Multipotent adult progenitor cells prevent functional impairment and improve development in inflammation driven detriment of preterm ovine lungs.

Background: Perinatal inflammation increases the risk for bronchopulmonary dysplasia in preterm neonates, but the underlying pathophysiological mechanisms remain largely unknown. Given their anti-inflammatory and regenerative capacity, multipotent adult progenitor cells (MAPC) are a promising cell-based therapy to prevent and/or treat the negative pulmonary consequences of perinatal inflammation in the preterm neonate. Therefore, the pathophysiology underlying adverse preterm lung outcomes following perinatal inflammation and pulmonary benefits of MAPC treatment at the interface of prenatal inflammatory and postnatal ventilation exposures were elucidated. Methods: Instrumented ovine fetuses were exposed to intra-amniotic lipopolysaccharide (LPS 5 mg) at 125 days gestation to induce adverse systemic and peripheral organ outcomes. MAPC (10 × 106 cells) or saline were administered intravenously two days post LPS exposure. Fetuses were delivered preterm five days post MAPC treatment and either killed humanely immediately or mechanically ventilated for 72 h. Results: Antenatal LPS exposure resulted in inflammation and decreased alveolar maturation in the preterm lung. Additionally, LPS-exposed ventilated lambs showed continued pulmonary inflammation and cell junction loss accompanied by pulmonary edema, ultimately resulting in higher oxygen demand. MAPC therapy modulated lung inflammation, prevented loss of epithelial and endothelial barriers and improved lung maturation in utero. These MAPC-driven improvements remained evident postnatally, and prevented concomitant pulmonary edema and functional loss. Conclusion: In conclusion, prenatal inflammation sensitizes the underdeveloped preterm lung to subsequent postnatal inflammation, resulting in injury, disturbed development and functional impairment. MAPC therapy partially prevents these changes and is therefore a promising approach for preterm infants to prevent adverse pulmonary outcomes.

Antenatal Ureaplasma Infection Causes Colonic Mucus Barrier Defects: Implications for Intestinal Pathologies.

Chorioamnionitis is a risk factor for necrotizing enterocolitis (NEC). Ureaplasma parvum (UP) is clinically the most isolated microorganism in chorioamnionitis, but its pathogenicity remains debated. Chorioamnionitis is associated with ileal barrier changes, but colonic barrier alterations, including those of the mucus barrier, remain under-investigated, despite their importance in NEC pathophysiology. Therefore, in this study, the hypothesis that antenatal UP exposure disturbs colonic mucus barrier integrity, thereby potentially contributing to NEC pathogenesis, was investigated. In an established ovine chorioamnionitis model, lambs were intra-amniotically exposed to UP or saline for 7 d from 122 to 129 d gestational age. Thereafter, colonic mucus layer thickness and functional integrity, underlying mechanisms, including endoplasmic reticulum (ER) stress and redox status, and cellular morphology by transmission electron microscopy were studied. The clinical significance of the experimental findings was verified by examining colon samples from NEC patients and controls. UP-exposed lambs have a thicker but dysfunctional colonic mucus layer in which bacteria-sized beads reach the intestinal epithelium, indicating undesired bacterial contact with the epithelium. This is paralleled by disturbed goblet cell MUC2 folding, pro-apoptotic ER stress and signs of mitochondrial dysfunction in the colonic epithelium. Importantly, the colonic epithelium from human NEC patients showed comparable mitochondrial aberrations, indicating that NEC-associated intestinal barrier injury already occurs during chorioamnionitis. This study underlines the pathogenic potential of UP during pregnancy; it demonstrates that antenatal UP infection leads to severe colonic mucus barrier deficits, providing a mechanistic link between antenatal infections and postnatal NEC development.

Post-COVID in women after SARS-CoV-2 infection during pregnancy - a pilot study with follow-up data from the COVID-19-related Obstetric and Neonatal Outcome Study (CRONOS).

