrophils after acute or chronic LPS stimulation were also determined using flow cytometry. Cytokine profiles were quantified for LPS-stimulated peripheral blood mononuclear cells (PBMCs) and a whole blood TruCulture^® system using a multiplex immunoassay.

Results

Increased number, phagocytic activity, and ROS production capacity of monocytes and neutrophils were found in pregnant compared to non-pregnant women. Additionally, specific subsets of pro-inflammatory monocytes (IL-6⁺CD14⁺ or MIP-1α⁺CD14⁺ cells) and neutrophils (IL-1β⁺CD15⁺ or MIP-1β⁺CD15⁺ cells) were increased in pregnant women in response to acute LPS stimulation. Moreover, distinct subsets of intermediate-activated monocytes expressing CD142, IL-6, and IL-1RA were increased in pregnant women upon chronic LPS stimulation. Last, pregnant women displayed a different cytokine profile than non-pregnant women in LPS-stimulated PBMCs and in whole blood.

Conclusions

Pregnancy tailors the immune responses of circulating monocytes and neutrophils to endotoxin, a Gram-negative bacterial product.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00011-022-01569-z.

A potent myeloid response is rapidly activated in the lungs of premature Rhesus macaques exposed to intra-uterine inflammation

Up to 40% of preterm births are associated with histological chorioamnionitis (HCA), which leads to elevated levels of pro-inflammatory mediators and microbial products in the amniotic fluid, which come in contact with fetal lungs. Yet, fetal pulmonary immune responses to such exposure remain poorly characterized. To address this gap, we used our established HCA model, in which pregnant Rhesus macaques receive intraamniotic (IA) saline or LPS. IA LPS induced a potent and rapid myeloid cell response in fetal lungs, dominated by neutrophils and monocytes/macrophages. Infiltrating and resident myeloid cells exhibited transcriptional profiles consistent with exposure to TLR ligands, as well as cytokines, notably IL-1 and TNFα. Although simultaneous, in vivo blockade of IL-1 and TNFα signaling did not prevent the inflammatory cell recruitment, it blunted the lung overall inflammatory state reducing communication between, and activation of, infiltrating immune cells. Our data indicate that the fetal innate immune system can mount a rapid multi-faceted pulmonary immune response to in utero exposure to inflammation. These data provide mechanistic insights into the association between HCA and the postnatal lung morbidities of the premature infant and highlight therapeutic potential of inflammatory blockade in the fetus.

Umbilical Cord Blood Leptin and IL-6 in the Presence of Maternal Diabetes or Chorioamnionitis

Diabetes during pregnancy is associated with elevated maternal insulin, leptin and IL-6. Within the placenta, IL-6 can further stimulate leptin production. Despite structural similarities and shared roles in inflammation, leptin and IL-6 have contrasting effects on neurodevelopment, and the relative importance of maternal diabetes or chorioamnionitis on fetal hormone exposure has not been defined. We hypothesized that there would be a positive correlation between IL-6 and leptin with progressively increased levels in pregnancies complicated by maternal diabetes and chorioamnionitis. To test this hypothesis, cord blood samples were obtained from 104 term infants, including 47 exposed to maternal diabetes. Leptin, insulin, and IL-6 were quantified by multiplex assay. Factors independently associated with hormone levels were identified by univariate and multivariate linear regression. Unlike IL-6, leptin and insulin were significantly increased by maternal diabetes. Maternal BMI and birth weight were independent predictors of leptin and insulin with birth weight the strongest predictor of leptin. Clinically diagnosed chorioamnionitis and neonatal sepsis were associated with increased IL-6 but not leptin. Among appropriate for gestational age infants without sepsis, IL-6 and leptin were strongly correlated (R=0.6, P<0.001). In summary, maternal diabetes and birth weight are associated with leptin while chorioamnionitis is associated with IL-6. The constraint of the positive association between leptin and IL-6 to infants without sepsis suggests that the term infant and placenta may have a limited capacity to increase cord blood levels of the neuroprotective hormone leptin in the presence of increased cord blood levels of the potential neurotoxin IL-6.

Preterm Birth Is Associated With Immune Dysregulation Which Persists in Infants Exposed to Histologic Chorioamnionitis

Introduction

Preterm infants are at increased risk of exposure to histologic chorioamnionitis (HCA) when compared to term-born controls, and this is associated with several neonatal morbidities involving brain, lungs and gut. Preterm infants could benefit from immunomodulatory therapies in the perinatal period, but development of rational treatment strategies requires improved characterization of the perinatal response to HCA. We had two objectives: The first, to characterize the umbilical cord blood immune profile in preterm infants compared to term-born controls; the second, to investigate the postnatal immune response in preterm infants exposed to HCA versus those who were not.

Population

For objective one 59 term infants [mean gestational age (GA) 39⁺⁴ (37⁺³ to 42⁺⁰)] and 55 preterm infants [mean GA29⁺⁰(23⁺³ to 32⁺⁰)] with umbilical cord samples available were included; for objective two we studied 96 preterm infants [mean GA29⁺¹(23⁺² to 32⁺⁰)] for whom placental histology and postnatal blood samples were available.

Methods

Placental histopathology was used to identify reaction patterns indicative of HCA, and a customized immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group.

Results

The umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242x10^-14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 8 immune proteins on postnatal day 5 (BDNF, C3, C5a, C9, IL-8, MCP-1, MIP-1β and MMP-9) when compared to preterm infants who were not exposed.

Conclusion

Preterm birth is associated with a distinct immune profile in umbilical cord blood and preterm infants exposed to HCA with evidence of a fetal inflammatory response have specific alterations in immune function that are apparent on day 5 of postnatal life.

Transabdominal amniocentesis in expectant management of preterm premature rupture of membranes: A single center prospective study

AIMS

The aim of this study was to evaluate the role of IL-6 point-of-care test in amniotic fluid obtained from serial amniocentesis in expectantly managed women with PPROM between 24 and 34 weeks of gestation.

METHODS

We conducted a prospective observational cohort study which included 62 pregnant women with PPROM in gestational weeks between 22+0 and 34+0. Women aged >18 years were eligible if they presented with PPROM and a singleton pregnancy. Only women who delivered at >24.0 weeks were included in the study. In all women, the maternal blood sampling and a transabdominal amniocentesis were performed at the time of admission prior to the administration of corticosteroids, antibiotics, or tocolytics, to rule out signs of chorioamnionitis. Maternal temperature, maternal serum C-reactive protein (CRP) and white blood cell (WBC) counts were assayed every subsequent day until delivery. Amniotic fluid was used for the clinical assessment (IL-6 point-of-care test, identification of microorganisms in the amniotic fluid. After one week of expectant management of PPROM, second amniocentesis with amniotic fluid sampling was performed in patients who did not deliver. For all newborns, medical records regarding neonatal morbidity and mortality were reviewed.

