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

Polymorphisms in the calcium voltage-gated channel subunit Alpha1 D (CACNA1D) gene are associated with spontaneous preterm birth in Taiwanese women

PURPOSE

Calcium signaling is essential for immune function, myometrial contractions, and hormone secretion, all of which contribute to preterm birth. In this study, we investigated the associations of 3 single-nucleotide polymorphisms (SNPs) in CACNA1D gene, which encodes the Cav1.3 calcium channel, with the risk of spontaneous preterm birth (sPTB).

METHODS

A hospital-based case-control study was conducted with 112 women of sPTB and 1120 term control women. Three CACNA1D SNPs (rs9810888 T/G, rs1045958 C/T, and rs881883 G/A) were genotyped.

RESULTS

The T/G genotype of the CACNA1D rs9810888 SNP was associated with a reduced risk of sPTB (odds ratio: 0.61, 95 % confidence interval: 0.41-0.91, P = 0.01, Pc = 0.03). However, no significant associations were observed for the other 2 SNPs. Haplotype analysis revealed no significant differences between the case and control groups.

CONCLUSION

Our findings suggest that the intronic rs9810888 T/G variant of CACNA1D gene protects against sPTB in Taiwanese women.

Using transcriptomic signatures to elucidate individual and mixture effects of inorganic arsenic and manganese in human placental trophoblast HTR-8/SVneo cells

Prenatal exposure to the toxic metal inorganic arsenic (iAs) is associated with adverse pregnancy and fetal growth outcomes. These adverse outcomes are tied to physiological disruptions in the placenta. Although iAs co-occurs in the environment with other metals such as manganese (Mn), there is a gap in the knowledge of the effects of metal mixtures on the placenta. To address this, we exposed human placental trophoblast cells to iAs, Mn, and an iAs-Mn mixture at 3 concentrations and evaluated transcriptome-wide gene expression and placental migration. We hypothesized that co-exposure to iAs-Mn in a mixture would result in a synergistic/enhanced transcriptomic effect compared to either metal alone. We also anticipated that genes involved in inflammatory or immune-related pathways would be differentially expressed in relation to the mixture compared to single-metals. The results highlight that iAs exposure alone had a stronger genomic response than Mn exposure, with 2-fold the number of differentially expressed genes (DEGs). When analyzing DEGs present across all concentrations of study, the iAs-Mn mixture resulted in the greatest number of DEGs. The results highlight that iAs exposure alone influences the expression of toll-like receptor-initiated response pathways including Triggering Receptor Expressed on Myeloid Cells-1. Exposure to Mn alone influenced the expression of Nicotinamide adenine dinucleotide biosynthesis pathways. In contrast, exposure to the iAs-Mn mixtures resulted in altered expression of inflammatory and immune response-related pathways, including the Nuclear factor erythroid 2-related factor 2 (NRF2)-mediated oxidative stress response pathway. Migration was unaffected by iAs, Mn, or the iAs-Mn mixture. These findings provide novel toxicogenomic insights into iAs- and Mn-induced placental transcriptomic dysregulations at environmentally relevant concentrations, with implications that in utero exposure to metal mixtures can influence inflammatory and immune pathways within the placenta.

Galectin-1 Elicits a Tissue-Specific Anti-Inflammatory and Anti-Degradative Effect Upon LPS-Induced Response in an Ex Vivo Model of Human Fetal Membranes Modeling an Intraamniotic Inflammation

PROBLEM

Intrauterine infection is one of the most jeopardizing conditions associated with adverse outcomes, including preterm birth; however, multiple tolerance mechanisms operate at the maternal-fetal interface to avoid the rejection of the fetus. Among the factors that maintain the uterus as an immunoprivileged site, Galectin-1 (Gal-1), an immunomodulatory glycan-binding protein secreted by the maternal-fetal unit, is pivotal in promoting immune cell homeostasis. This work aimed to evaluate the role of Gal-1 during a lipopolysaccharide (LPS)-induced-inflammatory milieu.

METHOD OF STUDY

Using an ex vivo culture with two independent compartments, human fetal membranes at term were pretreated with 40 and 80 ng/mL of Gal-1, then to reproduce an intraamniotic inflammation, the fetal side of membranes was stimulated with 500 ng/mL of LPS for 24 h. The concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, monocyte chemoattractant protein (MCP1), macrophage inflammatory protein (MIP1) α, regulated upon activation normal T cell expressed and secreted (RANTES), and matrix metalloproteinase (MMP)-9 were measured in both amnion and choriodecidua compartments.

