The fetal inflammatory response syndrome

The alarmin interleukin-1α causes preterm birth through the NLRP3 inflammasome

Sterile intra-amniotic inflammation is a clinical condition frequently observed in women with preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Growing evidence suggests that alarmins found in amniotic fluid, such as interleukin (IL)-1α, are central initiators of sterile intra-amniotic inflammation. However, the causal link between elevated intra-amniotic concentrations of IL-1α and preterm birth has yet to be established. Herein, using an animal model of ultrasound-guided intra-amniotic injection of IL-1α, we show that elevated concentrations of IL-1α cause preterm birth and neonatal mortality. Additionally, using immunoblotting techniques and a specific immunoassay, we report that the intra-amniotic administration of IL-1α induces activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in the fetal membranes, but not in the decidua, as evidenced by a concomitant increase in the protein levels of NLRP3, active caspase-1, and IL-1β. Lastly, using Nlrp3-/- mice, we demonstrate that the deficiency of this inflammasome sensor molecule reduces the rates of preterm birth and neonatal mortality caused by the intra-amniotic injection of IL-1α. Collectively, these results demonstrate a causal link between elevated IL-1α concentrations in the amniotic cavity and preterm birth as well as adverse neonatal outcomes, a pathological process that is mediated by the NLRP3 inflammasome. These findings shed light on the mechanisms underlying sterile intra-amniotic inflammation and provide further evidence that this clinical condition can potentially be treated by targeting the NLRP3 inflammasome.

Role of Infection and Immunity in Bovine Perinatal Mortality: Part 2. Fetomaternal Response to Infection and Novel Diagnostic Perspectives

Simple Summary

Bovine perinatal mortality (death of the fetus or calf before, during, or within 48 h of calving at full term (≥260 days) may be caused by noninfectious and infectious causes. Although infectious causes of fetal mortality are diagnosed less frequently, infection in utero may also compromise the development of the fetus without causing death. This review presents fetomaternal responses to infection and the changes which can be observed in such cases. Response to infection, especially the concentration of immunoglobulins and some acute-phase proteins, may be used for diagnostic purposes. Some changes in internal organs may also be used as an indicator of infection in utero. However, in all cases (except pathogen-specific antibody response) non-pathogen-specific responses do not aid in pathogen-specific diagnosis of the cause of calf death. But, nonspecific markers of in utero infection may allow us to assign the cause of fetal mortality to infection and thus increase our overall diagnosis rate, particularly in cases of the “unexplained stillbirth”.

Abstract

Bovine perinatal mortality due to infection may result either from the direct effects of intrauterine infection and/or the fetal response to such infection, leading to the fetal inflammatory response syndrome (FIRS). Both intrauterine infection and FIRS, which causes multi-organ damage and involution of immune organs, compromise fetal survivability, sometimes fatally. Organ injury associated with FIRS may, in addition to causing fetal mortality, irreversibly compromise extrauterine adaptation of the neonate, a recognized problem in human fetuses. Diagnosis of intrauterine infection and of FIRS requires related, but independent analytical approaches. In addition to detection of pathogens, the immune and inflammatory responses of the bovine fetus may be utilized to diagnose intrauterine infection. This can be done by detection of specific changes in internal organs and the measurement of antibodies and/or elements of the acute phase reaction. Currently our ability to diagnose FIRS in bovine fetuses and neonates is limited to research studies. This review focuses on both the fetomaternal response to infection and diagnostic methods which rely on the response of the fetus to infection and inflammatory changes, as well other methods which may improve diagnosis of intrauterine infection in cases of bovine perinatal mortality.

Immunological and physiopathological approach of COVID-19 in pregnancy

Coronavirus disease-2019 (COVID-19) related to Coronavirus-2 (SARS-CoV-2) is a worldwide health concern. Despite the majority of patients will evolve asymptomatic or mild-moderate upper respiratory tract infections, 20% will develop severe disease. Based on current pathogenetic knowledge, a severe COVID-19 form is mainly a hyperinflammatory, immune-mediated disorder, triggered by a viral infection. Due to their particular immunological features, pregnant women are supposed to be particularly susceptible to complicate by intracellular infections as well as immunological disturbances. As an example, immune-thrombosis has been identified as a common immune-mediated and pathogenic phenomenon both in COVID-19, in obstetric diseases and in COVID-19 pregnant women. According to extensive published clinical data, is rationale to expect an interference with the normal development of pregnancy in selected SARS-CoV-2-infected cases, mainly during third trimester.This manuscript provides insights of research to elucidate the potential harmful responses to SARS-CoV-2 and /or other coronavirus infections, as well as bidirectional interactions between COVID-19 and pregnancy to improve their respective management.

Amniotic fluid interleukin 6 and interleukin 8 are superior predictors of fetal lung injury compared with maternal or fetal plasma cytokines or placental histopathology in a nonhuman primate model

BACKGROUND

Intra-amniotic infection or inflammation is common in early preterm birth and associated with substantial neonatal lung morbidity owing to fetal exposure to proinflammatory cytokines and infectious organisms. Amniotic fluid interleukin 8, a proinflammatory cytokine, was previously correlated with the development of neonatal bronchopulmonary dysplasia, but whether amniotic fluid cytokines or placental pathology more accurately predicts neonatal lung pathology and morbidity is unknown. We have used a pregnant nonhuman primate model of group B Streptococcus infection to study the pathogenesis of intra-amniotic infection, bacterial invasion of the amniotic cavity and fetus, and microbial-host interactions. In this nonhuman primate model, we have studied the pathogenesis of group B Streptococcus strains with differing potential for virulence, which has resulted in a spectrum of intra-amniotic infection and fetal lung injury that affords the opportunity to study the inflammatory predictors of fetal lung pathology and injury.

OBJECTIVE

This study aimed to determine whether fetal lung injury is best predicted by placental histopathology or the cytokine response in amniotic fluid or maternal plasma.

STUDY DESIGN

Chronically catheterized pregnant monkeys (Macaca nemestrina, pigtail macaque) at 116 to 125 days gestation (term at 172 days) received a choriodecidual inoculation of saline (n=5), weakly hemolytic group B Streptococcus strain (n=5, low virulence), or hyperhemolytic group B Streptococcus strain (n=5, high virulence). Adverse pregnancy outcomes were defined as either preterm labor, microbial invasion of the amniotic cavity, or development of the fetal inflammatory response syndrome. Amniotic fluid and maternal and fetal plasma samples were collected after inoculation, and proinflammatory cytokines (tumor necrosis factor alpha, interleukin beta, interleukin 6, interleukin 8) were measured by a multiplex assay. Cesarean delivery was performed at the time of preterm labor or within 1 week of inoculation. Fetal necropsy was performed at the time of delivery. Placental pathology was scored in a blinded fashion by a pediatric pathologist, and fetal lung injury was determined by a semiquantitative score from histopathology evaluating inflammatory infiltrate, necrosis, tissue thickening, or collapse scored by a veterinary pathologist.

RESULTS

The principal findings in our study are as follows: (1) adverse pregnancy outcomes occurred more frequently in animals receiving hyperhemolytic group B Streptococcus (80% with preterm labor, 80% with fetal inflammatory response syndrome) than in animals receiving weakly hemolytic group B Streptococcus (40% with preterm labor, 20% with fetal inflammatory response syndrome) and in controls (0% preterm labor, 0% fetal inflammatory response syndrome); (2) despite differences in the rate of adverse pregnancy outcomes and fetal inflammatory response syndrome, fetal lung injury scores were similar between animals receiving the weakly hemolytic group B Streptococcus strains and animals receiving the hyperhemolytic group B Streptococcus strains; (3) fetal lung injury score was significantly correlated with peak amniotic fluid cytokines interleukin 6 and interleukin 8 but not tumor necrosis factor alpha or interleukin 1 beta; and (4) fetal lung scores were poorly correlated with maternal and fetal plasma cytokine levels and placental pathology.

CONCLUSION

Amniotic fluid interleukin 6 and interleukin 8 levels were superior predictors of fetal lung injury than placental histopathology or maternal plasma cytokines. This evidence supports a role for amniocentesis in the prediction of neonatal lung morbidity owing to intra-amniotic infection, which cannot be provided by cytokine analysis of maternal plasma or placental histopathology.

Effects of SARS-COV-2 infection on fetal pulmonary artery Doppler parameters

Purpose

To determine the effect of SARS‐CoV‐2 infection on the fetal pulmonary system using the acceleration time (AT), ejection time (ET), and acceleration/ejection time ratio (PATET) of the fetal main pulmonary artery Doppler waveform.

Methods

We prospectively studied pregnant women attending our hospital with confirmed SARS‐CoV‐2 infection by RT‐PCR test and an age‐matched control group who admitted for routine prenatal care. An ultrasound examination that included measurements of the AT, ET, and AT/ET ratio (PATET) were performed and the results were compared.

Results

Fifty‐five SARS‐CoV‐2‐infected and 93 control group pregnant women were included in this study. AT found higher in the COVID‐19 positive group when compared with controls. When the ET and PATET parameters were compared, no differences were detected between the groups. Eleven neonates had Neonatal Intensive Care Unit (NICU) requirement in the COVID‐19 positive group while there were none in the control group. All fetal pulmonary artery Doppler values were decreased in NICU admitted fetuses. The mean gestational week of this group was lower than non‐NICU COVID‐19 positive group and the control group.

Conclusion

COVID‐19 infection increases fetal pulmonary blood flow, which appears high AT values on Doppler parameters. NICU admission only occurred in the COVID‐19 group and their Doppler values were found significantly lower than non‐NICU COVID‐19 group. The clinical significance of this result must be evaluated with further studies.