RESULTS

In total, 62 women aged 19 to 41 years were recruited in the study. The mean gestational age at the time of PPROM was 31+0, the mean gestational age at labor was 32+1, and the median time from PPROM to childbirth was 112 h. IL-6 point-of-care test values above 1,000 pg/mL (positive Il-6 AMC) were found in 12 women (19.4%) with median interval from PPROM to childbirth 56 h (min-max: 6.4-288). IL-6 point-of-care test values below 1,000 pg/mL (negative Il-6 AMC) were found in 51 women (81.0%). The neonatal mortality rate was 1.9% and was associated with prematurity.

CONCLUSION

The major clinical finding of our study is that serial transabdominal amniocentesis with Il-6 point-of-care test helps to identify a high inflammatory status in amniotic fluid in women with PPROM. Subsequent expectant management of women with PPROM does not lead to worsening of short-term neonatal outcomes.

In utero inflammatory challenge induces an early activation of the hepatic innate immune response in late gestation fetal sheep

Chorioamnionitis is associated with inflammatory end-organ damage in the fetus. Tissues in direct contact with amniotic fluid drive a pro-inflammatory response and contribute to this injury. However, due to a lack of direct contact with the amniotic fluid, the liver contribution to this response has not been fully characterized. Given its role as an immunologic organ, we hypothesized that the fetal liver would demonstrate an early innate immune response to an in utero inflammatory challenge. Fetal sheep (131 ± 1 d gestation) demonstrated metabolic acidosis and high cortisol and norepinephrine values within 5 h of exposure to intra-amniotic LPS. Likewise, expression of pro-inflammatory cytokines increased significantly at 1 and 5 h of exposure. This was associated with NF-κB activation, by inhibitory protein IκBα degradation, and nuclear translocation of NF-κB subunits (p65/p50). Corroborating these findings, LPS exposure significantly increased pro-inflammatory innate immune gene expression in fetal sheep hepatic macrophages in vitro. Thus, an in utero inflammatory challenge induces an early hepatic innate immune response with systemic metabolic and stress responses. Within the fetal liver, hepatic macrophages respond robustly to LPS exposure. Our results demonstrate that the fetal hepatic innate immune response must be considered when developing therapeutic approaches to attenuate end-organ injury associated with in utero inflammation.

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.

Pulmonary Consequences of Prenatal Inflammatory Exposures: Clinical Perspective and Review of Basic Immunological Mechanisms

Chorioamnionitis, a potentially serious inflammatory complication of pregnancy, is associated with the development of an inflammatory milieu within the amniotic fluid surrounding the developing fetus. When chorioamnionitis occurs, the fetal lung finds itself in the unique position of being constantly exposed to the consequent inflammatory meditators and/or microbial products found in the amniotic fluid. This exposure results in significant changes to the fetal lung, such as increased leukocyte infiltration, altered cytokine, and surfactant production, and diminished alveolarization. These alterations can have potentially lasting impacts on lung development and function. However, studies to date have only begun to elucidate the association between such inflammatory exposures and lifelong consequences such as lung dysfunction. In this review, we discuss the pathogenesis of and fetal immune response to chorioamnionitis, detail the consequences of chorioamnionitis exposure on the developing fetal lung, highlighting the various animal models that have contributed to our current understanding and discuss the importance of fetal exposures in regard to the development of chronic respiratory disease. Finally, we focus on the clinical, basic, and therapeutic challenges in fetal inflammatory injury to the lung, and propose next steps and future directions to improve our therapeutic understanding of this important perinatal stress.

Glutamate Transport and Preterm Brain Injury

Preterm birth complications are the leading cause of child death worldwide and a top global health priority. Among the survivors, the risk of life-long disabilities is high, including cerebral palsy and impairment of movement, cognition, and behavior. Understanding the molecular mechanisms of preterm brain injuries is at the core of future healthcare improvements. Glutamate excitotoxicity is a key mechanism in preterm brain injury, whereby the accumulation of extracellular glutamate damages the delicate immature oligodendrocytes and neurons, leading to the typical patterns of injury seen in the periventricular white matter. Glutamate excitotoxicity is thought to be induced by an interaction between environmental triggers of injury in the perinatal period, particularly cerebral hypoxia-ischemia and infection/inflammation, and developmental and genetic vulnerabilities. To avoid extracellular build-up of glutamate, the brain relies on rapid uptake by sodium-dependent glutamate transporters. Astrocytic excitatory amino acid transporter 2 (EAAT2) is responsible for up to 95% of glutamate clearance, and several lines of evidence suggest that it is essential for brain functioning. While in the adult EAAT2 is predominantly expressed by astrocytes, EAAT2 is transiently upregulated in the immature oligodendrocytes and selected neuronal populations during mid-late gestation, at the peak time for preterm brain injury. This developmental upregulation may interact with perinatal hypoxia-ischemia and infection/inflammation and contribute to the selective vulnerability of the immature oligodendrocytes and neurons in the preterm brain. Disruption of EAAT2 may involve not only altered expression but also impaired function with reversal of transport direction. Importantly, elevated EAAT2 levels have been found in the reactive astrocytes and macrophages of human infant post-mortem brains with severe white matter injury (cystic periventricular leukomalacia), potentially suggesting an adaptive mechanism against excitotoxicity. Interestingly, EAAT2 is suppressed in animal models of acute hypoxic-ischemic brain injury at term, pointing to an important and complex role in newborn brain injuries. Enhancement of EAAT2 expression and transport function is gathering attention as a potential therapeutic approach for a variety of adult disorders and awaits exploration in the context of the preterm brain injuries.

Placental Pathology in Neonatal Stroke: A Retrospective Case-Control Study

OBJECTIVE

To assess the association of placental abnormalities with neonatal stroke.

STUDY DESIGN

This retrospective case-control study at 3 academic medical centers examined placental specimens for 46 children with neonatal arterial or venous ischemic stroke and 99 control children without stroke, using a standard protocol. Between-group comparisons used χ² and Fisher exact t test. Correlations used Spearman correlation coefficient.

RESULTS

Case placentas were more likely than controls to meet criteria for ≥1 of 5 major categories of pathologic abnormality (89% vs 62%; OR, 5.1; 95% CI, 1.9-14.0; P = .0007) and for ≥2 categories (38% vs 8%; OR, 7.3; 95% CI, 2.9-19.0; P < .0001). Fetal vascular malperfusion occurred in 50% of cases and 17% of controls (OR, 4.8; 95% CI, 2.2-10.5; P = .0001). Amniotic fluid inflammation occurred in 46% of cases with arterial ischemic stroke vs 25% of controls (OR, 2.6; 95% CI, 1.1-6.1; P = .037). There was evidence of a "stress response" (meconium plus elevated nucleated red blood cells) in 24% of cases compared with 1% of controls (OR, 31; 95% CI, 3.8-247.0; P < .0001).

CONCLUSIONS

Placental abnormality was more common in children with neonatal stroke compared with controls. All placental findings represent subacute-to-chronic intrauterine stressors. Placental thrombotic processes were associated with both arterial and venous stroke. Our findings provide evidence for specific mechanisms that may predispose to acute perinatal stroke. Amniotic fluid inflammation associated with neonatal arterial ischemic stroke deserves further investigation.