BACKGROUND: Pregnant women are at an increased risk of severe COVID-19 and adverse pregnancy outcomes; data on maternal long-term outcome is scarce. We analyzed long-term follow-ups on women who experienced a SARS-CoV-2 infection during pregnancy to evaluate post-COVID symptoms, particularly fatigue, and their association with quality of life (QoL). METHODS: 773 women who enrolled in the CRONOS registry between April 2020 and August 2021 were contacted for follow-up from December 2022 to April 2023. Data was gathered through a web-based questionnaire. Subsequently, study coordinators matched the follow-up data with the existing CRONOS data. RESULTS: 110/773 (14%) women provided data. 20.9% experienced only acute symptoms during their SARS-CoV-2 infection in pregnancy, while 2.7% women experienced symptoms lasting longer than 4 weeks (long COVID). Symptoms lasting longer than 12 weeks (post-COVID) were reported by 63.6% women and occurred more often after severe COVID-19. Fatigue was the most frequently reported symptom (88%), with 55% of women still experiencing it more than one year after initial infection. 76% of women rated their QoL as "good" or "very good". Women experiencing post-COVID reported a significantly lower QoL. CONCLUSION: This is the first German long-term data on women after SARS-CoV-2 infection during pregnancy, showing a high rate of post-COVID, a persistence of fatigue, and the impact on QoL. Continuous monitoring of pregnant women with COVID-19 is needed to develop comprehensive management strategies.

Long-Term Outcome of Neonates and Infants whose Mothers Tested Positive for SARS-CoV-2 during Pregnancy - a Pilot of the Post-CRONOS Project.

OBJECTIVE: Long-term effects on infants of mothers with SARS-CoV-2 infection during pregnancy are increasingly discussed in the literature. Besides potential neurodevelopment impairments after intrauterine SARS-CoV-2 exposure, there might be differences in the postnatal pediatric care of those children, like the timing of preventive medical examinations (PME) or vaccinations. In this first national long-term follow-up study of women included in the CRONOS registry, we describe maternal impressions of their child´s development and the prevalence of regulatory disorders, and we analyze the timing of PMEs and vaccinations. METHODS: 773 women who were enrolled between April 3, 2020, and August 24, 2021, in the CRONOS registry were eligible to be contacted by the study coordinators and asked to fill out a web-based questionnaire. RESULTS: 110/773 (14%) women completed the questionnaire. Their children were between the ages of 12 and 31 months (median 20 months). All mothers were satisfied with their child´s development, milestones were achieved in a timely fashion. The reported prevalence for excessive crying, sleeping, and feeding disorders was 11%, 18-32%, and 7%, respectively. PMEs were mostly not delayed, but only 54% of infants received their first vaccination within their first 60 days of life. DISCUSSION: In summary, our exploratory findings suggest that developmental milestones in infancy are reached in time after maternal SARS-CoV-2 infection during pregnancy. However, there are effects on the implementation of PMEs and vaccinations. EINFüHRUNG: In der Literatur werden zunehmend potenzielle Langzeitfolgen für Säuglinge nach intrauteriner SARS-CoV-2-Exposition diskutiert. Neben möglichen Beeinträchtigungen der neurologischen Entwicklung können Unterschiede in der pädiatrischen postnatalen Betreuung bei diesen Kindern z. B. bei der Durchführung von Vorsorgeuntersuchungen (sog. U´s) oder Impfungen bestehen. In dieser ersten nationalen Langzeit-Follow-up-Studie aus dem CRONOS-Register beschreiben wir mütterliche Eindrücke zur Entwicklung ihres Kindes, sowie die Prävalenz von Regulationsstörungen. Wir analysieren den Zeitpunkt von U´s und Impfungen. METHODEN: 773 Frauen, die zwischen dem 03.04.2020 und dem 24.08.2021 in CRONOS aufgenommen wurden, wurden von den Studienkoordinatoren kontaktiert und gebeten, einen webbasierten Fragebogen auszufüllen. ERGEBNISSE: 110/773 (14%) Frauen füllten den Fragebogen aus, ihre Kinder waren zwischen 12 und 31 Monate alt (Median 20 Monate). Alle Mütter waren mit der Entwicklung ihres Kindes zufrieden, Meilensteine der Entwicklung wurden zeitgerecht erreicht. Die berichtete Prävalenz für exzessives Schreien, Schlaf- und Fütterstörungen betrug 11%, 18-32% bzw. 7%. U´s wurden meist zeitgerecht durchgeführt, aber nur 54% der Säuglinge erhielten ihre erste Impfung innerhalb der ersten 60 Lebenstage. DISKUSSION: Zusammenfassend deuten unsere explorativen Ergebnisse darauf hin, dass Entwicklungsmeilensteine im Säuglingsalter nach mütterlicher SARS-CoV-2-Infektion in der Schwangerschaft rechtzeitig erreicht werden. Es zeigen sich jedoch Auswirkungen auf die Durchführung von Vorsorgen und Impfungen.