Recording and manipulation of vagus nerve electrical activity in chronically instrumented unanesthetized near term fetal sheep

BACKGROUND

The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli. This is due to the unique amenability of the unanesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection, recording of bioelectrical activity, application of electric stimulation, and in vivo organ imaging. Recently, there has been growing interest in the pleiotropic effects of vagus nerve stimulation (VNS) on various organ systems such as innate immunity and inflammation, and metabolism. There is no approach to study this in utero and corresponding physiological understanding is scarce.

NEW METHOD

Based on our previous presentation of a stable chronically instrumented unanesthetized fetal sheep model, here we describe the surgical instrumentation procedure allowing successful implantation of a cervical uni- or bilateral VNS probe with or without vagotomy.

RESULTS

In a cohort of 68 animals, we present the changes in blood gas, metabolic, and inflammatory markers during the postoperative period. We detail the design of a VNS probe which also allows recording from the fetal nerve. We also present an example of fetal vagus electroneurogram (VENG) recorded from the VNS probe and an analytical approach to the data.

COMPARISON WITH EXISTING METHODS

This method represents the first implementation of fetal VENG/VNS in a large pregnant mammalian organism.

CONCLUSIONS

This study describes a new surgical procedure allowing to record and manipulate chronically fetal vagus nerve activity in an animal model of human pregnancy.

Amniotic fluid neutrophil gelatinase-associated lipocalin and L-type fatty acid-binding protein in predicting fetal inflammatory response syndrome

AIM

To analyze the effectiveness of amniotic fluid neutrophil gelatinase-associated lipocalin and L-type fatty acid-binding protein as predictive factors for fetal inflammatory response syndrome.

METHODS

We classified single pregnancy cases into the fetal inflammatory response syndrome and nonfetal inflammatory response syndrome groups. We collected amniotic fluid at vaginal delivery and cesarean section and compared the patient characteristics, maternal white blood cell count, C-reactive protein level, and amniotic fluid interleukin-6; neutrophil gelatinase-associated lipocalin; and L-type fatty acid-binding protein levels between the groups. We further analyzed the relationship between L-type fatty acid-binding protein levels and neonatal clinical outcomes.

RESULTS

We analyzed 129 pregnancies, of which 36 and 93 (27.9% and 72.1%, respectively) were classified into the fetal inflammatory response syndrome and nonfetal inflammatory response syndrome groups, respectively. We observed significant differences in the maternal white blood cell counts and amniotic fluid interleukin-6 and neutrophil gelatinase-associated lipocalin levels. On the multivariate analysis, the useful predictive factors were maternal white blood cell count and amniotic fluid interleukin-6 and neutrophil gelatinase-associated lipocalin levels. Furthermore, the level of L-type fatty acid-binding protein was significantly higher in the transient tachypnea of the newborn and postnatal respiratory support group than in the control group.

CONCLUSIONS

The maternal white blood cell count and amniotic interleukin-6 and neutrophil gelatinase-associated lipocalin levels were effective predictors of fetal inflammatory response syndrome. Amniotic fluid L-type fatty acid-binding protein level was an effective predictor of neonatal respiratory support.

Severe Acute Respiratory Syndrome Coronavirus 2 Placental Infection and Inflammation Leading to Fetal Distress and Neonatal Multi-Organ Failure in an Asymptomatic Woman

BACKGROUND

In general, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy is not considered to be an increased risk for severe maternal outcomes but has been associated with an increased risk for fetal distress. Maternal-fetal transmission of SARS-CoV-2 was initially deemed uncertain; however, recently a few cases of vertical transmission have been reported. The intrauterine mechanisms, besides direct vertical transmission, leading to the perinatal adverse outcomes are not well understood.

METHODS

Multiple maternal, placental, and neonatal swabs were collected for the detection of SARS-CoV-2 using real-time quantitative polymerase chain reaction (RT-qPCR). Serology of immunoglobulins against SARS-CoV-2 was tested in maternal, umbilical cord, and neonatal blood. Placental examination included immunohistochemical investigation against SARS-CoV-2 antigen expression, with SARS-CoV-2 ribonucleic acid (RNA) in situ hybridization and transmission electron microscopy.

RESULTS

RT-qPCRs of the oropharynx, maternal blood, vagina, placenta, and urine were all positive over a period of 6 days, while breast milk, feces, and all neonatal samples tested negative. Placental findings showed the presence of SARS-CoV-2 particles with generalized inflammation characterized by histiocytic intervillositis with diffuse perivillous fibrin depositions with damage to the syncytiotrophoblasts.

CONCLUSIONS

Placental infection by SARS-CoV-2 leads to fibrin depositions hampering fetal-maternal gas exchange with resulting fetal distress necessitating a premature emergency cesarean section. Postpartum, the neonate showed a fetal or pediatric inflammatory multisystem-like syndrome with coronary artery ectasia temporarily associated with SARS-CoV-2 for which admittance and care on the neonatal intensive care unit (NICU) were required, despite being negative for SARS-CoV-2. This highlights the need for awareness of adverse fetal and neonatal outcomes during the current coronavirus disease 2019 pandemic, especially considering that the majority of pregnant women appear asymptomatic.

ZIKV Disrupts Placental Ultrastructure and Drug Transporter Expression in Mice

Congenital Zika virus (ZIKV) infection can induce fetal brain abnormalities. Here, we investigated whether maternal ZIKV infection affects placental physiology and metabolic transport potential and impacts the fetal outcome, regardless of viral presence in the fetus at term. Low (103 PFU-ZIKVPE243; low ZIKV) and high (5x107 PFU-ZIKVPE243; high ZIKV) virus titers were injected into immunocompetent (ICompetent C57BL/6) and immunocompromised (ICompromised A129) mice at gestational day (GD) 12.5 for tissue collection at GD18.5 (term). High ZIKV elicited fetal death rates of 66% and 100%, whereas low ZIKV induced fetal death rates of 0% and 60% in C57BL/6 and A129 dams, respectively. All surviving fetuses exhibited intrauterine growth restriction (IUGR) and decreased placental efficiency. High-ZIKV infection in C57BL/6 and A129 mice resulted in virus detection in maternal spleens and placenta, but only A129 fetuses presented virus RNA in the brain. Nevertheless, pregnancies in both strains produced fetuses with decreased head sizes (p<0.05). Low-ZIKV-A129 dams had higher IL-6 and CXCL1 levels (p<0.05), and their placentas showed increased CCL-2 and CXCL-1 contents (p<0.05). In contrast, low-ZIKV-C57BL/6 dams had an elevated CCL2 serum level and increased type I and II IFN expression in the placenta. Notably, less abundant microvilli and mitochondrial degeneration were evidenced in the placental labyrinth zone (Lz) of ICompromised and high-ZIKV-ICompetent mice but not in low-ZIKV-C57BL/6 mice. In addition, decreased placental expression of the drug transporters P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) and the lipid transporter Abca1 was detected in all ZIKV-infected groups, but Bcrp and Abca1 were only reduced in ICompromised and high-ZIKV ICompetent mice. Our data indicate that gestational ZIKV infection triggers specific proinflammatory responses and affects placental turnover and transporter expression in a manner dependent on virus concentration and maternal immune status. Placental damage may impair proper fetal-maternal exchange function and fetal growth/survival, likely contributing to congenital Zika syndrome.

Extracellular vesicle mediated feto-maternal HMGB1 signaling induces preterm birth

Preterm birth (PTB; <37 weeks of gestation) impacts ∼11% of all pregnancies and contributes to 1 million neonatal deaths worldwide annually. An understanding of the feto-maternal (F-M) signals that initiate birthing (parturition) at term is critical to design strategies to prevent their premature activation, resulting in PTB. Although endocrine and immune cell signaling are well-reported, fetal-derived paracrine signals capable of transitioning quiescent uterus to an active state of labor are poorly studied. Recent reports have suggested that senescence of the fetal amnion membrane coinciding with fetal growth and maturation generates inflammatory signals capable of triggering parturition. This is by increasing the inflammatory load at the feto-maternal interface (FMi) tissues (i.e., amniochorion-decidua). High mobility group box 1 protein (HMGB1), an alarmin, is one of the inflammatory signals released by senescent amnion cells via extracellular vesicles (exosomes; 40-160 nm). Increased levels of HMGB1 in the amniotic fluid, cord and maternal blood are associated with term and PTB. This study tested the hypothesis that senescent amnion cells release HMGB1, which is fetal signaling capable of increasing FMi inflammation, predisposing them to parturition. To test this hypothesis, exosomes from amnion epithelial cells (AECs) grown under normal conditions were engineered to contain HMGB1 by electroporation (eHMGB1). eHMGB1 was characterized (quantity, size, shape, markers and loading efficiency), and its propagation through FMi was tested using a four-chamber microfluidic organ-on-a-chip device (FMi-OOC) that contained four distinct cell types (amnion and chorion mesenchymal, chorion trophoblast and decidual cells) connected through microchannels. eHMGB1 propagated through the fetal cells and matrix to the maternal decidua and increased inflammation (receptor expression [RAGE and TLR4] and cytokines). Furthermore, intra-amniotic injection of eHMGB1 (containing 10 ng) into pregnant CD-1 mice on embryonic day 17 led to PTB. Injecting carboxyfluorescein succinimidyl ester (CFSE)-labeled eHMGB1, we determined in vivo kinetics and report that eHMGB1 trafficking resulting in PTB was associated with increased FMi inflammation. This study determined that fetal exosome mediated paracrine signaling can generate inflammation and induce parturition. Besides, in vivo functional validation of FMi-OOC experiments strengthens the reliability of such devices to test physiologic and pathologic systems.