A Role for the Inflammasome in Spontaneous Preterm Labor With Acute Histologic Chorioamnionitis

Inflammasomes are cytosolic multiprotein complexes that orchestrate inflammation in response to pathogens and endogenous danger signals. Herein, we determined whether the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis (1) express major inflammasome components; (2) express caspase (CASP)-1 and CASP-4 as well as their active forms; (3) exhibit apoptosis-associated speck-like protein containing a CARD (ASC)/CASP-1 complex formation; and (4) release the mature forms of interleukin (IL)-1β and IL-18. We utilized quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, immunoblotting, and immunohistochemistry to determine the messenger RNA (mRNA) and protein expression of major inflammasome components, nucleotide-binding oligomerization domain (NOD) proteins, and the pro- and mature/active forms of CASP-1, CASP-4, IL-1β, and IL-18. The ASC/CASP-1 complex formation was determined using an in situ proximity ligation assay. When comparing the chorioamniotic membranes from women in spontaneous preterm labor with acute histologic chorioamnionitis to those without this placental lesion, we found that (1) the mRNA of NLR family pyrin domain-containing protein ( NLRP) 1, NLRP3, NLR family CARD domain-containing protein 4 ( NLRC4), and NOD2 were higher; (2) the NLRP3 protein was increased; (3) the mRNA and active form (p10) of CASP-1 were greater; (4) the mRNA and active form of CASP-4 were increased; (5) the mRNA and mature form of IL-1β were higher; (6) the mature form of IL-18 was elevated; and (7) ASC/CASP-1 complex formation was increased. In conclusion, spontaneous preterm labor with acute histologic chorioamnionitis is characterized by an upregulation of NLRP3 and the active form of CASP-4, as well as increased ASC/CASP-1 complex formation, which may participate in the activation of CASP-1 and the maturation of IL-1β and IL-18 in the chorioamniotic membranes. These findings provide the first evidence that supports a role for the inflammasome in the pathological inflammation implicated in spontaneous preterm labor with acute histologic chorioamnionitis.

Neutrophil extracellular traps in acute chorioamnionitis: A mechanism of host defense

PROBLEM

Neutrophil extracellular traps (NETs) were recently described as a mechanism for microbial killing in the amniotic cavity of women with intra-amniotic infection. Such a clinical condition can result in acute chorioamnionitis, a placental lesion characterized by the infiltration of maternal neutrophils in the chorioamniotic membranes. Herein, we investigated whether these infiltrating neutrophils form NETs in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis.

METHOD OF STUDY

Chorioamniotic membrane samples were collected from women who underwent spontaneous term or preterm labor with acute chorioamnionitis (n=10 each). Controls included chorioamniotic membrane samples from women who delivered at term or preterm with or without labor in the absence of acute chorioamnionitis (n=10 each). NETs were visualized and semiquantified in the chorioamniotic membranes by using antibodies against neutrophil elastase and histone H3 in combination with DAPI staining.

RESULTS

Neutrophil extracellular traps were abundant in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis. NETs were rarely found, or not visualized at all, in the chorioamniotic membranes from women who delivered at term or preterm with or without labor in the absence of acute chorioamnionitis.

CONCLUSION

Neutrophil extracellular traps are abundant in the chorioamniotic membranes from women who underwent spontaneous term or preterm labor with acute chorioamnionitis. These findings suggest that chorioamniotic neutrophils can form NETs as a mechanism of host defense against infection or danger signals.

A Role for the Inflammasome in Spontaneous Labor at Term with Acute Histologic Chorioamnionitis

Inflammasomes are cytosolic signaling platforms that regulate the activation of caspase (CASP)-1, which induces the maturation of interleukin (IL)-1β and IL-18. Herein, we determined whether the chorioamniotic membranes from women in spontaneous labor at term with acute histologic chorioamnionitis express major inflammasome components and whether these changes are associated with the activation of CASP-1 and CASP-4 and the release of mature IL-1β and IL-18. When comparing the chorioamniotic membranes from women in spontaneous labor at term with acute histologic chorioamnionitis to those without this placental lesion, we found that (1) the messenger RNA (mRNA) abundance of NLR family pyrin domain containing 3 ( NLRP3), NLR family CARD domain containing 4 ( NLRC4), absent in melanoma 2 ( AIM2), and nucleotide binding oligomerization domain 2 ( NOD2) was higher; (2) the NLRP3 and NLRC4 protein quantities were increased; (3) the mRNA and protein expressions of CASP-1 and its active forms were greater; (4) CASP-4 was increased at the mRNA level only; (5) the mRNA and protein expressions of IL-1β and its mature form were higher; and (6) a modest increase in the total protein concentration and abundance of the mature form of IL-18 was observed. In vitro incubation of the chorioamniotic membranes with the CASP-1 inhibitor, VX765, decreased the release of endotoxin-induced IL-1β and IL-18 (2-fold) but not IL-6 or tumor necrosis factor α. In conclusion, spontaneous labor at term with acute histologic chorioamnionitis is characterized by an upregulation of inflammasome components which, in turn, may participate in the activation of CASP-1 and lead to the release of mature IL-1β by the chorioamniotic membranes. These results support a role for the inflammasome in the mechanisms responsible for spontaneous labor at term with acute histologic chorioamnionitis.

Fetal inflammation associated with minimal acute morbidity in moderate/late preterm infants

OBJECTIVE

To determine whether exposure to acute chorioamnionitis and fetal inflammation caused short-term adverse outcomes.

DESIGN

This is a prospective observational study: subjects were mothers delivering at 32-36 weeks gestation and their preterm infants at a large urban tertiary level III perinatal unit (N=477 infants). Placentae and fetal membranes were scored for acute histological chorioamnionitis based on the Redline criteria. Fetal inflammation was characterised by histological diagnosis of funisitis (umbilical cord inflammation), increased cord blood cytokines measured by ELISA, and activation of the inflammatory cells infiltrating the placenta and fetal membranes measured by immunohistology. Maternal and infant data were collected.

RESULTS

Twenty-four per cent of 32-36-week infants were exposed to histological chorioamnionitis and 6.9% had funisitis. Immunostaining for leucocyte subsets showed selective infiltration of the placenta and fetal membranes with activated neutrophils and macrophages with chorioamnionitis. Interleukin (IL) 6, IL-8 and granulocyte colony-stimulating factor were selectively increased in the cord blood of preterm infants with funisitis. Compared with infants without chorioamnionitis, funisitis was associated with increased ventilation support during resuscitation (43.8% vs 15.4%) and more respiratory distress syndrome postnatally (27.3% vs 10.2%) in univariate analysis. However, these associations disappeared after adjusting for prematurity.

CONCLUSIONS

Despite fetal exposure to funisitis, increased cord blood cytokines and activated placental inflammatory cells, we could not demonstrate neonatal morbidity specifically attributable to fetal inflammation after adjusting for gestational age in moderate and late preterm infants.

Zika Fetal Neuropathogenesis: Etiology of a Viral Syndrome

The ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain-Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of "TORCH" viral pathogenesis to provide context. By drawing parallels to other viral infections of the fetus, we identify common themes and mechanisms that may illuminate the observed pathology. The existing data on the susceptibility of various cells to both Zika and other flavivirus infections are summarized. Finally, we highlight relevant aspects of the known molecular mechanisms of flavivirus replication.