Vertical transmission of SARS-CoV-2 - data from the German COVID-19 related obstetric and neonatal outcome study (CRONOS).

OBJECTIVES: We aimed to determine the frequency of SARS-CoV-2 positivity in newborns born to mothers with peripartum SARS-CoV-2 infection in a German cohort, to identify potential risk factors associated with neonatal SARS-CoV-2 infection, and to present short-term outcomes of newborns with vertical transmission of SARS-CoV-2. METHODS: Data on women with SARS-CoV-2 infection occurring anytime during their pregnancy was gathered prospectively within the CRONOS registry. From April 2020 to February 2023 a total of 8,540 women had been registered. The timing and the probability of mother-to-child transmission in neonates born to women with perinatal SARS-CoV-2 infection were classified using the WHO classification system. The severity of maternal infection, maternal vaccination status, type of dominant virus, and perinatal outcome parameters were analyzed as potential risk factors for neonatal SARS-CoV-2 infection. RESULTS: 6.3 % resp. 42.9 % of tested newborns and stillbirths were SARS-CoV-2 positive. 2.1 % of newborns with confirmed and possible SARS-CoV-2 infection were identified. Severe maternal COVID-19 (odds ratio 4.4, 95 % confidence interval 1.8-11.1) and maternal infection with the Delta virus (OR 3.2, 1.4-7.7) were associated with neonatal SARS-CoV-2 infection. Newborns with a confirmed or possible infection were significantly more often admitted to the NICU (65.2 % neonatal infection vs. 27.5 % non, p<0.001). CONCLUSIONS: The rate of neonatal SARS-CoV-2 positivity was higher in our cohort than previously reported, neonatal SARS-CoV-2 infections were rare. Our data emphasizes confirmative testing should be performed in newborns of SARS-CoV-2 infected mothers to identify neonatal SARS-CoV-2 infection as an underlying pathology leading to NICU admission.

Cerebral near-infrared spectroscopy for early recognition of impending cardiac tamponade in a preterm neonate.

Cardiac tamponade is a rare but life-threatening complication of umbilical venous catheter (UVC) placement in neonates. Mortality rates are high; therefore, early diagnosis is important. We present a case of a preterm infant with a UVC in situ who underwent a laparotomy on the first day of life for pneumoperitoneum secondary to meconium ileus. The operation was uneventful; however, 2 hours after surgery, the patient developed cardiac tamponade, requiring resuscitation and pericardiocentesis. In retrospect, near-infrared spectroscopy (NIRS) showed a gradual decline in cerebral oxygenation (crSO2) in the 30 min prior to the cardiac arrest, while other vital signs were within normal ranges. Our case demonstrates that cerebral NIRS monitoring can serve as an additional clinical marker for early recognition of impending cardiac tamponade.

Doxapram versus placebo in preterm newborns: a study protocol for an international double blinded multicentre randomized controlled trial (DOXA-trial).

BACKGROUND: Apnoea of prematurity (AOP) is one of the most common diagnoses among preterm infants. AOP often leads to hypoxemia and bradycardia which are associated with an increased risk of death or disability. In addition to caffeine therapy and non-invasive respiratory support, doxapram might be used to reduce hypoxemic episodes and the need for invasive mechanical ventilation in preterm infants, thereby possibly improving their long-term outcome. However, high-quality trials on doxapram are lacking. The DOXA-trial therefore aims to investigate the safety and efficacy of doxapram compared to placebo in reducing the composite outcome of death or severe disability at 18 to 24 months corrected age. METHODS: The DOXA-trial is a double blinded, multicentre, randomized, placebo-controlled trial conducted in the Netherlands, Belgium and Canada. A total of 396 preterm infants with a gestational age below 29 weeks, suffering from AOP unresponsive to non-invasive respiratory support and caffeine will be randomized to receive doxapram therapy or placebo. The primary outcome is death or severe disability, defined as cognitive delay, cerebral palsy, severe hearing loss, or bilateral blindness, at 18-24 months corrected age. Secondary outcomes are short-term neonatal morbidity, including duration of mechanical ventilation, bronchopulmonary dysplasia and necrotising enterocolitis, hospital mortality, adverse effects, pharmacokinetics and cost-effectiveness. Analysis will be on an intention-to-treat principle. DISCUSSION: Doxapram has the potential to improve neonatal outcomes by improving respiration, but the safety concerns need to be weighed against the potential risks of invasive mechanical ventilation. It is unknown if the use of doxapram improves the long-term outcome. This forms the clinical equipoise of the current trial. This international, multicentre trial will provide the needed high-quality evidence on the efficacy and safety of doxapram in the treatment of AOP in preterm infants. TRIAL REGISTRATION: ClinicalTrials.gov NCT04430790 and EUDRACT 2019-003666-41. Prospectively registered on respectively June and January 2020.