RESULTS

In a tissue-specific fashion profile, pretreatment with the physiologic concentration of Gal-1 significantly diminished the LPS-dependent secretion of TNF-α, IL-1β, Il-6, MCP1, MIP1α, RANTES, and MMP-9.

CONCLUSION

Gal-1 elicits an anti-inflammatory effect on the human fetal membranes stimulated with LPS, which supports the hypothesis that Gal-1 is part of the immunomodulatory mechanisms intended to stop the harmful effect of inflammation of the maternal-fetal interface.

Preterm birth as a determinant of neurodevelopment and cognition in children (PRENCOG): protocol for an exposure-based cohort study in the UK

INTRODUCTION

Preterm birth (PTB) is strongly associated with encephalopathy of prematurity (EoP) and neurocognitive impairment. The biological axes linking PTB with atypical brain development are uncertain. We aim to elucidate the roles of neuroendocrine stress activation and immune dysregulation in linking PTB with EoP.

METHODS AND ANALYSIS

PRENCOG (PREterm birth as a determinant of Neurodevelopment and COGnition in children: mechanisms and causal evidence) is an exposure-based cohort study at the University of Edinburgh. Three hundred mother-infant dyads comprising 200 preterm births (gestational age, GA <32 weeks, exposed) and 100 term births (GA >37 weeks, non-exposed), will be recruited between January 2023 and December 2027. We will collect parental and infant medical, demographic, socioeconomic characteristics and biological data which include placental tissue, umbilical cord blood, maternal and infant hair, infant saliva, infant dried blood spots, faecal material, and structural and diffusion MRI. Infant biosamples will be collected between birth and 44 weeks GA.EoP will be characterised by MRI using morphometric similarity networks (MSNs), hierarchical complexity (HC) and magnetisation transfer saturation imaging (MTsat). We will conduct: first, multivariable regressions and statistical association assessments to test how PTB-associated risk factors (PTB-RFs) relate to MSNs, HC and or MTsat; second, structural equation modelling to investigate neuroendocrine stress activation and immune dysregulation as mediators of PTB-RFs on features of EoP. PTB-RF selection will be informed by the variables that predict real-world educational outcomes, ascertained by linking the UK National Neonatal Research Database with the National Pupil Database.

ETHICS AND DISSEMINATION

A favourable ethical opinion has been given by the South East Scotland Research Ethics Committee 02 (23/SS/0067) and NHS Lothian Research and Development (2023/0150). Results will be reported to the Medical Research Council, in scientific media, via stakeholder partners and on a website in accessible language (https://www.ed.ac.uk/centre-reproductive-health/prencog).

Maternal immunity shapes biomarkers of germinal center development in HIV-exposed uninfected infants

Introduction

HIV-exposed uninfected (HEU) infants exhibit elevated pro-inflammatory biomarkers that persist after birth. However, comprehensive assessments of bioprofiles associated with immune regulation and development in pregnant women with HIV (PWH) and HEU infants has not been performed. Maternal immunity in PWH may be imprinted on their HEU newborns, altering immune bioprofiles during early immune development.

Methods

Cryopreserved paired plasma samples from 46 HEU infants and their mothers enrolled in PACTG 316, a clinical trial to prevent perinatal HIV-1 transmission were analyzed. PWH received antiretrovirals (ARV) and had either fully suppressed or unsuppressed viral replication. Maternal blood samples obtained during labor and infant samples at birth and 6 months were measured for 21 biomarkers associated with germinal centers (GC), macrophage activation, T-cell activation, interferon gamma (IFN-γ)-inducible chemokines, and immune regulatory cytokines using Mesoscale assays. Pregnant women without HIV (PWOH) and their HIV unexposed uninfected (HUU) newborns and non-pregnant women without HIV (NPWOH) served as reference groups. Linear regression analysis fitted for comparison among groups and adjusted for covariant(s) along with principal component analysis performed to assess differences among groups.