Optineurin suppression activates the mediators involved in the terminal effector pathways of human labour and delivery

Spontaneous preterm birth remains the major cause of neonatal death and morbidity. Studies in non-gestational tissues report that optineurin (OPTN) is critical in the termination of NFKB1 activity and control of inflammation, central features of spontaneous preterm birth. The aims of the present study were to determine: (1) OPTN expression in fetal membranes and the myometrium during labour; (2) the effects of IL1B on OPTN expression in primary myometrial cells; and (3) the effects of OPTN short interference (si) RNA on IL1B-stimulated proinflammatory and prolabour mediators. OPTN mRNA and protein expression was significantly decreased with spontaneous term labour in fetal membranes and the myometrium. Although there was no effect of spontaneous preterm labour on OPTN expression in fetal membranes, there was decreased OPTN expression in membranes with chorioamnionitis and myometrial cells treated with 1ng mL^-1 IL1B for 1 or 6h. In cells transfected with OPTN siRNA, significant increases were seen in IL1B-stimulated IL6, tumour necrosis factor, CXCL8 and monocyte chemoattractant protein-1 mRNA expression and release, cyclo-oxygenase-2 and prostanoid PTGFR receptor mRNA expression and the release of prostaglandin F_2α. There was no change in IL1B-stimulated NFKBIA expression; however, there was increased NFKB1 p65 DNA-binding activity. The results of the present study suggest that OPTN is a negative regulator of inflammation-induced prolabour mediators.

Prevalence of early-onset neonatal infection among newborns of mothers with bacterial infection or colonization: a systematic review and meta-analysis

BACKGROUND

Although neonatal infections cause a significant proportion of deaths in the first week of life, little is known about the burden of neonatal disease originating from maternal infection or colonization globally. This paper describes the prevalence of vertical transmission--the percentage of newborns with neonatal infection among newborns exposed to maternal infection.

METHODS

We searched Pubmed, Embase, Scopus, Web of Science, Cochrane Library, and WHO Regional Databases for studies of maternal infection, vertical transmission, and neonatal infection. Studies that measured prevalence of bacterial vertical transmission were included. Random effects meta-analyses were used to pool data to calculate prevalence estimates of vertical transmission.

RESULTS

122 studies met the inclusion criteria. Only seven studies (5.7%) were from very high neonatal mortality settings. Considerable heterogeneity existed between studies given the various definitions of infection (lab-confirmed, clinical signs), colonization, and risk factors of infection. The prevalence of early onset neonatal lab-confirmed infection among newborns of mothers with lab-confirmed infection was 17.2% (95%CI 6.5-27.9). The prevalence of neonatal lab-confirmed infection among newborns of colonized mothers was 0% (95% CI 0.0-0.0). The prevalence of neonatal surface colonization among newborns of colonized mothers ranged from 30.9-45.5% depending on the organism. The prevalence of neonatal lab-confirmed infection among newborns of mothers with risk factors (premature rupture of membranes, preterm premature rupture of membranes, prolonged rupture of membranes) ranged from 2.9-19.2% depending on the risk factor.

CONCLUSIONS

The prevalence of early-onset neonatal infection is high among newborns of mothers with infection or risk factors for infection. More high quality studies are needed particularly in high neonatal mortality settings to accurately estimate the prevalence of early-onset infection among newborns at risk.

Antioxidative status and oxidative stress in the fetal circulation at birth: the effects of time of delivery and presence of labor

BACKGROUND

There are important physiological changes in the maternal, placental, and fetal compartments during pregnancy and labor. Increased oxidative stress has been demonstrated during labor. Melatonin has been reported to serve as an indirect antioxidant via the stimulation and induction of antioxidant enzymes as superoxide dismutase (SOD) and glutathione peroxidase (Gpx) in several tissues.

AIM

: To assess whether the melatonin status, presence of labor at the time of birth and the time of delivery influence the extracellular antioxidative enzymes and DNA oxidative stress in newborns.

METHODS

The extracellular antioxidative status and oxidative stress were analyzed by measuring the concentrations of the SOD3, Gpx3 and 8-hydroxydeoxyguanosine (8-OHdG) in the cord blood of 135 newborns. Newborns delivered during the day and at night and newborns delivered by spontaneous vaginal delivery (labor group) or elective caesarean section delivery (no labor group) were studied.

OUTCOME MEASURES

The concentration of melatonin, SOD3, Gpx3 and 8-OHdG.

RESULTS

Independent of the time of delivery, we found significantly higher melatonin, SOD3 and Gpx3 but lower 8-OHdG concentrations in the labor group than in the no labor group. We did not observe a correlation between the concentration of melatonin and SOD3, Gpx3 or 8-OHdG, or a day-night difference in SOD3, Gpx3 or 8-OHdG.

CONCLUSION

Our findings suggest that oxidative stress during labor leads to an elevation of melatonin, SOD3 and Gpx3 in the fetal circulation, protecting the newborn from serious impairment, which is reflected by lower 8-OHdG levels. The melatonin status at the time of birth does not influence the extracellular SOD3 or Gpx3 concentrations.

Increased tissue levels of omega-3 polyunsaturated fatty acids prevents pathological preterm birth

Omega-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) have anti-inflammatory effects. Preterm birth is an important problem in modern obstetrics and one of the main causes is an inflammation. We here showed that abundance of omega-3 fatty acids reduced the incidence of preterm birth induced by LPS with fat-1 mice, capable of converting omega-6 to omega-3 fatty acids. We also indicated that the gene expression of IL-6 and IL-1β in uteruses and the number of cervical infiltrating macrophages were reduced in fat-1 mice. The analyses of lipid metabolomics showed the high level of 18-hydroxyeicosapentaenoate in fat-1 mice, which was derived from EPA and was metabolized to anti-inflammatory product named resolvin E3 (RvE3). We finally showed that the administration of RvE3 to LPS-exposed pregnant wild type mice lowered the incidence of preterm birth. Our data suggest that RvE3 could be a potential new therapeutic for the prevention of preterm birth.

Influence of infection during pregnancy on fetal development

Infection by bacteria, viruses, and parasites may lead to fetal death, organ injury, or limited sequelae depending on the pathogen. Here, we consider the role of infection during pregnancy in fetal development including placental development and function, which can lead to fetal growth restriction. The classical group of teratogenic pathogens is referred to as 'TORCH' (Toxoplasma gondii, others like Treponema pallidum, rubella virus, cytomegalovirus, and herpes simplex virus) but should include a much broader group of pathogens including Parvovirus B19, Varicella zoster virus, and Plasmodium falciparum to name a few. In this review, we describe the influence of different infections in utero on fetal development and the short- and long-term outcomes for the neonate. In some cases, the mechanisms used by these pathogens to disrupt fetal development are well known. Bacterial infection of the developing fetal lungs and brain begins with an inflammatory cascade resulting in cytokine injury and oxidative stress. For some pathogens like P. falciparum, the mechanisms involve oxidative stress and apoptosis to disrupt placental and fetal growth. An in utero infection may also affect the long-term health of the infant; in many cases, a viral infection in utero increases the risk of developing type 1 diabetes in childhood. Understanding the varied mechanisms employed by these pathogens may enable therapies to attenuate changes in fetal development, decrease preterm birth, and improve survival.