Placing Ureaplasma within the Context of Bronchopulmonary Dysplasia Endotypes and Phenotypes.

Different pathophysiological pathways (endotypes), leading to very preterm birth may result in distinct clinical phenotypes of bronchopulmonary dysplasia (BPD). Ureaplasma is a unique player in the pathogenesis of BPD. The interaction between factors inherent to Ureaplasma (virulence, bacterial load, duration of exposure), and to the host (immune response, infection clearance, degree of prematurity, respiratory support, concomitant infections) may contribute to BPD development in a variable manner. The data reviewed herein support the hypothesis that Ureaplasma, as a representative of the infectious/inflammatory endotype, may produce pulmonary damage predominantly in parenchyma, interstitium, and small airways. In contrast, Ureaplasma may have a very limited role in the pathogenesis of the vascular phenotype of BPD. In addition, if Ureaplasma is a key factor in BPD pathogenesis, its eradication by macrolides should prevent BPD. However, various meta-analyses do not show consistent evidence that this is the case. The limitations of current definitions and classifications of BPD, based on respiratory support needs instead of pathophysiology and phenotypes, may explain this and other failures in strategies aimed to prevent BPD. The precise mechanisms through which Ureaplasma infection leads to altered lung development and how these pathways can result in different BPD phenotypes warrant further investigation.

Ureaplasma-Driven Neonatal Neuroinflammation: Novel Insights from an Ovine Model.

Ureaplasma species (spp.) are considered commensals of the adult genitourinary tract, but have been associated with chorioamnionitis, preterm birth, and invasive infections in neonates, including meningitis. Data on mechanisms involved in Ureaplasma-driven neuroinflammation are scarce. The present study addressed brain inflammatory responses in preterm lambs exposed to Ureaplasma parvum (UP) in utero. 7 days after intra-amniotic injection of UP (n = 10) or saline (n = 11), lambs were surgically delivered at gestational day 128-129. Expression of inflammatory markers was assessed in different brain regions using qRT-PCR and in cerebrospinal fluid (CSF) by multiplex immunoassay. CSF was analyzed for UP presence using ureB-based real-time PCR, and MRI scans documented cerebral white matter area and cortical folding. Cerebral tissue levels of atypical chemokine receptor (ACKR) 3, caspases 1-like, 2, 7, and C-X-C chemokine receptor (CXCR) 4 mRNA, as well as CSF interleukin-8 protein concentrations were significantly increased in UP-exposed lambs. UP presence in CSF was confirmed in one animal. Cortical folding and white matter area did not differ among groups. The present study confirms a role of caspases and the transmembrane receptors ACKR3 and CXCR4 in Ureaplasma-driven neuroinflammation. Enhanced caspase 1-like, 2, and 7 expression may reflect cell death. Increased ACKR3 and CXCR4 expression has been associated with inflammatory central nervous system (CNS) diseases and impaired blood-brain barrier function. According to these data and previous in vitro findings from our group, we speculate that Ureaplasma-induced caspase and receptor responses affect CNS barrier properties and thus facilitate neuroinflammation.

Antenatal Ureaplasma infection induces ovine small intestinal goblet cell defects: a strong link with NEC pathology.