Fetal Growth Restriction and Subsequent Low Grade Fetal Inflammatory Response Are Associated with Early-Onset Neonatal Sepsis in the Context of Early Preterm Sterile Intrauterine Environment

There is no information about whether fetal growth restriction (FGR) is an independent risk factor for low-grade fetal inflammatory response (FIR), and which is more valuable for the prediction of early-onset neonatal sepsis (EONS) between low-grade FIR or fetal inflammatory response syndrome (FIRS) in the context of human early preterm sterile intrauterine environment. We examined FIR (umbilical cord plasma (UCP) CRP concentration at birth) according to the presence or absence of FGR (birth weight < 5th percentile for gestational age (GA)) and EONS in 81 singleton preterm births (GA at delivery: 24.5~33.5 weeks) within 72 h after amniocentesis and with sterile intrauterine environment. A sterile intrauterine environment was defined by the presence of both a sterile amniotic fluid (AF) (AF with both negative culture and MMP-8 < 23 ng/mL) and inflammation-free placenta. Median UCP CRP (ng/mL) was higher in cases with FGR than in those without FGR (63.2 vs. 34.5; p = 0.018), and FGR was an independent risk factor for low-grade FIR (UCP CRP ≥ 52.8 ng/mL) (OR 3.003, 95% CI 1.024-8.812, p = 0.045) after correction for confounders. Notably, low-grade FIR (positive likelihood-ratio (LR) and 95% CI, 2.3969 (1.4141-4.0625); negative-LR and 95% CI, 0.4802 (0.2591-0.8902)), but not FIRS (positive-LR and 95% CI, 2.1071 (0.7526-5.8993); negative-LR and 95% CI, 0.8510 (0.6497-1.1145)), was useful for the identification of EONS. In conclusion, FGR is an independent risk factor for low-grade FIR, and low-grade FIR, but not FIRS, has a value for the identification of EONS in the context of the early preterm sterile intrauterine environment.

Fetal Cardiovascular Decompensation During Labor Predicted From the Individual Heart Rate Tracing: A Machine Learning Approach in Near-Term Fetal Sheep Model

Background: When exposed to repetitive umbilical cord occlusions (UCO) with worsening acidemia, fetuses eventually develop cardiovascular decompensation manifesting as pathological hypotensive arterial blood pressure (ABP) responses to fetal heart rate (FHR) decelerations. Failure to maintain cardiac output during labor is a key event leading up to brain injury. We reported that the timing of the event when a fetus begins to exhibit this cardiovascular phenotype is highly individual and was impossible to predict. Objective: We hypothesized that this phenotype would be reflected in the individual behavior of heart rate variability (HRV) as measured by root mean square of successive differences of R-R intervals (RMSSD), a measure of vagal modulation of HRV, which is known to increase with worsening acidemia. This is clinically relevant because HRV can be computed in real-time intrapartum. Consequently, we aimed to predict the individual timing of the event when a hypotensive ABP pattern would emerge in a fetus from a series of continuous RMSSD data. Study Design: Fourteen near-term fetal sheep were chronically instrumented with vascular catheters to record fetal arterial blood pressure, umbilical cord occluder to mimic uterine contractions occurring during human labor and ECG electrodes to compute the ECG-derived HRV measure RMSSD. All animals were studied over a ~6 h period. After a 1-2 h baseline control period, the animals underwent mild, moderate, and severe series of repetitive UCO. We applied the recently developed machine learning algorithm to detect physiologically meaningful changes in RMSSD dynamics with worsening acidemia and hypotensive responses to FHR decelerations. To mimic clinical scenarios using an ultrasound-based 4 Hz FHR sampling rate, we recomputed RMSSD from FHR sampled at 4 Hz and compared the performance of our algorithm under both conditions (1,000 Hz vs. 4 Hz). Results: The RMSSD values were highly non-stationary, with four different regimes and three regime changes, corresponding to a baseline period followed by mild, moderate, and severe UCO series. Each time series was characterized by seemingly randomly occurring (in terms of timing of the individual onset) increase in RMSSD values at different time points during the moderate UCO series and at the start of the severe UCO series. This event manifested as an increasing trend in RMSSD values, which counter-intuitively emerged as a period of relative stationarity for the time series. Our algorithm identified these change points as the individual time points of cardiovascular decompensation with 92% sensitivity, 86% accuracy and 92% precision which corresponded to 14 ± 21 min before the visual identification. In the 4 Hz RMSSD time series, the algorithm detected the event with 3 times earlier detection times than at 1,000 Hz, i.e., producing false positive alarms with 50% sensitivity, 21% accuracy, and 27% precision. We identified the overestimation of baseline FHR variability by RMSSD at a 4 Hz sampling rate to be the cause of this phenomenon. Conclusions: The key finding is demonstration of FHR monitoring to detect fetal cardiovascular decompensation during labor. This validates the hypothesis that our HRV-based algorithm identifies individual time points of ABP responses to UCO with worsening acidemia by extracting change point information from the physiologically related fluctuations in the RMSSD signal. This performance depends on the acquisition accuracy of beat to beat fluctuations achieved in trans-abdominal ECG devices and fails at the sampling rate used clinically in ultrasound-based systems. This has implications for implementing such an approach in clinical practice.

Sneathia: an emerging pathogen in female reproductive disease and adverse perinatal outcomes

Sneathia is an emerging pathogen implicated in adverse reproductive and perinatal outcomes. Although scarce, recent data suggest that vaginally residing Sneathia becomes pathogenic following its ascension into the upper urogenital tract, amniotic fluid, placenta, and foetal membranes. The role of Sneathia in women's health and disease is generally underappreciated because the cultivation of these bacteria is limited by their complex nutritional requirements, slow growth patterns, and anaerobic nature. For this reason, molecular methods are typically required for the detection and differential diagnosis of Sneathia infections. Here, we review the laboratory methods used for the diagnosis of Sneathia infections, the molecular mechanisms underlying its virulence, and its sensitivity to antibiotics. We further review the evidence of Sneathia's contributions to the pathogenesis of bacterial vaginosis, chorioamnionitis, preterm prelabour rupture of membranes, spontaneous preterm labour, stillbirth, maternal and neonatal sepsis, HIV infection, and cervical cancer. Collectively, growing evidence indicates that Sneathia represents an important yet underappreciated pathogen affecting the development and progression of several adverse clinical conditions diagnosed in pregnant women and their neonates, as well as in non-pregnant women.

Fetal Inflammatory Response Syndrome Associated With Maternal SARS-CoV-2 Infection

Amid the coronavirus disease 2019 pandemic, uncertainty exists about the potential for vertical transmission from mothers infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the fetus in utero. In this case report, we aim to demonstrate the occurrence of a fetal inflammatory response syndrome associated with maternal SARS-CoV-2 infection resulting in neonatal morbidity. In this report we describe an infant of a SARS-CoV-2-positive mother born prematurely with late-onset fever, thrombocytopenia, and elevated levels of inflammatory markers, all of which are consistent with a systemic inflammatory response. The neonate was tested for SARS-CoV-2 by using 2 nasopharyngeal swabs 24 hours apart, and results of both were negative. The result of a full workup for additional infectious pathogens was also negative. Although initially in critical condition in the perinatal period, the infant recovered completely before discharge. We hypothesize that this systemic inflammation occurred in response to maternal viral infection in the absence of vertical transmission of the virus. During the coronavirus disease 2019 pandemic, it will be important to consider the virus as a nidus for a fetal inflammatory response syndrome and resulting morbidity, even in the setting of a negative SARS-CoV-2 testing result in the infant.

Altered cytokine responses in children with cerebral palsy: pathogenesis and novel therapies

This commentary is on the original article by Zareen et al. on pages 407–412 of this issue.

Labor dystocia and risk of histological chorioamnionitis and funisitis: a study from a single tertiary referral center

Background

Intrauterine inflammation affects short- and long-term neonatal outcomes. Histological chorioamnionitis and funisitis are acute inflammatory responses in the fetal membranes and umbilical cord, respectively. Although labor dystocia includes a potential risk of intrauterine inflammation, the risk of histological chorioamnionitis and funisitis of labor dystocia has not been evaluated yet. This study aimed to examine the association between labor dystocia and risk of histological chorioamnionitis and funisitis.

Methods

In this retrospective cohort study, the cases who underwent histopathological examinations of the placenta and umbilical cord at Fukushima Medical University Hospital, Japan, between 2015 and 2020, were included. From the dataset, the pathological findings of the patients with labor dystocia and spontaneous preterm birth were reviewed. Based on the location of leukocytes, the inflammation in the placenta (histological chorioamnionitis) and umbilical cord (funisitis) was staged as 0–3. Multiple logistic regression analysis was performed to evaluate the risk of histological chorioamnionitis, histological chorioamnionitis stage ≥2, funisitis, and funisitis stage ≥2.

Result

Of 317 women who met the study criteria, 83 and 144 women had labor dystocia and spontaneous preterm birth, respectively, and 90 women were included as controls. Labor dystocia was a risk factor for histological chorioamnionitis (adjusted odds ratio, 6.3; 95% confidential interval, 1.9–20.5), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 6.0; 95% confidence interval, 1.7–21.8), funisitis (adjusted odds ratio, 15.4; 95% confidence interval, 2.3–101.3), and funisitis stage ≥2 (adjusted odds ratio, 18.5; 95% confidence interval, 2.5–134.0). Spontaneous preterm birth was also a risk factor for histological chorioamnionitis (adjusted odds ratio, 3.7; 95% confidence interval, 1.7–7.8), histological chorioamnionitis stage ≥2 (adjusted odds ratio, 3.0; 95% confidence interval, 1.2–7.9), and funisitis (adjusted odds ratio, 6.6; 95% confidence interval, 1.4–30.6). However, the adjusted odds ratio was smaller in spontaneous preterm births than in labor dystocia.