Placental pathology in full-term infants with hypoxic-ischemic neonatal encephalopathy and association with magnetic resonance imaging pattern of brain injury

OBJECTIVE

To investigate the relationship between placental pathology and pattern of brain injury in full-term infants with neonatal encephalopathy after a presumed hypoxic-ischemic insult.

STUDY DESIGN

The study group comprised full-term infants with neonatal encephalopathy subsequent to presumed hypoxia-ischemia with available placenta for analysis who underwent cerebral magnetic resonance imaging (MRI) within the first 15 days after birth. Macroscopic and microscopic characteristics of the placenta were assessed. The infants were classified according to the predominant pattern of brain injury detected on MRI: no injury, predominant white matter/watershed injury, predominant basal ganglia and thalami (BGT) injury, or white matter/watershed injury with BGT involvement. Maternal and perinatal clinical factors were recorded.

RESULTS

Placental tissue was available for analysis in 95 of 171 infants evaluated (56%). Among these 95 infants, 34 had no cerebral abnormalities on MRI, 27 had white matter/watershed injury, 18 had BGT injury, and 16 had white matter/watershed injury with BGT involvement. Chorioamnionitis was a common placental finding in both the infants without injury (59%) and those with white matter/BGT injury (56%). On multinomial logistic regression analysis, white matter/watershed injury with and without BGT involvement was associated with decreased placental maturation. Hypoglycemia was associated with an increased risk of the white matter/BGT injury pattern (OR,5.4; 95% CI, 1.4-21.4). The BGT injury pattern was associated with chronic villitis (OR, 12.7; 95% CI, 2.4-68.7). A placental weight <10th percentile appeared to be protective against brain injury, especially for the BGT pattern (OR, 0.1; 95% CI, 0.01-0.7).

CONCLUSION

Placental weight <10th percentile was mainly associated with normal cerebral MRI findings. Decreased placental maturation and hypoglycemia <2.0 mmol/L were associated with increased risk of white matter/watershed injury with or without BGT involvement. Chronic villitis was associated with BGT injury irrespective of white matter injury.

Effect of dexamethasone administered with magnesium sulfate on inflammation-mediated degradation of the blood-brain barrier using an in vitro model

Patients at risk for preterm delivery are frequently administered both antenatal steroids for fetal maturation and magnesium sulfate for neuroprotection. In this study, we investigate whether steroids coadministered with magnesium sulfate preserve blood-brain barrier integrity in neuroinflammation. Human umbilical vein endothelial cells were grown in astroglial conditioned media in a 2-chamber cell culture apparatus. Treatment with tumor necrosis factor-α (TNF-α) or catalytically active recombinant matrix metalloproteinase 9 (MMP-9) simulated neuroinflammation. Membrane integrity was assessed by zona occludens 1 (ZO-1) immunoreactivity, permeability to fluorescently conjugated dextran, and transendothelial electrical resistance (TEER). The TNF-α and MMP-9 treatment increased the rate of dextran transit, decreased TEER, and decreased ZO-1 immunoreactivity at junctional interfaces. Dexamethasone pretreatment alone or in combination with 0.5 mmol/L magnesium sulfate preserved monolayer integrity after inflammatory insult. Magnesium sulfate alone was not protective. This study supports a possible interaction between steroids and magnesium in neuroprotection.

Risk of early-onset neonatal infection with maternal infection or colonization: a global systematic review and meta-analysis

BACKGROUND

Neonatal infections cause a significant proportion of deaths in the first week of life, yet little is known about risk factors and pathways of transmission for early-onset neonatal sepsis globally. We aimed to estimate the risk of neonatal infection (excluding sexually transmitted diseases [STDs] or congenital infections) in the first seven days of life among newborns of mothers with bacterial infection or colonization during the intrapartum period.

METHODS AND FINDINGS

We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, and the World Health Organization Regional Databases for studies of maternal infection, vertical transmission, and neonatal infection published from January 1, 1960 to March 30, 2013. Studies were included that reported effect measures on the risk of neonatal infection among newborns exposed to maternal infection. Random effects meta-analyses were used to pool data and calculate the odds ratio estimates of risk of infection. Eighty-three studies met the inclusion criteria. Seven studies (8.4%) were from high neonatal mortality settings. Considerable heterogeneity existed between studies given the various definitions of laboratory-confirmed and clinical signs of infection, as well as for colonization and risk factors. The odds ratio for neonatal lab-confirmed infection among newborns of mothers with lab-confirmed infection was 6.6 (95% CI 3.9-11.2). Newborns of mothers with colonization had a 9.4 (95% CI 3.1-28.5) times higher odds of lab-confirmed infection than newborns of non-colonized mothers. Newborns of mothers with risk factors for infection (defined as prelabour rupture of membranes [PROM], preterm <37 weeks PROM, and prolonged ROM) had a 2.3 (95% CI 1.0-5.4) times higher odds of infection than newborns of mothers without risk factors.

CONCLUSIONS

Neonatal infection in the first week of life is associated with maternal infection and colonization. High-quality studies, particularly from settings with high neonatal mortality, are needed to determine whether targeting treatment of maternal infections or colonization, and/or prophylactic antibiotic treatment of newborns of high risk mothers, may prevent a significant proportion of early-onset neonatal sepsis. Please see later in the article for the Editors' Summary.

Prenatal and postnatal inflammation in relation to cortisol levels in preterm infants at 18 months corrected age

OBJECTIVE

To examine whether early inflammation is related to cortisol levels at 18 months corrected age (CA) in children born very preterm.

STUDY DESIGN

Infants born ≤ 32 weeks of gestational age were recruited in the neonatal intensive care unit (NICU), and placental histopathology, magnetic resonance imaging (MRI) and chart review were obtained. At 18 months CA, developmental assessment and collection of three salivary cortisol samples were carried out. Generalized least squares was used to analyze data from 85 infants providing 222 cortisol samples.

RESULT

Infants exposed to chorioamnionitis with funisitis had a significantly different pattern of cortisol across the samples compared with infants with chorioamnionitis alone or no prenatal inflammation (F(4, 139)=7.3996, P<0.0001). Postnatal infections, necrotizing enterocolitis and chronic lung disease were not significantly associated with the cortisol pattern at 18 months CA.

CONCLUSION

In children born very preterm, prenatal inflammatory stress may contribute to altered programming of the hypothalamic-pituitary-adrenal (HPA) axis.

The expression of thioredoxin-1 in preterm delivery placenta

Preterm delivery (PTD) is the leading cause of infant mortality and morbidity. However, the mechanism at the molecular level is still unknown. Placental inflammatory response and oxidative stress are associated with PTD. Thioredoxin-1 (TRX-1) regulates oxidative stress, inflammation, and the activities of transcription factors.