Disruption of the intestinal mucus barrier and intestinal epithelial endoplasmic reticulum (ER) stress contribute to necrotizing enterocolitis (NEC). Previously, we observed intestinal goblet cell loss and increased intestinal epithelial ER stress following chorioamnionitis. Here, we investigated how chorioamnionitis affects goblet cells by assessing their cellular characteristics. Importantly, goblet cell features are compared with those in clinical NEC biopsies. Mucus thickness was assessed as read-out of goblet cell function. Fetal lambs were intra-amniotically (IA) infected for 7d at 122 gestational age with Ureaplasma parvum serovar-3, the main microorganism clinically associated with chorioamnionitis. After preterm delivery, mucus thickness, goblet cell numbers, gut inflammation, epithelial proliferation and apoptosis and intestinal epithelial ER stress were investigated in the terminal ileum. Next, goblet cell morphological alterations (TEM) were studied and compared to human NEC samples. Ileal mucus thickness and goblet cell numbers were elevated following IA UP exposure. Increased pro-apoptotic ER stress, detected by elevated CHOP-positive cell counts and disrupted organelle morphology of secretory cells in the intestinal epithelium, was observed in IA UP exposed animals. Importantly, comparable cellular morphological alterations were observed in the ileum from NEC patients. In conclusion, UP-driven chorioamnionitis leads to a thickened ileal mucus layer and mucus hypersecretion from goblet cells. Since this was associated with pro-apoptotic ER stress and organelle disruption, mucus barrier alterations seem to occur at the expense of goblet cell resilience and may therefore predispose to detrimental intestinal outcomes. The remarkable overlap of these in utero findings with observations in NEC patients underscores their clinical relevance.

Closed-Loop Control of Arterial CO2 in Mechanical Ventilation of Neonates.

During mechanical ventilation of the neonate the main goal is to stabilize respiratory function of the often premature lungs. Ventilating the patient without inflicting harm is then the subordinated next goal. Ideally the arterial partial pressure of CO2 lays within a normocapnic range and fluctuations are kept minimal. By closely monitoring CO2 and controlling ventilation parameters accordingly, CO2 levels in the blood can be managed. We present an approach consisting of a cascaded controller for arterial CO2 by approximating arterial partial pressure PaCO2 from end-tidal PetCO2. As a proof of concept, feasibility of the controller was first evaluated on a mathematical patient model and subsequently in-vivo in lamb experiments. The controller is able to regulate CO2 into a normocapnic range in both setups with satisfactory stationarity within the target range. Estimation of the arterial partial pressure of CO2 remains a critical aspect that needs to be further investigated. Clinical relevance-Closed-loop control of CO2 in mechanical ventilation aims to avoid PaC O2 extremes and to reduce fluctuations. Both are a relevant risk factors especially for neurological complications among preterm newborns.

Management of severe neonatal respiratory distress due to vertical transmission of severe acute respiratory syndrome coronavirus 2: a case report.

BACKGROUND: Neonates with severe acute respiratory syndrome coronavirus 2 infection are usually asymptomatic or have mild to moderate symptoms. Acute respiratory distress syndrome due to severe acute respiratory syndrome coronavirus 2 with respiratory insufficiency is rare. Therefore, information about the best intensive care strategy for neonates requiring mechanical ventilation is lacking. We report a neonatal case of severe acute respiratory distress syndrome, probably due to vertical transmission of severe acute respiratory syndrome coronavirus 2, complicated by Staphylococcus aureus sepsis. We aim to inform pediatric providers on the clinical course and acute management considerations in coronavirus disease-related neonatal acute respiratory distress syndrome. CASE PRESENTATION: A late preterm (gestational age 36 0/7 weeks) Caucasian girl was born from a severe acute respiratory syndrome coronavirus 2-positive mother and tested positive for severe acute respiratory syndrome coronavirus 2 at 19 hours after birth. She developed acute respiratory distress syndrome requiring intensive care admission and mechanical ventilation. The clinical course was complicated by S. aureus pneumonia and bacteremia. Multimodal management included well-established interventions for respiratory distress syndrome such as surfactant therapy, high-frequency oscillatory ventilation, and inhaled nitric oxide, combined with therapies extrapolated from adult care for severe acute respiratory syndrome coronavirus 2 patients such as dexamethasone, coronavirus disease 2019-specific immunoglobins, and prophylactic low-molecular-weight heparin. The neonate was successfully weaned from the ventilator and improved clinically. CONCLUSION: This case shows a rare but serious neonatal severe acute respiratory syndrome coronavirus 2 infection, leading to severe acute respiratory distress syndrome. Because of limited therapy guidelines for neonates, we suggest multimodal management with awareness of the possibility of S. aureus coinfection, to treat this age group successful.