Conclusion

Labor dystocia is a risk factor for severe histological chorioamnionitis and funisitis. Further studies are required to evaluate the effects of histological chorioamnionitis and funisitis on long-term neonatal outcomes.

Fetal inflammation induces acute immune tolerance in the neonatal rat hippocampus

BACKGROUND

Infants born preterm due to chorioamnionitis are frequently affected by a fetal inflammatory response syndrome (FIRS) and then by subsequent postnatal infections. FIRS and postnatal systemic inflammatory events independently contribute to poor neurocognitive outcomes of preterm infants. Developmental integrity of the hippocampus is crucial for intact neurocognitive outcomes in preterms and hippocampally dependent behaviors are particularly vulnerable to preterm systemic inflammation. How FIRS modulates the hippocampal immune response to acute postnatal inflammatory events is not well understood.

METHODS

Prenatal LPS exposed (FIRS) and control neonatal rats received i.p. LPS or saline at postnatal day (P) 5. On P7, immune response was evaluated in the hippocampus of four treatment groups by measuring gene expression of inflammatory mediators and cytosolic and nuclear NFκB pathway proteins. Microglial activation was determined by CD11b+ and Iba1+ immunohistochemistry (IHC) and inflammatory gene expression of isolated microglia. Astrocyte reactivity was measured using Gfap+ IHC.

RESULTS

Postnatal LPS resulted in a robust hippocampal inflammatory response. In contrast, FIRS induced by prenatal LPS attenuated the response to postnatal LPS exposure, evidenced by decreased gene expression of inflammatory mediators, decreased nuclear NFκB p65 protein, and fewer activated CD11b+ and Iba1+ microglia. Isolated microglia demonstrated inflammatory gene upregulation to postnatal LPS without evidence of immune tolerance by prenatal LPS.

CONCLUSION

Prenatal LPS exposure induced immune tolerance to subsequent postnatal LPS exposure in the hippocampus. Microglia demonstrate a robust inflammatory response to postnatal LPS, but only a partial immune tolerance response.

No evidence for a placental microbiome in human pregnancies at term

BACKGROUND

The placenta plays an important role in the modulation of pregnancy immunity; however, there is no consensus regarding the existence of a placental microbiome in healthy full-term pregnancies.

OBJECTIVE

This study aimed to investigate the existence and origin of a placental microbiome.

STUDY DESIGN

A cross-sectional study comparing samples (3 layers of placental tissue, amniotic fluid, vernix caseosa, and saliva, vaginal, and rectal samples) from 2 groups of full-term births: 50 women not in labor with elective cesarean deliveries and 26 with vaginal deliveries. The comparisons were performed using polymerase chain reaction amplification and DNA sequencing techniques and bacterial culture experiments.

RESULTS

There were no significant differences regarding background characteristics between women who delivered by elective cesarean and those who delivered vaginally. Quantitative measurements of bacterial content in all 3 placental layers (quantitative polymerase chain reaction of the 16S ribosomal RNA gene) did not show any significant difference among any of the sample types and the negative controls. Here, 16S ribosomal RNA gene sequencing of the maternal side of the placenta could not differentiate between bacteria in the placental tissue and contamination of the laboratory reagents with bacterial DNA. Probe-specific quantitative polymerase chain reaction for bacterial taxa suspected to be present in the placenta could not detect any statistically significant difference between the 2 groups. In bacterial cultures, substantially more bacteria were observed in the placenta layers from vaginal deliveries than those from cesarean deliveries. In addition, 16S ribosomal RNA gene sequencing of bacterial colonies revealed that most of the bacteria that grew on the plates were genera typically found in human skin; moreover, it revealed that placentas delivered vaginally contained a high prevalence of common vaginal bacteria. Bacterial growth inhibition experiments indicated that placental tissue may facilitate the inhibition of bacterial growth.

CONCLUSION

We found no evidence to support the existence of a placental microbiome in our study of 76 term pregnancies, which used polymerase chain reaction amplification and sequencing techniques and bacterial culture experiments. Incidental findings of bacterial species could be due to contamination or to low-grade bacterial presence in some locations; such bacteria do not represent a placental microbiome per se.

Intestinal Goblet Cell Loss during Chorioamnionitis in Fetal Lambs: Mechanistic Insights and Postnatal Implications

Chorioamnionitis, an important cause of preterm birth, is linked to necrotizing enterocolitis (NEC). NEC is characterized by a disrupted mucus barrier, goblet cell loss, and endoplasmic reticulum (ER) stress of the intestinal epithelium. These findings prompted us to investigate the mechanisms underlying goblet cell alterations over time in an ovine chorioamnionitis model. Fetal lambs were intra-amniotically (IA) exposed to lipopolysaccharides (LPS) for 5, 12, or 24 h, or 2, 4, 8, or 15 d before premature delivery at 125 d gestational age (GA). Gut inflammation, the number, distribution, and differentiation of goblet cells, ER stress, and apoptosis were measured. We found a biphasic reduction in goblet cell numbers 24 h–2 d after, and 15 d after IA LPS exposure. The second decrease of goblet cell numbers was preceded by intestinal inflammation, apoptosis, and crypt ER stress, and increased SAM-pointed domain-containing ETS transcription factor (SPDEF)-positive cell counts. Our combined findings indicated that ER stress drives apoptosis of maturating goblet cells during chorioamnionitis, ultimately reducing goblet cell numbers. As similar changes have been described in patients suffering from NEC, these findings are considered to be clinically important for understanding the predecessors of NEC, and targeting ER stress in this context is interesting for future therapeutics.

MicroRNAs miR-4535 and miR-1915-5p in amniotic fluid as predictive biomarkers for chorioamnionitis

Background:

This study was performed to investigate the clinical significance of miR-4535 and miR-1915-5p in severe chorioamnionitis.

Materials & methods:

Amniotic fluid samples from 37 patients with severe chorioamnionitis were subjected to miRNA array analysis and ddPCR™. Diagnostic values were assessed using the receiver operating characteristic curve. The patients were separated into three groups according to Blanc’s criteria.

Results:

The expression of miR-4535 and miR-1915-5p was significantly correlated with the copy number of 16S rDNA, had extremely high diagnostic accuracy for severe chorioamnionitis, and was linked to maternal and fetal inflammation.

Conclusion:

miR-4535 and miR-1915-5p serve as promising biomarkers for the diagnosis of severe chorioamnionitis.

Chorioamnionitis and fetal inflammatory response syndrome, which is linked to chorioamnionitis, are considered serious diseases in perinatal care. In this study, miR-4535 and miR-1915-5p are recognized as promising biomarkers for the diagnosis of chorioamnionitis before delivery. In particular, the increased expression of miR-4535 in amniotic fluid is expected to be regarded as a positive indicator for fetal inflammatory response syndrome, and the elevated expression of miR-4535 in serum is also considered to predictively diagnose intrauterine infection in pregnancy. Our results highlight that further studies should explore the underlying clinical significance of miR-4535 and miR-1915-5p.

The determinant role of IL-6 in the establishment of inflammation leading to spontaneous preterm birth

Preterm birth (PTB) and its consequences are a major public health concern as preterm delivery is the main cause of mortality and morbidity at birth. There are many causes of PTB, but inflammation is undeniably associated with the process of premature childbirth and fetal injury. At present, treatments clinically available mostly involve attempt to arrest contractions (tocolytics) but do not directly address upstream maternal inflammation on development of the fetus. One of the possible solutions may lie in the modulation of inflammatory mediators. Of the many pro-inflammatory cytokines involved in the induction of PTB, IL-6 stands out for its pleiotropic effects and its involvement in both acute and chronic inflammation. Here, we provide a detailed review of the effects of IL-6 on the timing of childbirth, its occurrence during PTB and its indissociable roles with associated fetal tissue damage.

The Relationship Between Matrix Metalloproteinase-8 in After Birth Oral Fluid and Acute Histologic Chorioamnionitis in Preterm Delivery

Elevated concentration of matrix metalloproteinase-8 (MMP-8) in amniotic fluid is a known predictor of intra-amniotic inflammation and infection. The aim of this study was to determine the nature of the association between MMP-8 levels in oral fluid obtained immediately after birth and acute histologic chorioamnionitis (HCA) in preterm delivery. Oral fluid was collected from 93 consecutive preterm birth newborns between gestational weeks of 24 + 0 and 36 + 6. Concentrations of MMP-8 and interleukin-8 (IL-8) in after birth oral fluid were measured by ELISA. Acute HCA was defined as the presence of neutrophils infiltration into chorioamnionic membranes. Logistic regression analysis was used for the statistical analysis. MMP-8 concentrations in after birth oral fluid were significantly higher for women with acute HCA than for those without (median [range]; 68.3 ng/mL [0.06-12,479.6] vs. 10.2 ng/mL [0.06-1808.2], p = 0.002). A strong association was observed between MMP-8 and IL-8 levels (γ² = 0.87, p < 0.01). The cutoff level of MMP-8 in after birth oral fluid for acute HCA was 39.7 ng/mL (sensitivity of 63.2%, specificity of 81.1%). Multivariable logistic regression analysis showed MMP-8 in after birth oral fluid had an odds ratio of 4.17 for acute HCA (95% confidence interval [CI] = 1.08-16.17, p = 0.03). An elevated MMP-8 level in after birth oral fluid is associated with acute HCA in preterm birth. Newborn oral fluid immediately after birth might provide another source for information of intra-amniotic condition just before birth.