OBJECTIVES

The objective was to detect in placental tissues the expressions of TRX-1 and the TRX-1-related molecules: tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2), thioredoxin-1-binding protein-2 (TBP-2), hypoxia inducible transcription factor 1α (HIF-1α), and forkhead box protein O3A (FoxO3A).

METHODS

PTD was defined as gestation of <37 weeks and term delivery (TD) as ≥37 weeks. The expressions of TRX-1 and TRX-1-related molecules were examined in placental tissues by real-time polymerase chain rection and western blot.

RESULTS

The expressions of TRX-1, TNF-α, COX-2, HIF-1α, and FoxO3A in the placenta of PTD were significantly higher as compared with TD, but no difference was observed in TBP-2 expression.

DISCUSSION

These results indicate that TRX-1 may be adaptively induced by the effects of inflammation and oxidative stress, suggesting protective roles for TRX-1 against these effects in the placenta of PTD.

Intrapregnancy non-surgical periodontal treatment and pregnancy outcome: a randomized controlled trial

BACKGROUND

The purpose of the present study is to investigate the potential link between maternal periodontitis and pregnancy outcomes, including preterm birth (<37 weeks) and low birth weight (<2,500 g).

METHODS

Ninety nine pregnant females with mild/moderate periodontitis were randomly allocated to a control (n = 50) or test (n = 49) group. Test group participants received intrapregnancy non-surgical periodontal treatment, whereas this was deferred until after delivery for controls. Demographic and baseline clinical data were obtained for all participants at initial assessment pretreatment. Clinical data were rerecorded for test participants at review 8 weeks after treatment. Birth outcomes were completed at delivery by midwives who also collected cord blood samples when possible; the latter were analyzed to determine the presence/levels of cytokines interleukin (IL)-1β, IL-6, and IL-8. All data were analyzed on an intention-to-treat basis using appropriate statistical tests.

RESULTS

Random allocation of participants resulted in well-balanced control and test groups. All test group participants and all but one control participant gave birth to a live infant. No significant differences were detected between control and test groups with regard to birth outcome measures of birth weight and gestational age or in relation to cytokine prevalence/levels.

CONCLUSION

Intrapregnancy non-surgical periodontal treatment, completed at 20 to 24 weeks, did not reduce the risk of preterm, low-birth-weight delivery in this population.

Foreskin analysis of circumcised boys with and without previous topical corticosteroid

Problems with the foreskin are common reasons for pediatric surgery consultations. We collected the foreskin of 40 patients for 2 years and these samples were divided into groups with and without previous topical corticosteroid. We carried out histochemical hematoxylin & eosin and Picrosirius analyses of the foreskin. Collagen fibers and inflammatory infiltrate was higher in samples from patients who had complications related to phimosis. Fibrosis was higher in patients who used topical corticosteroid. A histopathologic study of the foreskin may provide an additional analysis of patients undergoing circumcision and it can also improve the accuracy of surgical indication.

Umbilical blood biomarkers for predicting early-onset neonatal sepsis

BACKGROUND

Since the 1990s, finding the most efficient markers or combinations as predictors of early-onset neonatal sepsis has been the hot topic of studies. But there is no review of such biomarkers detected in umbilical blood at birth. By comparing clinical values of common inflammatory markers detected in cord blood shortly after birth, in this study we tried to find the most performing one or the most efficient combination that might be potentially used in birth room, as the earliest predictor of early-onset neonatal sepsis.

DATA SOURCES

We searched PubMed and Elsevier's Web of Science for studies evaluating cord blood inflammatory markers in relation to early-onset neonatal sepsis.

RESULTS

Among C-reactive protein (CRP), procalcitonin (PCT), IL-6, IL-8, TNF-α and IL-1β, none of them could be used individually to establish or exclude the diagnosis of early-onset neonatal sepsis, but PCT, IL-6 and IL-8 have great superiority to CRP, TNF-α and IL-1β. When combined with other hematological markers and clinical observation, the clinical reliability of PCT, IL-6 and IL-8 could be improved. Prolonging the sample collection time window seems to have a positive effect on the clinical utility of IL-6 and IL-8.

CONCLUSIONS

More researches focusing on the combination of different umbilical cord biomarkers in different clinical settings are needed to achieve clearer conclusions. Multi-center, large-sized analysis, especially examining groups of cytokines, is also expected.

Acute histologic chorioamnionitis at term: nearly always noninfectious

Background

The link between histologic acute chorioamnionitis and infection is well established in preterm deliveries, but less well-studied in term pregnancies, where infection is much less common.

Methodology/Principal Findings

We conducted a secondary analysis among 195 low-risk women with term pregnancies enrolled in a randomized trial. Histologic and microbiologic evaluation of placentas included anaerobic and aerobic cultures (including mycoplasma/ureaplasma species) as well as PCR. Infection was defined as ≥1,000 cfu of a single known pathogen or a ≥2 log difference in counts for a known pathogen versus other organisms in a mixed culture. Placental membranes were scored and categorized as: no chorioamnionitis, Grade 1 (subchorionitis and patchy acute chorioamnionitis), or Grade 2 (severe, confluent chorioamnionitis). Grade 1 or grade 2 histologic chorioamnionitis was present in 34% of placentas (67/195), but infection was present in only 4% (8/195). Histologic chorioamnionitis was strongly associated with intrapartum fever >38°C [69% (25/36) fever, 26% (42/159) afebrile, P<.0001]. Fever occurred in 18% (n = 36) of women. Most febrile women [92% (33/36)] had received epidural for pain relief, though the association with fever was present with and without epidural. The association remained significant in a logistic regression controlling for potential confounders (OR = 5.8, 95% CI = 2.2,15.0). Histologic chorioamnionitis was also associated with elevated serum levels of interleukin-8 (median = 1.3 pg/mL no histologic chorioamnionitis, 1.5 pg/mL Grade 1, 2.1 pg/mL Grade 2, P = 0.05) and interleukin-6 (median levels = 2.2 pg/mL no chorioamnionitis, 5.3 pg/mL Grade 1, 24.5 pg/mL Grade 2, P = 0.02) at admission for delivery as well as higher admission WBC counts (mean = 12,000cells/mm³ no chorioamnionitis, 13,400cells/mm³ Grade 1, 15,700cells/mm³ Grade 2, P = 0.0005).

Conclusion/Significance

Our results suggest histologic chorioamnionitis at term most often results from a noninfectious inflammatory process. It was strongly associated with fever, most of which was related to epidural used for pain relief. A more ‘activated’ maternal immune system at admission was also associated with histologic chorioamnionitis.

Cytomegalovirus infection during pregnancy with maternofetal transmission induces a proinflammatory cytokine bias in placenta and amniotic fluid

Congenital infection with cytomegalovirus (CMV) can induce immune responses and placental damage. By use of immunoassay panels, 27 cytokines were assessed in midtrimester amniotic fluid from 8 patients with congenital CMV, in midtrimester sera from 12 pregnant women with primary CMV infection, and in amniotic fluid and serum from uninfected maternal controls. Levels of the cytokines tumor necrosis factor α, interleukin 1β, interleukin 12, and interleukin 17; the chemokines CCL2, CCL4, and CXCL10; and the growth factors granulocyte-macrophage colony-stimulating factor and platelet-derived growth factor bb were significantly elevated in amniotic fluid from congenital CMV patients (P < .01). Only CXCL10 was significantly higher in sera from CMV-infected pregnant women. CMV infection during pregnancy is associated with a shift in cytokine expression toward a proinflammatory state.