A20 Is Increased in Fetal Lung in a Sheep LPS Model of Chorioamnionitis.

Chorioamnionitis is associated with an increased risk of preterm birth and aggravates adverse outcomes such as BPD. Development of BPD is associated with chronic inflammatory reactions and oxidative stress in the airways which may be antenatally initiated by chorioamnionitis. A20 is an immunomodulatory protein involved in the negative feedback regulation of inflammatory reactions and is a possible regulator protein in oxidative stress reactions. The influence of chorioamnionitis on A20 gene regulation in the fetal lung is unknown. We characterized the influence of LPS and proinflammatory cytokines on A20 expression in human lung endothelial (HPMEC-ST1.6R) and epithelial (A549) cells in vitro by real-time PCR and/or western blotting and used a sheep model of LPS-induced chorioamnionitis for in vivo studies. To study the functional role of A20, endogenous A20 was overexpressed in HPMEC-ST1.6R and A549 cells. LPS induced proinflammatory cytokines in HPMEC-ST1.6R and A549 cells. Both LPS and/or proinflammatory cytokines elevated A20 at transcriptional and translational levels. Intra-amniotic LPS transiently increased IL-1ß, IL-6, IL-8, and TNF-α mRNA levels in fetal lamb lungs, associated with an increase in A20 mRNA and protein levels. Overexpression of A20 reduced proinflammatory cytokines in vitro. Repeated LPS exposure induced LPS tolerance for proinflammatory cytokines and A20 in vitro and in vivo. Antenatal inflammation induced a transient increase in proinflammatory cytokines in the preterm fetal lung. The expression of proinflammatory cytokines increased expression of A20. Elevated A20 may have a protective role by downregulating chorioamnionitis-triggered fetal lung inflammation. A20 may be a novel target for pharmacological interventions to prevent chorioamnionitis-induced airway inflammation and lung damage, which can result in BPD later in life.

Acute Lung Functional and Airway Remodeling Effects of an Inhaled Highly Selective Phosphodiesterase 4 Inhibitor in Ventilated Preterm Lambs Exposed to Chorioamnionitis.

Phosphodiesterase (PDE) inhibition has been identified in animal studies as a new treatment option for neonatal lung injury, and as potentially beneficial for early lung development and function. However, our group could show that the inhaled PDE4 inhibitor GSK256066 could have dose-dependent detrimental effects and promote lung inflammation in the premature lung. In this study, the effects of a high and a low dose of GSK256066 on lung function, structure and alveolar development were investigated. In a triple hit lamb model of Ureaplasma-induced chorioamnionitis, prematurity, and mechanical ventilation, 21 animals were treated as unventilated (NOVENT) or 24 h ventilated controls (Control), or with combined 24 h ventilation and low dose (iPDE1) or high dose (iPDE10) treatment with inhaled GSK 256066. We found that high doses of an inhaled PDE4 inhibitor impaired oxygenation during mechanical ventilation. In this group, the budding of secondary septae appeared to be decreased in the preterm lung, suggesting altered alveologenesis. Ventilation-induced structural and functional changes were only modestly ameliorated by a low dose of PDE4 inhibitor. In conclusion, our findings indicate the narrow therapeutic window of PDE4 inhibitors in the developing lung.

Management of Intrahepatic Cholestasis of Pregnancy: Recommendations of the Working Group on Obstetrics and Prenatal Medicine - Section on Maternal Disorders.

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease specific to pregnancy. The cardinal symptom of pruritus and a concomitant elevated level of bile acids in the serum and/or alanine aminotransferase (ALT) are suggestive for the diagnosis. Overall, the maternal prognosis is good. The fetal outcome depends on the bile acid level. ICP is associated with increased risks for adverse perinatal outcomes, including preterm delivery, meconium-stained amniotic fluid, and stillbirth. Acute fetal asphyxia and not chronic uteroplacental dysfunction leads to stillbirth. Therefore, predictive fetal monitoring is not possible. While medication with ursodeoxycholic acid (UDCA) improves pruritus, it has not been shown to affect fetal outcome. The indication for induction of labour depends on bile acid levels and gestational age. There is a high risk of recurrence in subsequent pregnancies.

Screening of Chorioamnionitis Using Volatile Organic Compound Detection in Exhaled Breath: A Pre-clinical Proof of Concept Study.