Maternal environmental enrichment modulates the immune response against an inflammatory challenge during gestation and protects the offspring

The production of pro-inflammatory cytokines during inflammatory processes has been associated with preterm birth (PTB) and fetal injury in humans and mice. We previously demonstrated that exposition to an enriched environment (EE), defined as a noninvasive and biological significant stimulus of the sensory pathway combined with voluntary physical activity, prevented PTB and perinatal death induced by the systemic administration of bacterial lipopolysaccharide (LPS) in mice. This work aimed to analyze whether EE modulates the immune response to the inflammatory process induced by LPS in peripheral blood and the amniotic fluid (AF). We observed that EE modulated maternal white blood cell count and its response to LPS. Furthermore, we found higher levels of IL-10 and a higher percentage of B cells in AF from EE exposed mothers compared to controls. Albeit LPS significantly increased IL-6 levels in AF from both groups, it was 3.6 times higher in control environment (CE) exposed group when compared to EE. Similarly, levels of IL-22 were significantly increased by LPS in both groups, but it was 6.7 times higher in EE group. Interestingly, levels of PGE2 in AF were only increased in the EE-LPS treated group, and a positive correlation between IL-22 and PGE2 levels was observed. During lactation, EE prevented LPS-induced delay in physical landmarks analyzed to assess offspring development. Our results suggest that EE modulates the immune response to systemic LPS-administration protecting the offspring. We propose that an EE-like protocol could be designed for pregnant women aiming at preventing the sequelae present in premature children.

Case Report: Neonatal Multi-System Inflammatory Syndrome Associated With SARS-CoV-2 Exposure in Two Cases From Saudi Arabia

Background: Vertical transmission of SARS-CoV-2 is under investigation. A few reports suggest the possibility of SARS-CoV-2 transmission from mothers to their neonates. Most neonates have mild symptoms, but some develop multisystem involvement and shock. Case Presentation: We report two cases of possible SARS-CoV-2 vertical transmission from mothers to their neonates. The first case shows maternal infection with SARS-CoV-2 in the second trimester followed by recurrent infection in the third trimester right before the delivery. The infant demonstrated respiratory distress soon after delivery along with myocardial dysfunction and multi-organ system involvement. The second case shows maternal infection with SARS-COV-2 at the time of delivery with preterm labor secondary to placental abruption, with that delivery resulting in the preterm neonate requiring non-invasive ventilation with multisystem involvement in the context of persistently positive SARS-COV-2 PCR in the neonate. Both neonates were treated with IVIG along with steroids. Both neonates recovered fully and were discharged and allowed to go home. Conclusion: In neonates, COVID-19 usually presents as an asymptomatic or mild illness; some may develop a more severe course. Our two cases, however, demonstrate that multisystem involvement, although rare, is possible. This report also supports the current evidence of possible vertical transmission from mothers to their neonates. This multisystem involvement might be underreported and should be considered in neonates with respiratory distress when born to mothers suffering of COVID-19. Clinical Trial Registration: [KSUMC], identifier [No#98763298].

Impact of chorioamnionitis on maternal and fetal levels of proinflammatory S100A12

Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS). The aim of this pilot study was to evaluate S100A12, a marker of innate immune activation, in mothers with or without HCA and in their infants. Concentrations of S100A12, interleukin 6 (IL-6), and C-reactive protein (CRP) were evaluated in maternal, cord, and neonatal blood of very preterm infants. Histologic examinations of the placenta and umbilical cords were performed. The 48 mother-neonate pairs enrolled were subdivided into two groups: HCA group (N = 15) and control group without HCA (N = 33). Maternal S100A12 levels were similar between HCA and control group. Similarly, S100A12 concentrations in cord and neonatal blood did not differ between the groups. However, high S100A12 concentrations were detected in cord and neonatal blood of two out of three neonates exposed to HCA associated with advanced funisitis. Concentrations of IL-6 and CRP were higher in maternal blood of the HCA group compared with controls (p < 0.05, p < 0.001; respectively), but no differences in cord or neonatal blood was found.Conclusion:S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA. It is currently unknown if S100A12 may identify neonates with FIRS. What is known: • Histologic chorioamnionitis (HCA) may lead to the fetal inflammatory response syndrome (FIRS). • S100A12 represents an early, sensitive, and specific diagnostic marker of inflammatory processes. What is new: • S100A12 did neither identify mothers with HCA nor very preterm infants exposed to HCA. • It is currently still unclear if S100A12 has a potential in identifying preterm infants with FIRS.

Antenatal pentoxifylline therapy to prevent endotoxin-induced fetal injury in the preterm goat model

Objective:

Pentoxifylline (PTX) has immunomodulatory properties and is known to reduce sepsis-associated infant mortality. We aimed to evaluate maternal oral and intra-amniotic administration of PTX for the prevention of fetal inflammation and injury in a caprine model.

Materials and Methods:

Inflammation-mediated fetal injury was induced with maternal granulocyte-colony stimulating factor and intra-amniotic endotoxin at 0.76 of gestation in date-mated pregnant goats. Eight groups were formed (n=4 each): Control, fetal injury, oral 30 mg/kg/day and 60 mg/kg/day PTX for 15 days + fetal injury, intra-amniotic 400 mg/kg and 800 mg/kg estimated fetal weight single-dose PTX with and without fetal injury. Preterm delivery by hysterotomy was performed at 0.80 of gestation to evaluate the fetal and placental effects. Immunochemistry for various markers including interleukins, caspases, cyclooxygenases, vimentin, myelin basic protein, and surfactant proteins were carried out in the fetal lungs, fetal brain, and placenta. Fetal plasma and amniotic fluid interleukins were also evaluated. Kruskal-Wallis H test and Mann-Whitney U test were used for comparisons.

Results:

High-dose (60 mg/kg/day) maternal prophylactic oral treatment attenuated endotoxin-related histological injury and was related to low inflammatory marker expressions comparable to the controls (p>0.05 except cyclooxygenase 2). Following maternal oral administration, fetal plasma and amniotic fluid levels of the studied interleukins were also lower than the untreated endotoxin-exposed animals (p<0.05 for all comparisons). Intra-amniotic PTX was associated with inconsistent results and increased inflammatory markers in some fetuses.

Conclusion:

Oral PTX before preterm birth mitigates intrauterine inflammation with neuroprotective effects in the fetus. PTX can be considered as a candidate drug for fetal brain injury prevention in the preterm period.

Intrauterine cytomegalovirus infection: a possible risk for cerebral palsy and related to its clinical features, neuroimaging findings: a retrospective study

Background

Abundant clinical evidences indicate that the increased risk of cerebral palsy (CP) may be associated with the intrauterine exposure to maternal infection. Cytomegalovirus (CMV) is a common cause of CP. However, little is known about the relationship between the intrauterine exposure of the fetus to CMV infection and CP. This study aims to explore the relationships between intrauterine CMV infection and clinical symptoms, classification, intelligence development and brain neuroimaging findings in children with CP.

Methods

In this study, 147 children with CP in recent 6 years were retrospectively analyzed (average age: 14.76 ± 3.07months; sex (M/F): 103/44). 148 children had CMV IgG and IgM positive sera identified by TORCH examination were selected as the control group (average age: 15.10 ± 3.21months; sex (M/F): 102/46), which also undergo the examination of CMV-DNA in urine. The age and sex of children in the control group were matched with those in the CP group. CMV-DNA in urine was detected by CMV fluorescence quantitative PCR, and t-test was performed to analyze the number of copies. For the CP group, standardized rehabilitation treatment was performed and the function of gross motor was evaluated by GMFM scale before and after treatment. The Gesell developmental scale (GDS) was used to assess the level of intellectual development. The classification of CP was conducted and the results of magnetic resonance imaging were analyzed. Finally, the correlations between the copy number of CMV-DNA and the clinical characteristics of children with CP were evaluated by the method of Pearson and Spearman correlation analysis.

Results

The level of CMV infection was negatively correlated with the developmental quotient (DQ) of children with CP. Negative association was found between the level of CMV infection and the level of the gross motor development. The level of CMV infection was positively related with the occurrence probability of spastic quadriplegia. However, no associations were found between the abnormalities of brain tissue and the number of CMV copies. Moreover, CMV infection might add the difficulty of the rehabilitation treatment.

Conclusions

CMV infection is a risk factor for the occurrence of CP in children. Pregnancy examination should be strengthened. Early detection and control of CMV infection may contribute to the rehabilitation of children with CP and reduce the disability and social burden.

RNA Sequencing Reveals Diverse Functions of Amniotic Fluid Neutrophils and Monocytes/Macrophages in Intra-Amniotic Infection

Intra-amniotic infection, the invasion of microbes into the amniotic cavity resulting in inflammation, is a clinical condition that can lead to adverse pregnancy outcomes for the mother and fetus as well as severe long-term neonatal morbidities. Despite much research focused on the consequences of intra-amniotic infection, there remains little knowledge about the innate immune cells that respond to invading microbes. We performed RNA-seq of sorted amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection to determine the transcriptomic differences between these innate immune cells. Further, we sought to identify specific transcriptomic pathways that were significantly altered by the maternal or fetal origin of amniotic fluid neutrophils and monocytes/macrophages, the presence of a severe fetal inflammatory response, and pregnancy outcome (i.e., preterm or term delivery). We show that significant transcriptomic differences exist between amniotic fluid neutrophils and monocytes/macrophages from women with intra-amniotic infection, indicating the distinct roles these cells play. The transcriptome of amniotic fluid immune cells varies based on their maternal or fetal origin, and the significant transcriptomic differences between fetal and maternal monocytes/macrophages imply that those of fetal origin exhibit impaired functions. Notably, transcriptomic changes in amniotic fluid monocytes/macrophages suggest that these immune cells collaborate with neutrophils in the trafficking of fetal leukocytes throughout the umbilical cord (i.e., funisitis). Finally, amniotic fluid neutrophils and monocytes/macrophages from preterm deliveries display enhanced transcriptional activity compared to those from term deliveries, highlighting the protective role of these cells during this vulnerable period. Collectively, these findings demonstrate the underlying complexity of local innate immune responses in women with intra-amniotic infection and provide new insights into the functions of neutrophils and monocytes/macrophages in the amniotic cavity.