Results

Compared with NPWOH, PWOH displayed higher levels of GC, macrophage, and regulatory biomarkers. PWH compared to PWOH displayed elevated GC, T cell activation, and IFN-γ-inducible chemokines biomarkers at delivery. Similar to their mothers, HEU infants had elevated GC, macrophage, and IFN-γ-inducible chemokines, as well as elevated anti-inflammatory cytokines, IL-10 and IL-1RA. Across all mother/newborn dyads, multiple biomarkers positively correlated, providing further evidence that maternal inflammation imprints on newborn bioprofiles. By 6 months, many HEU biomarkers normalized to levels similar to HUU infants, but some GC and inflammatory biomarkers remained perturbed. Bioprofiles in PWH and HEU infants were similar regardless of the extent of maternal viral suppression by ARV.

Conclusions

GC immune pathways are perturbed in HEU newborns, but immune regulatory responses down regulate inflammation during early infancy, indicating a transient inflammatory effect. However, several GC biomarkers that may alter immune development remain perturbed.

Recombinant fragment of human surfactant protein D to prevent neonatal chronic lung disease (RESPONSE): a protocol for a phase I safety trial in a tertiary neonatal unit

INTRODUCTION

Chronic respiratory morbidity from bronchopulmonary dysplasia (BPD) remains the most common complication of preterm birth and has consequences for later respiratory, cardiovascular and neurodevelopmental outcomes. The early phases of respiratory illness are characterised by rapid consumption of endogenous surfactant and slow replenishment. Exogenous surfactant is routinely administered to infants born before 28 weeks of gestation as prophylaxis. Endogenous surfactant includes four proteins, known as surfactant proteins (SPs) A, B, C and D. Current bovine-derived and porcine-derived surfactant preparations only contain SPs B and C. SP-D has a key role in lung immune homeostasis as part of the innate immune system. Laboratory studies using recombinant SP-D have demonstrated reduced inflammation, which may be a pathway to reducing the associated morbidity from BPD. RESPONSE uses a recombinant fragment of human SP D (rfhSP-D), in a phase I safety and dose-escalation trial as the first stage in determining its effect in humans.

METHODS AND ANALYSIS

This is a single-centre, dose-escalation, phase I safety study aiming to recruit 24 infants born before 30 weeks gestation with respiratory distress syndrome. In addition to routine surfactant replacement therapy, participants will receive three doses of rfhSP-D via endotracheal route at either 1 mg/kg, 2 mg/kg or 4 mg/kg. The study uses a Bayesian continual reassessment method to make dose escalation decisions. Dose-limiting events (DLE) in this trial will be graded according to the published Neonatal Adverse Event Severity Score. The primary outcome of this study is to evaluate the safety profile of rfhSP-D across each dose level based on the profile of DLE to establish the recommended phase 2 dose (RP2D) of rfhSP-D.

ETHICS AND DISSEMINATION

The RESPONSE study has received ethical approval from London-Brent NHS Research Health Authority ethics committee. Results from the study will be published in peer-reviewed journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBERS

ISRCTN17083028, NCT05898633.

PROTOCOL VERSION

RESPONSE Protocol V.4.0 24th July 2024.

Histological chorioamnionitis and pathological stages on very preterm infant outcomes

AIMS

Histological chorioamnionitis (HCA) is a condition linked to preterm birth and neonatal infection and its relationship with various pathological stages in extremely preterm neonates, and with their associated short- and long-term consequences, remains a subject of research. This study investigated the connection between different pathological stages of HCA and both short-term complications and long-term outcomes in preterm infants born at or before 32 weeks of gestational age.

METHODS

Preterm infants born at ≤ 32 weeks of gestation who underwent placental pathology evaluation and were followed-up at 18-24 months of corrected age were included. Neonates were classified based on their exposure to HCA and were further subdivided into different groups according to maternal inflammatory responses (MIR) and fetal inflammatory responses (FIR) stages. We compared short-term complications during their hospital stay between the HCA-exposed and -unexposed groups and examined the influence of HCA stages on long-term outcomes.