A clinic-biological score for diagnosing early-onset neonatal infection in critically ill preterm infants

OBJECTIVE

To identify the best combination of serum cytokines and clinical parameters to diagnose rapidly early-onset neonatal infection (EONI) in critically ill preterm infants. At birth, most critically ill neonates are receiving broad-spectrum antibiotics pending bacterial culture results, because distinguishing infected from noninfected infants at birth is difficult.

DESIGN

Prospective study.

SETTING

Neonatal intensive care unit in a tertiary care hospital.

PATIENTS

Two hundred thirteen infants, born before 33 wks' gestation, admitted to the neonatal intensive care unit within 6 hrs of life with a presumptive diagnosis of EONI.

INTERVENTION

A presumptive diagnosis of EONI was associated with a 300-μL blood sample to measure six cytokine (interleukin [IL]-1β, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor-α) concentrations, using the cytometric bead array technique.

MEASUREMENTS AND MAIN RESULTS

Of the 213 infants included, 31 had a definite or possible EONI and 182 were not infected. Concentrations of IL-6, IL-8, and IL-10 were significantly increased in infected neonates, in comparison with infants without EONI. In contrast, IL-1β, IL-12, and tumor necrosis factor-α concentrations were not. Logistic regression analyses were performed to construct multivariate predictive models that could distinguish infected from noninfected infants at birth. A clinical score was based on three parameters independently associated with EONI (i.e., interval of >12 hrs between the membranes rupture and delivery, prenatal maternal colonization and mechanical ventilation at birth). This score was compared with scores including clinical parameters and serum cytokines, alone or in combination. The best predictive model combined the three clinical parameters, IL-6 (positive threshold, 300 pg/mL) and IL-8 (positive threshold, 300 pg/mL) concentrations.

CONCLUSION

A predictive model combining serum IL-6 and IL-8 measurements and selected clinical variables could distinguish infected from noninfected preterm infants at birth and should help the clinician in reducing or shortening the unnecessary use of antibiotics.

Pharmacological inhibition of inflammatory pathways for the prevention of preterm birth

The major cause of spontaneous preterm birth (sPTB) at less than 32 weeks of gestation is intrauterine inflammation as a consequence of colonisation of the gestational membranes by pathogenic microorganisms which trigger activation of the local innate immune system. This results in release of inflammatory mediators, leukocytosis (chorioamnionitis), apoptosis, membrane rupture, cervical ripening and onset of uterine contractions. Recent PCR evidence suggests that in the majority of cases of inflammation-driven preterm birth, microorganisms are present in the amniotic fluid, but these are not always cultured by standard techniques. The nature of the organism and its cell wall constituents, residence time in utero, microbial load, route of infection and extent of tissue penetration are all factors which can modulate the timing and magnitude of the inflammatory response and likelihood of progression to sPTB. Administration of anti-inflammatory drugs could be a viable therapeutic option to prevent sPTB and improve fetal outcomes in women at risk of intrauterine inflammation. Preventing fetal inflammation via administration of placenta-permeable drugs could also have significant perinatal benefits in addition to those related to extension of gestational age, as a fetal inflammatory response is associated with a range of significant morbidities. A number of potential drugs are available, effective against different aspects of the inflammatory process, although the pathways actually activated in spontaneous preterm labour have yet to be confirmed. Several pharmacological candidates are discussed, together with clinical and toxicological considerations associated with administration of anti-inflammatory agents in pregnancy.

Relationship Between Neonatal Blood Protein Concentrations and Placenta Histologic Characteristics in Extremely Low GA Newborns

Amniotic fluid infection with chorioamnionitis is associated with increased risks of morbidity and mortality in children born prematurely. These risks depend on the presence of a fetal inflammatory response. We measured the concentrations of 25 proteins in the blood of 871 infants born before the 28th wk of gestation and examined their placentas for acute inflammation. Newborns who had inflammatory lesions of the placenta were much more likely than their peers (p < 0.01) to have elevated blood concentrations of cytokines (IL-1β, IL-6, and TNF-α), chemokines (IL-8, MIP-1β, RANTES, and I-TAC), adhesion molecules (ICAM-1, ICAM-3, and E-selectin), matrix metalloproteinases (MMP-1 and MMP-9), the angiogenic inflammatory factor VEGF and its receptor VEGF-R2, and acute phase proteins (SAA and CRP) during the first 3 d after birth. In contrast, newborns with poor placental perfusion had lower levels of inflammatory proteins (p < 0.01; IL-6, RANTES, ICAM-1, ICAM-3, VCAM-1, E-selectin, MMP-1, MMP-9, MPO, and VEGF). An inverse pattern was found between newborn levels of VEGF and its competitive inhibitor VEGF-R1 in both the inflamed and poorly perfused placenta categories. These results confirm the predictive value of placental histology for the presence or absence of elevated inflammatory response in newborns.

Maternal Schistosomiasis japonica is associated with maternal, placental, and fetal inflammation

Schistosomes infect ∼40 million women of childbearing age and result in the elaboration of proinflammatory cytokines that have been implicated in fetal growth restriction. In murine models and two observational studies in humans, schistosome infection during pregnancy was associated with reduced birth weight, although a recent treatment trial in Schistosoma mansoni did not detect this association. We conducted an observational study among 99 pregnant women living in an area of Schistosoma japonicum endemicity in the Philippines. We enrolled women at 32 weeks gestation and measured S. japonicum and geohelminth infection intensity. We collected maternal peripheral blood at 32 weeks gestation and placental and cord blood at delivery to assess inflammatory status. At delivery, we collected a placental-tissue sample and measured birth weight. In multivariate models adjusted for geohelminths, maternal schistosomiasis was associated with increased levels of inflammatory cytokines in maternal peripheral (tumor necrosis factor alpha [TNF-α] and interleukin 10 [IL-10]), placental (TNF-α, IL-6, TNF-α receptor II [RII], and IL-1β), and cord (IL-1β and TNF-α RII) blood, as well as acute subchorionitis and increased TNF-α production by syncytiotrophoblasts assessed by immunohistochemistry (all P < 0.05). After adjusting for confounders, placental IL-1β, and TNF-α production by syncytiotrophoblasts was independently associated with decreased birth weight (both P < 0.05). Our data indicate that maternal schistosomiasis results in a proinflammatory signature that is detectable in maternal, placental, and fetal compartments, and a subset of these responses are associated with decreased birth weight. This potential mechanistic link between maternal schistosomiasis and poor birth outcomes will contribute to the debate regarding treatment of maternal schistosome infections.

Maternal interleukin-6 (-174) C/C polymorphism is associated with chorioamnionitis and cystic periventricular leucomalacia of the preterm infant

OBJECTIVE

To evaluate the association between maternal interleukin (IL)-6 G(-174)C polymorphism and cystic periventricular leukomalacia (cPVL) of the preterm newborn.