Interleukin-8 dysregulation is implicated in brain dysmaturation following preterm birth

BACKGROUND

Preterm birth is associated with dysconnectivity of structural brain networks, impaired cognition and psychiatric disease. Systemic inflammation contributes to cerebral dysconnectivity, but the immune mediators driving this association are poorly understood. We analysed information from placenta, umbilical cord and neonatal blood, and brain MRI to determine which immune mediators link perinatal systemic inflammation with dysconnectivity of structural brain networks.

METHODS

Participants were 102 preterm infants (mean gestational age 29⁺¹ weeks, range 23⁺³-32⁺⁰). Placental histopathology identified reaction patterns indicative of histologic chorioamnionitis (HCA), and a customized immunoassay of 24 inflammation-associated proteins selected to reflect the neonatal innate and adaptive immune response was performed from umbilical cord (n = 55) and postnatal day 5 blood samples (n = 71). Brain MRI scans were acquired at term-equivalent age (41⁺⁰ weeks [range 38⁺⁰-44⁺⁴ weeks]) and alterations in white matter connectivity were inferred from mean diffusivity and neurite density index across the white matter skeleton.

RESULTS

HCA was associated with elevated concentrations of C5a, C9, CRP, IL-1β, IL-6, IL-8 and MCP-1 in cord blood, and IL-8 concentration predicted HCA with an area under the receiver operator curve of 0.917 (95% CI 0.841 - 0.993, p < 0.001). Fourteen analytes explained 66% of the variance in the postnatal profile (BDNF, C3, C5a, C9, CRP, IL-1β, IL-6, IL-8, IL-18, MCP-1, MIP-1β, MMP-9, RANTES and TNF-α). Of these, IL-8 was associated with altered neurite density index across the white matter skeleton after adjustment for gestational age at birth and at scan (β = 0.221, p = 0.037).

CONCLUSIONS

These findings suggest that IL-8 dysregulation has a role in linking perinatal systemic inflammation and atypical white matter development in preterm infants.

Neonatal and Childhood Outcomes Following Preterm Premature Rupture of Membranes

Preterm premature rupture of membranes (PPROM) is almost uniformly associated with preterm birth and thus sequelae of prematurity explain many of the complications associated with this condition. However, the unique inflammatory environment and oligohydramnios associated with PPROM may impart unique neonatal and childhood morbidity compared with other preterm birth pathways.

Umbilical cord interleukin-6 predicts outcome in very low birthweight infants in a high HIV-burden setting: a prospective cohort study

OBJECTIVES

South Africa has a double burden of high neonatal mortality and maternal HIV prevalence. Common to both is a proinflammatory in utero and perinatal milieu. The aim of this study was to determine cytokine profiles in HIV exposed (HE) and HIV unexposed (HU) very low birthweight (VLBW) infants and to determine whether these were associated with predischarge outcomes.

DESIGN

Single-centre, prospective cohort study conducted from 1 June 2017 to 31 January 2019.

PATIENTS

Inborn infants with birth weight of <1500 g were enrolled and cord blood was collected for interleukin (IL)-6 and tumour necrosis factor alpha (TNF-α) assays. Participants provided informed consent and ethics approval was obtained.

OUTCOME MEASURES

The primary outcome was umbilical cord cytokine levels according to maternal HIV status. Secondary outcomes included death and/or serious neonatal infection, necrotising enterocolitis, intraventricular haemorrhage, periventricular leucomalacia, chronic lung disease and haemodynamically significant patent ductus arteriosus before discharge.

RESULTS

A total of 279 cases were included with 269 cytokine assays performed on 122 HEs and 147 HUs. Median IL-6 levels were 53.0 pg/mL in HEs and 21.0 pg/mL in HUs (p=0.07). Median TNF-α levels were 7.2 pg/mL in HEs and 6.5 pg/mL in HUs (p=0.6). There was significantly more late-onset sepsis in the HE group compared with the HU group (41.2% vs 27.9%) (p=0.03). IL-6 levels were significantly higher for those with any adverse outcome (p=0.006) and death and/or any adverse outcome (p=0.0001). TNF-α levels did not differ according to predischarge outcomes.

CONCLUSION

There is no significant difference in IL-6 and TNF-α levels in cord blood of HE compared with HU VLBWs. However, IL-6 levels are significantly higher in VLBWs with adverse predischarge outcomes, and VLBW HEs are at increased risk of adverse predischarge outcomes compared with HUs, particularly late-onset sepsis.

Immunohistochemical analysis of protective effects of maternal fingolimod on the placenta and fetal lung and brain in chorioamnionitis-induced preterm birth rat model

OBJECTIVES

Fingolimod (FIN) is used for multiple sclerosis treatment and has potential antiapoptotic and anti-inflammatory effects. We aimed at expanding our knowledge on various immunohistochemical markers for elucidating the possible mechanisms of action of fingolimod in the placenta and fetal lung and brain.

METHODS

Sixteen pregnant rats were divided into four groups. On gestational day 17, lipopolysaccharide (LPS) was injected intraperitoneally to induce preterm fetal injury followed by intraperitoneal injection of fingolimod. Hysterotomy for preterm delivery was performed 6 h after fingolimod was injected. The study groups included (1) control, (2) LPS (1 mg/kg), (3) FIN (4 mg/kg), and (4) FIN + LPS. Fetal brain and lung and placenta samples were collected for histopathological examination. Moreover, fetal lungs (surfactant protein-A (SP-A), SP-B, SP-D, caspase-3, and caspase-8), fetal brains (interleukin-10, interleukin-1β, TNF-α, caspase-8, glial fibrillary acidic protein, vimentin, myelin basic protein, and receptor activator of nuclear factor kappa), and placenta tissues (interleukin-10, interleukin-1β, TNF-α, caspase-3, and caspase-8) were immunohistochemically evaluated.

RESULTS

Maternal fingolimod treatment led to attenuation of LPS-induced fetal brain, lung, and placental injury, as indicated by lower immunoexpression of inflammatory markers compared to LPS group (p < .0001 for all comparisons).

CONCLUSION

The findings of the present study confirm the neuroprotective effects of antenatally administered fingolimod, which also significantly improved preterm fetal lung injury and placental inflammation in LPS-exposed preterm pregnancies by possible antiapoptotic and anti-inflammatory effects.

Pathological staging of chorioamnionitis contributes to complications in preterm infants

Objective

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

Methods

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

Results

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

Conclusion

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

Maternal risk score for the prediction of fetal inflammatory response syndrome after preterm premature rupture of membranes

AIM

Preterm premature rupture of membranes (PPROM) is common in preterm births. Fetal inflammatory response syndrome (FIRS) is present in nearly 50% of PPROM cases. We created a risk score to predict FIRS using maternal factors after PPROM.

METHODS

We conducted a retrospective study of singleton pregnancies complicated by PPROM that resulted in delivery at 23-35 weeks of gestation. Antepartum maternal factors and umbilical cord blood interleukin-6 (IL-6) data were analyzed. FIRS was defined as IL-6 > 11 pg/mL.

RESULTS

Umbilical cord blood IL-6 and maternal blood data within 24 h before parturition were available for 158 cases; 66 were diagnosed with FIRS (41.8%; median IL-6, 57.55 pg/mL). We created a risk score (FIRS score) comprising expected delivery weeks (≤30 weeks), maternal C-reactive protein (≥1.2 mg/dL), maternal white blood cell count (≥13 000/μL), corticosteroid use (none) and PROM latency period (≥3 days) from the multivariate logistic regression model predicting FIRS. Receiver operating characteristic curve analysis of the score produced the following results: area under the curve, 0.82; 95% CI, 0.76-0.89; cut-off value, 7.5; sensitivity, 89%; specificity, 63%; positive predictive value, 63% and negative predictive value, 89%. The probability of FIRS according to the categories of the FIRS score was 11% for those with a score of 0-7, 50% for a score of 8-15, and 88% for a score of 16-22.

CONCLUSION

The devised maternal risk score could predict FIRS and be helpful to decide the delivery timing for the cases of PPROM.

Neuroimaging findings associated with the fetal inflammatory response syndrome

The fetal inflammatory response syndrome (FIRS) is a condition whereby the fetus mounts an inflammatory response to intrauterine infection/inflammation. Clinical consequences include preterm premature rupture of membranes (PPROM), spontaneous preterm delivery, neonatal sepsis, bronchopulmonary dysplasia, and brain and other organ injury. Mechanisms leading to brain injury in FIRS have been investigated in animal and human studies. We review the neuroimaging findings of brain injury in FIRS, which overlap those of hypoxic-ischemic injury, and clinical correlation is necessary for a correct diagnosis. FIRS should be considered the primary diagnosis when neuroimaging findings such as periventricular leukomalacia are identified in preterm children born as a consequence of PPROM and spontaneous preterm labor. Additionally, FIRS should be considered in term infants who do not have the most common features of HIE (e.g. a sentinel event). Systematic histopathologic examination of the placenta and umbilical cord and/or detection of characteristic inflammatory markers in such cases are needed to establish the correct diagnosis.