RESULTS

The HCA group exhibited distinct characteristics such as higher rates of premature rupture of membranes > 18 h, reduced amniotic fluid, early-onset sepsis, bronchopulmonary dysplasia and intraventricular haemorrhage (IVH) grades III-IV (P < 0.05). The moderate-severe HCA group displayed lower gestational age, lower birth weight and higher incidence of IVH (grades III-IV) and preterm sepsis compared with the mild HCA group (P < 0.05). After adjusting for confounders, the MIR stages 2-3 group showed associations with cognitive impairment and cerebral palsy (P < 0.05), and the FIR stages 2-3 group also showed poor long-term outcomes and cognitive impairment (P < 0.05).

CONCLUSIONS

Moderate-severe HCA was associated with increased early-onset sepsis, severe IVH and poor long-term outcomes, including cognitive impairment and cerebral palsy. Vigilant prevention strategies are warranted for severe HCA cases in order to mitigate poorer clinical outcomes.

Research Hotspots and Trends in the Diagnosis of Chorioamnionitis: Based on Bibliometric Analysis from 2010 to 2022

OBJECTIVE

This study aimed to conduct a bibliometric analysis of literature related to the diagnosis of chorioamnionitis (CAM) and to point out the current research progress, hotspots, and development trends of CAM research.

STUDY DESIGN

Literature on the diagnosis of CAM from the Web of Science Core Collection (WoSCC) between 2010 and 2022 was retrieved. CiteSpace, VOSviewer, and Online Analysis Platform (OALM) were used to draw maps of authors, articles, journals, institutions, countries/regions, and keywords.

RESULTS

A total of 312 articles were included, and the number of articles gradually increased over the study period. The author with the largest number of articles was Roberto Romero. The institution with the largest number of articles was Wayne State University School of Medicine, and the United States was the country that produced the largest number of articles. Analysis of keywords and outbreak words suggested that future research hotspots and trends may focus on early treatment of CAM and more precise, noninvasive, and more sensitive diagnoses.

CONCLUSION

In this study, visualization software and data information mining were innovatively used to conduct a bibliometric analysis of articles in the field of CAM diagnosis, and the current status, hotspots, and development of this field were obtained. Future research hotspots may be the precision diagnosis and treatment of CAM.

KEY POINTS

· There is no bibliometric study on CAM diagnosis in the existing literature.. · The prediction of CAM diagnosis is an important topic to improve maternal and infant prognosis.. · Bibliometrics can effectively guide the direction of future research..

Histologic chorioamnionitis in extremely preterm births, microbiological findings and infant outcome

BACKGROUND

Histologic chorioamnionitis (HCA) is most often caused by ascending bacterial infection originating from the cervicovaginal tract.

OBJECTIVES

To investigate whether HCA with a fetal inflammatory response (FIR) has a worse clinical outcome than HCA alone. Further, if FIR or a positive maternal microbiologic culture obtained prior to birth were related to adverse neonatal outcomes in a cohort of extremely preterm (EP) neonates.

METHODS

Prospective observational cohort study recruiting EP singleton pregnancies (gestational age at birth ≤28 weeks) with confirmed HCA. FIR was defined by fetal neutrophils in the chorionic vessels and/or umbilical vessels. Positive culture was defined as growth of potentially pathogenic bacteria in a sample from the cervicovaginal tract prior to birth, or if a cervicovaginal culture was lacking, a culture result from the placenta was used. Logistic regression was used to estimate odds ratios and 95% confidence intervals for the associations between FIR, a positive culture result and adverse outcomes, defined as bronchopulmonary dysplasia (BPD), brain pathology assessed by magnetic resonance imaging, retinopathy of prematurity, necrotizing enterocolitis, early-onset neonatal sepsis, and perinatal death. A composite outcome variable included one or more adverse outcomes.

RESULTS

We included 71 cases with HCA, of which 51 (72%) had FIR. Maternal age, rate of clinical chorioamnionitis (CCA), preterm pre-labor rupture of membranes (PPROM), the number of women receiving antenatal steroids and antibiotics, and the rate of positive maternal cultures of potentially pathogenic bacteria were all significantly higher in the HCA with FIR. Neonates in the FIR group had significantly higher levels of blood leukocytes compared to those without. FIR was associated with a longer interval from PPROM to delivery (log-rank test: p = .022). Microbiological sampling had been performed in 63 (89%) cases, of which 60 (95%) were cervicovaginal samples. No associations were found between a positive culture and adverse neonatal outcomes, in contrast to FIR, that was significantly associated to BPD and brain pathology.