STUDY DESIGN

After searching a local database, we recruited 132 preterm infants with diagnosis of cPVL, 44 Caucasian mothers were also recruited to participate in this candidate gene-association study at a single teritary care center. Data related to maternal IL-6 G(-174)C polymorphisms were compared with 41 controls, and furthermore compared with data from umbilical cord blood samples from a consecutive birth cohort of 395 healthy newborns, and published data from Caucasian populations including 1104 adults, respectively. In addition, subgroup analysis was performed in cases with either history of preterm premature rupture of the membranes (PPROM) or clinical chorioamnionitis (CCA). IL-6 genotyping was performed using an allele-specific polymerase chain reaction technique.

RESULT

Frequencies of the IL-6 G(-174)C polymorphisms did not differ between cases (GG, 29.5%; GC, 54.5% and CC, 15.9%) and controls (GG, 34.2; GC, 51.2 and CC, 14.6%). Subgroup analysis of 31 cases with history of PPROM (GG, 25.8; GC, 54.8 and CC 19.4%) and controls did not reveal significant differences, but a significantly higher frequency of the CC genotype was found in 23 cases with a history of CCA (34.8%) compared with controls by either univariate (P=0.032; odds ratio 3.11, 95% confidence interval (CI) 1.11 to 8.68) or multivariate analysis (P=0.049, odds ratio 2.54, 95% CI 1.01 to 6.45). These data were confirmed by a comparing the CC genotype frequency to 395 term controls (CC 14.7%, P=0.005) and to the mean CC genotype frequency of 1104 Caucasian adults (CC 15.6%, P<0.0001).

CONCLUSION

Frequencies of the IL-6 G(-174)C polymorphisms did not differ between groups. Subgroup analysis revealed an association of the CC genotype with CCA and cPVL in the preterm newborn.

Human labor is associated with reduced decidual cell expression of progesterone, but not glucocorticoid, receptors

CONTEXT

Unchanging plasma progesterone (P4) levels suggest that human labor is initiated by reduced P4 receptor (PR) expression, which elicits functional P4 withdrawal. The glucocorticoid receptor (GR) is also implicated in this process.

OBJECTIVE

Our objective was to compare PR and GR staining in human decidual cells (DCs) and interstitial trophoblasts (ITs) of gestational age-matched pre- and postcontraction specimens and to evaluate steroid effects on PR and GR expression in human DC cultures.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Decidua basalis and parietalis sections were immunostained for PR or GR and then for the cytoplasmic DC and IT markers vimentin and cytokeratin. Western blotting measured PR and GR levels in nuclear extracts of cultured leukocyte-free term DCs after incubation with estradiol-17beta (E2) with or without medroxyprogesterone acetate (MPA).

RESULTS

PR histological scores (HSCOREs) were significantly higher in DC nuclei from pre- vs. post-uterine-contraction decidua basalis and parietalis sections with PR immunostaining absent from ITs. In contrast, immunoreactive GR was localized in IT and DC nuclei. GR HSCORES were significantly higher in ITs than DCs but similar in pre- vs. post-uterine-contraction specimens. In term DC monolayers, PR-A and PR-B were enhanced by E2 and inhibited by MPA, whereas E2 plus MPA produced intermediate PR expression. The GR was constitutively expressed.

CONCLUSIONS

In post- vs. pre-uterine-contraction specimens, significantly lower HSCOREs in DC nuclei, but not IT, and unchanging GR levels in DCs and ITs suggest that functional P4 withdrawal may occur in DCs and is unlikely to involve the GR. Nuclear extracts from DC monolayer cultures express steroid-regulated PR-A and PR-B and constitutive GR.

Reduced mortality and increased BPD with histological chorioamnionitis and leukocytosis in very-low-birth-weight infants

OBJECTIVE

To investigate the association between leukocytosis, mortality and bronchopulmonary dysplasia (BPD) in very-low-birth-weight infants (VLBW) born to mothers with histological chorioamnionitis.

STUDY DESIGN

A retrospective cohort study from a single level 3 neonatal intensive care unit. The study sample included infants born to mothers with histological chorioamnionitis (n=252). Total white blood cells (WBCs) after birth were measured. Leukocytosis was defined as a total WBC count >30 000 per mm(3) in the first 2 days of life. Outcomes investigated included BPD and death. Both unadjusted and multivariable analyses were carried out.

RESULT

After controlling for potential confounding variables, infants who developed a leukocytosis after birth had increased odds of BPD (4.6, 95% confidence interval (95% CI): 2.0 to 10.3), but decreased odds of death (0.3, 95% CI: 0.1 to 0.90).

CONCLUSION

In our population of VLBW infants born to mothers with histological chorioamnionitis, leukocytosis after birth is associated with a decrease in mortality but an increase in BPD.

Chorioamnionitis--a complex pathophysiologic syndrome

Chorioamnionitis, inflammation of the amniochorionic membrane (fetal membranes) is a very common disease but a complex syndrome associated with pregnancy. It presents a clinical impasse due to lack of knowledge of specific etiologies associated with this condition making confident clinical interventions difficult. Recent reports provide insight into genetic, epigenetic, behavioral, psychosocial, molecular and pathophysiological factors that are associated with chorioamnionitis. However, a coordinated approach in understanding causality and lack of early indicators (clinical and biomarkers) has hampered gaining knowledge about the disease status preventing proper intervention. Several reviews have provided in-depth analysis of the histologic and clinical evidence associated with chorioamnionitis. In this review, we provide a novel perspective on chorioamnionitis based on recent evidences from scientific literature on inflammation, apoptosis and genetics.

Comparison of markers for fetal inflammatory response syndrome: fetal blood interleukin-6 and neonatal urinary beta(2)-microglobulin

AIM

Chronic lung disease (CLD) is a major component in the morbidity of premature infants suffering from fetal inflammatory response (FIRS). The aim of the present study was to compare the value of measuring neonatal urinary beta(2)-microglobulin (beta(2)-MG) levels with fetal blood interleukin (IL)-6 levels in premature infants at risk of developing CLD.

METHODS

Premature infants (gestational age <30 weeks) without CLD (n = 19) and with CLD (n = 10) were enrolled. We measured IL-6 levels in umbilical cord blood and beta(2)-MG levels in urine obtained within 48 h after birth.

RESULTS

IL-6 and beta(2)-MG levels were significantly higher in infants who developed CLD than in those who did not (median IL-6, 54.7 vs 7.6 pg/mL; P < 0.005; beta(2)-MG 17.7 vs 9.3 x 10(4) microg/gCr; P < 0.05). The sensitivity and negative predictive value of beta(2)-MG at the cut-off value at 10.0 x 10(4) microg/gCr (0.90 and 0.92) were comparable to IL-6 at 16 pg/mL (0.90 and 0.94).

CONCLUSION

We suggest that measuring urinary beta(2)-MG in premature infants soon after birth can monitor FIRS and may provide information on the risk of subsequent CLD development that is as clinically important as information derived from umbilical cord blood IL-6.