Mechanisms of brain injury in newborn infants associated with the fetal inflammatory response syndrome

The fetal inflammatory response syndrome (FIRS) is characterized by umbilical cord inflammation and elevated fetal pro-inflammatory cytokines. Surviving neonates, especially very preterm infants, have increased rates of neonatal morbidity including neurodevelopmental impairment. The mechanism of brain injury in FIRS is complex and may involve "multiple hits." Exposure to in utero inflammation initiates a cascade of the fetal immune response, where pro-inflammatory cytokines can cause direct injury to oligodendrocytes and neurons. Activation of microglia results in further injury to vulnerable pre-myelinating oligodendrocytes and influences the integrity of the fetal and newborn's blood-brain barrier, resulting in further exposure of the brain to developmental insults. Newborns exposed to FIRS are frequently exposed to additional perinatal and postnatal insults that can result in further brain injury. Future directions should include evaluations for new therapeutic interventions aimed at reducing brain injury by dampening FIRS, inhibition of microglial activation, and regeneration of immature oligodendrocytes.

FIRS: Neonatal considerations

Fetal Inflammatory Response Syndrome (FIRS) is the fetal counterpart of systemic inflammatory response syndrome (SIRS) described in adults. When the fetus is directly exposed to inflammation of the fetal membranes or the placental-fetal circulation, and organs are adversely affected, the disorder is known as FIRS. This syndrome can significantly affect multiple organs with significant short and long term implications for the newborn. In cases of neonatal encephalopathy when no obvious etiology is identified, FIRS needs to be considered. Based on the significant incidence of chorioamnionitis and its potential effects on the newborn, any evidence of maternal, fetal, or neonatal infection should mandate further evaluation of the placenta and membrane histopathology.

Evaluation for the etiology of neonatal encephalopathy and the diagnosis of FIRS

A common disorder managed in the neonatal intensive care unit (NICU) is neonatal encephalopathy (NE). There are multiple causes of NE, including hypoxic-ischemic encephalopathy (HIE) and the fetal inflammatory response syndrome (FIRS). It is important to ascertain the specific cause of NE in an affected child, as it may affect the clinical management and will assist in prognostication. This paper discusses the background of inflammatory damage to the fetal brain, the history of FIRS as a clinical diagnosis, the characteristics of infants with FIRS, and methods to evaluate the etiology of NE.

Therapeutic interventions for fetal inflammatory response syndrome (FIRS)

Fetal inflammatory response syndrome (FIRS) is a condition defined by systemic inflammation in the fetus, a rapid increase of pro-inflammatory cytokines into the fetal circulation (including interleukin-1 and interleukin-6), as well as a cellular response (such as increased neutrophils, monocyte/macrophages, and T cells) and the presence of funisitis. FIRS can lead to death and multisystem organ damage in the fetus and newborn. Brain injuries and subsequent risk of cerebral palsy and cognitive impairments are the most threatening long-term complications. This paper reviews the definition of FIRS, summarizes its associated complications, briefly describes the available methods to study FIRS, and discusses in more detail the potential therapeutic candidates that have been so far studied to protect the fetus/newborn from FIRS and to alleviate its associated complications and sequelae.

Hepcidin, Serum Iron, and Transferrin Saturation in Full-Term and Premature Infants during the First Month of Life: A State-of-the-Art Review of Existing Evidence in Humans

Neonates regulate iron at birth and in early postnatal life. We reviewed literature from PubMed and Ovid Medline containing data on umbilical cord and venous blood concentrations of hepcidin and iron, and transferrin saturation (TSAT), in human neonates from 0 to 1 mo of age. Data from 59 studies were used to create reference ranges for hepcidin, iron, and TSAT for full-term-birth (FTB) neonates over the first month of life. In FTB neonates, venous hepcidin increases 100% over the first month of life (to reach 61.1 ng/mL; 95% CI: 20.1, 102.0 ng/mL) compared with umbilical cord blood (29.7 ng/mL; 95% CI: 21.1, 38.3 ng/mL). Cord blood has a high concentration of serum iron (28.4 μmol/L; 95% CI: 26.0, 31.1 μmol/L) and levels of TSAT (51.7%; 95% CI: 46.5%, 56.9%). After a short-lived immediate postnatal hypoferremia, iron and TSAT rebounded to approximately half the levels in the cord by the end of the first month. There were insufficient data to formulate reference ranges for preterm neonates.

Intra-amniotic inflammation induces preterm birth by activating the NLRP3 inflammasome†

Intra-amniotic inflammation is strongly associated with spontaneous preterm labor and birth, the leading cause of perinatal mortality and morbidity worldwide. Previous studies have suggested a role for the NLRP3 (NLR family pyrin domain-containing protein 3) inflammasome in the mechanisms that lead to preterm labor and birth. However, a causal link between the NLRP3 inflammasome and preterm labor/birth induced by intra-amniotic inflammation has not been established. Herein, using an animal model of lipopolysaccharide-induced intra-amniotic inflammation (IAI), we demonstrated that there was priming of the NLRP3 inflammasome (1) at the transcriptional level, indicated by enhanced mRNA expression of inflammasome-related genes (Nlrp3, Casp1, Il1b); and (2) at the protein level, indicated by greater protein concentrations of NLRP3, in both the fetal membranes and decidua basalis prior to preterm birth. Additionally, we showed that there was canonical activation of the NLRP3 inflammasome in the fetal membranes, but not in the decidua basalis, prior to IAI-induced preterm birth as evidenced by increased protein levels of active caspase-1. Protein concentrations of released IL1β were also increased in both the fetal membranes and decidua basalis, as well as in the amniotic fluid, prior to IAI-induced preterm birth. Finally, using the specific NLRP3 inhibitor, MCC950, we showed that in vivo inhibition of the NLRP3 inflammasome reduced IAI-induced preterm birth and neonatal mortality. Collectively, these results provide a causal link between NLRP3 inflammasome activation and spontaneous preterm labor and birth in the context of intra-amniotic inflammation. We also showed that, by targeting the NLRP3 inflammasome, adverse pregnancy and neonatal outcomes can be significantly reduced.

H. Smith L, Puttonen H, Fyhr IM, Sävman K, Nilsson AK, Klevebro S. Docosahexaenoic Acid and Arachidonic Acid Levels Are Associated with Early Systemic Inflammation in Extremely Preterm Infants

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

Utility of ultrasound assessment in management of pregnancies with preterm prelabor rupture of membranes

OBJECTIVES

To evaluate the utility of ultrasound markers in the management of pregnancies complicated by preterm prelabor rupture of membranes (PPROM) between 23 + 0 and 33 + 6 weeks' gestation, and to assess the ability of ultrasound markers to predict adverse neonatal outcomes.

METHODS

This was a retrospective cohort study of all patients with PPROM between 23 + 0 and 33 + 6 weeks' gestation and latency period (PPROM to delivery) > 48 h, who delivered before 34 weeks' gestation at a tertiary referral center between 2005 and 2017. All patients underwent a non-stress test daily and an ultrasound scan twice a week for assessment of amniotic fluid volume, biophysical profile (BPP) and umbilical artery (UA) pulsatility index (PI). In patients with suspected fetal growth restriction, fetal middle cerebral artery (MCA)-PI was also assessed and the cerebroplacental ratio (CPR) calculated. The last ultrasound examination performed prior to delivery was analyzed. We compared the characteristics and outcomes between women who were delivered owing to clinical suspicion of chorioamnionitis and those who were not delivered for this indication. The primary objective was to evaluate the utility of ultrasound in the management of patients with PPROM. The secondary objective was to assess the diagnostic performance of ultrasound markers (BPP score < 6, oligohydramnios, UA-PI > 95^th percentile, MCA-PI < 5^th percentile, CPR < 5^th percentile) for the prediction of composite adverse neonatal outcome, which was defined as the presence of one or more of: perinatal death, respiratory distress syndrome, periventricular leukomalacia, intraventricular hemorrhage Grade 3 or 4, necrotizing enterocolitis, hypoxic ischemic encephalopathy, neonatal sepsis or neonatal seizures.

RESULTS

A total of 504 women were included in the study, comprising 120 with suspected chorioamnionitis and 384 without. Women with suspected chorioamnionitis, compared with those without, were less likely to be nulliparous (34.2% vs 45.3%; P = 0.03) and more likely to have fever (50.8% vs 2.6%; P < 0.001) and be delivered by Cesarean section (69.2% vs 42.4%; P < 0.001), mainly owing to a history of previous Cesarean section (18.3% vs 9.1%; P = 0.005) and to having non-reassuring fetal heart rate tracings (32.5% vs 14.6%; P < 0.001). No significant differences were found between the two groups with regard to the median amniotic fluid volume, overall BPP score, BPP score < 6, MCA-PI or CPR. Median UA-PI was slightly higher in the suspected-chorioamnionitis group, yet the incidence of UA-PI > 95^th percentile was similar between the two groups. There was a higher incidence of composite adverse neonatal outcome in the group with suspected chorioamnionitis than in the group without (78.3% vs 64.3%, respectively; P = 0.004). However, on logistic regression analysis, none of the ultrasound markers evaluated was found to be associated with chorioamnionitis or composite adverse neonatal outcome, and they all had a poor diagnostic performance for the prediction of chorioamnionitis and composite adverse neonatal outcome.