Chorioamnionitis is a major risk factor for preterm birth and an independent risk factor for postnatal morbidity for which currently successful therapies are lacking. Emerging evidence indicates that the timing and duration of intra-amniotic infections are crucial determinants for the stage of developmental injury at birth. Insight into the dynamical changes of organ injury after the onset of chorioamnionitis revealed novel therapeutic windows of opportunity. Importantly, successful development and implementation of therapies in clinical care is currently impeded by a lack of diagnostic tools for early (prenatal) detection and surveillance of intra-amniotic infections. In the current study we questioned whether an intra-amniotic infection could be accurately diagnosed by a specific volatile organic compound (VOC) profile in exhaled breath of pregnant sheep. For this purpose pregnant Texel ewes were inoculated intra-amniotically with Ureaplasma parvum and serial collections of exhaled breath were performed for 6 days. Ureaplasma parvum infection induced a distinct VOC-signature in expired breath of pregnant sheep that was significantly different between day 0 and 1 vs. day 5 and 6. Based on a profile of only 15 discriminatory volatiles, animals could correctly be classified as either infected (day 5 and 6) or not (day 0 and 1) with a sensitivity of 83% and a specificity of 71% and an area under the curve of 0.93. Chemical identification of these distinct VOCs revealed the presence of a lipid peroxidation marker nonanal and various hydrocarbons including n-undecane and n-dodecane. These data indicate that intra-amniotic infections can be detected by VOC analyses of exhaled breath and might provide insight into temporal dynamics of intra-amniotic infection and its underlying pathways. In particular, several of these volatiles are associated with enhanced oxidative stress and undecane and dodecane have been reported as predictive biomarker of spontaneous preterm birth in humans. Applying VOC analysis for the early detection of intra-amniotic infections will lead to appropriate surveillance of these high-risk pregnancies, thereby facilitating appropriate clinical course of action including early treatment of preventative measures for pre-maturity-associated morbidities.

Sequential Exposure to Antenatal Microbial Triggers Attenuates Alveolar Growth and Pulmonary Vascular Development and Impacts Pulmonary Epithelial Stem/Progenitor Cells.

Perinatal inflammatory stress is strongly associated with adverse pulmonary outcomes after preterm birth. Antenatal infections are an essential perinatal stress factor and contribute to preterm delivery, induction of lung inflammation and injury, pre-disposing preterm infants to bronchopulmonary dysplasia. Considering the polymicrobial nature of antenatal infection, which was reported to result in diverse effects and outcomes in preterm lungs, the aim was to examine the consequences of sequential inflammatory stimuli on endogenous epithelial stem/progenitor cells and vascular maturation, which are crucial drivers of lung development. Therefore, a translational ovine model of antenatal infection/inflammation with consecutive exposures to chronic and acute stimuli was used. Ovine fetuses were exposed intra-amniotically to Ureaplasma parvum 42 days (chronic stimulus) and/or to lipopolysaccharide 2 or 7 days (acute stimulus) prior to preterm delivery at 125 days of gestation. Pulmonary inflammation, endogenous epithelial stem cell populations, vascular modulators and morphology were investigated in preterm lungs. Pre-exposure to UP attenuated neutrophil infiltration in 7d LPS-exposed lungs and prevented reduction of SOX-9 expression and increased SP-B expression, which could indicate protective responses induced by re-exposure. Sequential exposures did not markedly impact stem/progenitors of the proximal airways (P63+ basal cells) compared to single exposure to LPS. In contrast, the alveolar size was increased solely in the UP+7d LPS group. In line, the most pronounced reduction of AEC2 and proliferating cells (Ki67+) was detected in these sequentially UP + 7d LPS-exposed lambs. A similar sensitization effect of UP pre-exposure was reflected by the vessel density and expression of vascular markers VEGFR-2 and Ang-1 that were significantly reduced after UP exposure prior to 2d LPS, when compared to UP and LPS exposure alone. Strikingly, while morphological changes of alveoli and vessels were seen after sequential microbial exposure, improved lung function was observed in UP, 7d LPS, and UP+7d LPS-exposed lambs. In conclusion, although sequential exposures did not markedly further impact epithelial stem/progenitor cell populations, re-exposure to an inflammatory stimulus resulted in disturbed alveolarization and abnormal pulmonary vascular development. Whether these negative effects on lung development can be rescued by the potentially protective responses observed, should be examined at later time points.

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.