CONCLUSIONS

In a cohort of EP pregnancies with confirmed HCA, the presence of FIR was associated with advanced maternal age, CCA, PPROM, antenatal steroids and antibiotics, and a positive maternal culture of potentially pathogenic bacteria. However, the presence of FIR, and not a positive culture, was associated with adverse neonatal outcomes.

The Role of the Interleukin-1 Family in Complications of Prematurity

Preterm birth is a major contributor to neonatal morbidity and mortality. Complications of prematurity such as bronchopulmonary dysplasia (BPD, affecting the lung), pulmonary hypertension associated with BPD (BPD-PH, heart), white matter injury (WMI, brain), retinopathy of prematurity (ROP, eyes), necrotizing enterocolitis (NEC, gut) and sepsis are among the major causes of long-term morbidity in infants born prematurely. Though the origins are multifactorial, inflammation and in particular the imbalance of pro- and anti-inflammatory mediators is now recognized as a key driver of the pathophysiology underlying these illnesses. Here, we review the involvement of the interleukin (IL)-1 family in perinatal inflammation and its clinical implications, with a focus on the potential of these cytokines as therapeutic targets for the development of safe and effective treatments for early life inflammatory diseases.

Cord blood immune profile: Associations with higher prenatal plastic chemical levels

Prenatal exposure to plastic chemicals has been associated with alterations to early-life immune function in children. However, previous studies have generally been small and focused on limited repertoires of immune indices. In a large population-based pre-birth cohort (n = 1074), third-trimester measurements of eight phthalate metabolites and three analogues of bisphenols were used to estimate prenatal exposure to phthalate and bisphenol compounds. In cord blood, immune cell populations were measured by flow cytometry and an extensive panel of cytokines and chemokines were measured by multiplex immunoassay. We used these cord blood analytes to estimate "early life" immune profiles. The full study sample comprises data from 774 infants with prenatal plastic metabolite measurements and any cord blood immune data. Multiple linear regression analysis was used to evaluate whether prenatal phthalate and bisphenol exposure was prospectively associated with cord blood immune cell populations and cytokine and chemokine levels. Generally, inverse associations were observed between prenatal phthalate exposure and cord blood immune indices. Higher exposure to di-n-butyl phthalate was associated with lower cord blood levels of platelet-derived growth factor (PDGF) and interferon gamma-induced protein 10 (IP-10); higher exposure to the sum of dibutyl phthalates was associated with lower cord blood levels of IP-10; and higher exposure to benzyl butyl phthalate was associated with lower cord blood levels of interleukin 1 beta (IL-1β). There was less evidence of associations between bisphenols and cord blood immune indices. These results extend previous work examining prenatal plastic chemical exposure and early-life immune development and highlight the importance of further examination of potential associations with health-related outcomes.

Preterm ETs Are Significantly Reduced Compared with Adults and Partially Reduced Compared with Term Infants

The release of DNA by cells during extracellular trap (ET) formation is a defense function of neutrophils and monocytes. Neutrophil ET (NET) formation in term infants is reduced compared to adults. Objective: The aim was to quantify NET and monocyte ET (MET) release and the respective key enzymes myeloperoxidase (MPO) and neutrophil elastase (NE) in preterm infants. In this prospective explorative study, ET induction was stimulated by N-formylmethionine-leucyl-phenylalanine (fMLP), phorbol 12-myristate 13-acetate (PMA), lipopolysaccharide (LPS), and lipoteichoic acid (LTA) in the cord blood of preterm infants (n = 55, 23-36 weeks) compared to term infants and adults. METs were quantified by microscopy, and NETs by microscopy and flow cytometry. We also determined the MPO levels within NETs and the intracellular concentrations of NE and MPO in neutrophils. The percentage of neutrophils releasing ET was significantly reduced for preterm infants compared to adults for all stimulants, and with a 68% further reduction for PMA compared to term infants (p = 0.0141). The NET area was not reduced except for when fMLP was administered. The amount of MPO in NET-producing cells was reduced in preterm infants compared to term infants. For preterm infants, but not term infants, the percentage of monocytes releasing ETs was significantly reduced compared to healthy adults for LTA and LPS stimulation. Conclusion: In preterm infants, ETs are measurable parts of the innate immune system, but are released in a reduced percentage of cells compared to adults.