CONCLUSIONS

Commonly used ultrasound markers in pregnancies complicated by PPROM were similar between women delivered for suspected chorioamnionitis and those delivered for other indications, and performed poorly in predicting composite adverse neonatal outcome. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

PREVALENCE OF POTENTIALLY PATHOGENIC MICROBIOLOGICAL AGENTS IN VAGINAL EXUDATES OF ASYMPTOMATIC PREGNANT WOMEN, BARRANQUILLA, COLOMBIA, 2014-2015

OBJECTIVE

To determine the prevalence of potentially pathogenic microbiological agents in vaginal exudates in a sample of asymptomatic pregnant women in the Department of Atlantico, Colombia.

METHODS

Descriptive cross-sectional study of a sample of asymptomatic pregnant women who attended a private primary healthcare institution in Barranquilla, Colombia, between 2014 and 2015. Pregnant women having received antimicrobial treatment within the last 30 days, with vaginal bleeding, mental disability or immunosuppression, were excluded. Consecutive sampling was performed. The prevalence of colonization time by some of the microbiological agents as well as specific prevalence were estimated: number of women with infection by agent type/number of women at risk assessed.

RESULTS

Overall prevalence was 24.8% (56/226); 55.4% (31/56) was due to vaginitis causal agents, and 44.6% (25/56) to vaginosis. The specific prevalence by type of pathogen, 13.3% (30/226) was vaginitis due to colonization by Candida spp. and 0.4% (1/226) was vaginitis due to T. vaginalis. Bacterial vaginosis (BV) was found in 8.0% (18/226).

CONCLUSIONS

Substantial colonization of the lower genital tract by potentially pathogenic germs is found in pregnant women between 35 and 37 weeks of gestation. Further studies are required in order to determine the benefit of population screening in terms of avoiding poor maternal and perinatal out- comes, and the impact on the resulting overcosts.

Targeting Toll-like receptor-4 to tackle preterm birth and fetal inflammatory injury

Every year, 15 million pregnancies end prematurely, resulting in more than 1 million infant deaths and long-term health consequences for many children. The physiological processes of labour and birth involve essential roles for immune cells and pro-inflammatory cytokines in gestational tissues. There is compelling evidence that the mechanisms underlying spontaneous preterm birth are initiated when a premature and excessive inflammatory response is triggered by infection or other causes. Exposure to pro-inflammatory mediators is emerging as a major factor in the 'fetal inflammatory response syndrome' that often accompanies preterm birth, where unscheduled effects in fetal tissues interfere with normal development and predispose to neonatal morbidity. Toll-like receptors (TLRs) are critical upstream gatekeepers of inflammatory activation. TLR4 is prominently involved through its ability to sense and integrate signals from a range of microbial and endogenous triggers to provoke and perpetuate inflammation. Preclinical studies have identified TLR4 as an attractive pharmacological target to promote uterine quiescence and protect the fetus from inflammatory injury. Novel small-molecule inhibitors of TLR4 signalling, specifically the non-opioid receptor antagonists (+)-naloxone and (+)-naltrexone, are proving highly effective in animal models for preventing preterm birth induced by bacterial mimetic LPS, heat-killed Escherichia coli, or the TLR4-dependent pro-inflammatory lipid, platelet-activating factor (PAF). Here, we summarise the rationale for targeting TLR4 as a master regulator of inflammation in fetal and gestational tissues, and the potential utility of TLR4 antagonists as candidates for preventative and therapeutic application in preterm delivery and fetal inflammatory injury.

Value of cervicovaginal fluid cytokines in prediction of fetal inflammatory response syndrome in pregnancies complicated with preterm premature rupture of membranes (pPROM)

Background Preterm premature rupture of membranes (pPROM) is associated with a high risk of prematurity and complications of fetal inflammatory response syndrome (FIRS). The aim of the study is to determine any correlations between the concentration of selected cytokines contained in the cervicovaginal secretion eluates and in the umbilical cord plasma in patients with pPROM and to find the noninvasive markers of FIRS in order to pinpoint the optimal time of the delivery. Methods The study included 80 patients with pPROM between the 24th and 34th week of gestation. The cervicovaginal fluid and umbilical cord blood were collected. Interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 19 (IL-19) and tumor necrosis factor-α (TNF-α) concentrations were measured in both materials. For the statistical analysis, SigmaStat3.5 software was used. Results There was no direct association in levels of IL-6, TNF-α, IL-10 and IL-19 between the cord blood and cervicovaginal secretions within the studied group. The cut-off point of IL-6 of 26.8 pg/mL in the vaginal fluid had high sensitivity and specificity in order to discriminate between newborns with and without FIRS (81.08%; 76.74%). Conclusion Further studies are needed on a larger group of participants to demonstrate that an elevated concentration of IL-6 above 26.8 pg/mL in the cervicovaginal secretion eluate is an indirect noninvasive marker of FIRS.

Prenatal Maternal Stress Causes Preterm Birth and Affects Neonatal Adaptive Immunity in Mice

Maternal stress is a well-established risk factor for preterm birth and has been associated with adverse neonatal outcomes in the first and subsequent generations, including increased susceptibility to disease and lasting immunological changes. However, a causal link between prenatal maternal stress and preterm birth, as well as compromised neonatal immunity, has yet to be established. To fill this gap in knowledge, we used a murine model of prenatal maternal stress across three generations and high-dimensional flow cytometry to evaluate neonatal adaptive immunity. We report that recurrent prenatal maternal stress induced preterm birth in the first and second filial generations and negatively impacted early neonatal growth. Strikingly, prenatal maternal stress induced a systematic reduction in T cells and B cells, the former including regulatory CD4+ T cells as well as IL-4- and IL-17A-producing T cells, in the second generation. Yet, neonatal adaptive immunity gained resilience against prenatal maternal stress by the third generation. We also show that the rate of prenatal maternal stress-induced preterm birth can be reduced upon cessation of stress, though neonatal growth impairments persisted. These findings provide evidence that prenatal maternal stress causes preterm birth and affects neonatal immunity across generations, adverse effects that can be ameliorated upon cessation.

Oropharyngeal Colostrum Positively Modulates the Inflammatory Response in Preterm Neonates

During the first days of life, premature infants have physiological difficulties swallowing, thereby missing out on the benefits of breastfeeding. The aim of this study is to assess the effects of oropharyngeal mother’s milk administration in the inflammatory signaling of extremely premature infants. Neonates (n = 100) (<32 week’s gestation and/or <1500 g) were divided into two groups: mother’s milk group (n = 48), receiving 0.2 mL of oropharyngeal mother’s milk every 4 h for the first 15 days of life, and a control group (n = 52), not receiving oropharyngeal mother’s milk. Serum concentrations of interleukin (IL) IL-6, IL-8, IL-10, IL-1ra, tumor necrosis factor alpha (TNF-α), and interferón gamma (IFN-γ) were assessed at 1, 3, 15, and 30 days of postnatal life. Maternal and neonatal outcomes were collected. The rate of common neonatal morbidities in both groups was similar. The mother’s milk group achieved full enteral feeding earlier, and showed a decrease in Il-6 on days 15 and 30, in IL-8 on day 30, and in TNF-α and INF-γ on day 15, as well as an increase in IL-1ra on days 3 and 15 and in IL-10 on day 30. Oropharyngeal mother’s milk administration for 15 days decreases the pro-inflammatory state of preterm neonates and provides full enteral nutrition earlier, which could have a positive influence on the development of the immune system and inflammatory response, thereby positively influencing other developmental outcomes.

Prenatal opioid exposure: The next neonatal neuroinflammatory disease

The rates of opioid use disorder during pregnancy have more than quadrupled in the last decade, resulting in numerous infants suffering exposure to opioids during the perinatal period, a critical period of central nervous system (CNS) development. Despite increasing use, the characterization and definition of the molecular and cellular mechanisms of the long-term neurodevelopmental impacts of opioid exposure commencing in utero remains incomplete. Thus, in consideration of the looming public health crisis stemming from the multitude of infants with prenatal opioid exposure entering school age, we undertook an investigation of the effects of perinatal methadone exposure in a novel preclinical model. Specifically, we examined the effects of opioids on the developing brain to elucidate mechanisms of putative neural cell injury, to identify diagnostic biomarkers and to guide clinical studies of outcome and follow-up. We hypothesized that methadone would induce a pronounced inflammatory profile in both dams and their pups, and be associated with immune system dysfunction, sustained CNS injury, and altered cognition and executive function into adulthood. This investigation was conducted using a combination of cellular, molecular, biochemical, and clinically translatable biomarker, imaging and cognitive assessment platforms. Data reveal that perinatal methadone exposure increases inflammatory cytokines in the neonatal peripheral circulation, and reprograms and primes the immune system through sustained peripheral immune hyperreactivity. In the brain, perinatal methadone exposure not only increases chemokines and cytokines throughout a crucial developmental period, but also alters microglia morphology consistent with activation, and upregulates TLR4 and MyD88 mRNA. This increase in neuroinflammation coincides with reduced myelin basic protein and altered neurofilament expression, as well as reduced structural coherence and significantly decreased fractional anisotropy on diffusion tensor imaging. In addition to this microstructural brain injury, adult rats exposed to methadone in the perinatal period have significant impairment in associative learning and executive control as assessed using touchscreen technology. Collectively, these data reveal a distinct systemic and neuroinflammatory signature associated with prenatal methadone exposure, suggestive of an altered CNS microenvironment, dysregulated developmental homeostasis, complex concurrent neural injury, and imaging and cognitive findings consistent with clinical literature. Further investigation is required to define appropriate therapies targeted at the neural injury and improve the long-term outcomes for this exceedingly vulnerable patient population.