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.

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.

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.

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.

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.

Chorioamnionitis induces changes in ovine pulmonary endogenous epithelial stem/progenitor cells in utero.

BACKGROUND: Chorioamnionitis, an intrauterine infection of the placenta and fetal membranes, is a common risk factor for adverse pulmonary outcomes in premature infants including BPD, which is characterized by an arrest in alveolar development. As endogenous epithelial stem/progenitor cells are crucial for organogenesis and tissue repair, we examined whether intrauterine inflammation negatively affects these essential progenitor pools. METHODS: In an ovine chorioamnionitis model, fetuses were intra-amniotically exposed to LPS, 2d or 7d (acute inflammation) before preterm delivery at 125d of gestation, or to intra-amniotic Ureaplasma parvum for 42d (chronic inflammation). Lung function, pulmonary endogenous epithelial stem/progenitor pools, and downstream functional markers were studied. RESULTS: Lung function was improved in the 7d LPS and 42d Ureaplasma groups. However, intrauterine inflammation caused a loss of P63+ basal cells in proximal airways and reduced SOX-9 expression and TTF-1+ Club cells in distal airways. Attenuated type-2 cell numbers were associated with lower proliferation and reduced type-1 cell marker Aqp5 expression, indicative for impaired progenitor function. Chronic Ureaplasma infection only affected distal airways, whereas acute inflammation affected stem/progenitor populations throughout the lungs. CONCLUSIONS: Acute and chronic prenatal inflammation improve lung function at the expense of stem/progenitor alterations that potentially disrupt normal lung development, thereby predisposing to adverse postnatal outcomes. IMPACT: In this study, prenatal inflammation improved lung function at the expense of stem/progenitor alterations that potentially disrupt normal lung development, thereby predisposing to adverse postnatal outcomes. Importantly, we demonstrate that these essential alterations can already be initiated before birth. So far, stem/progenitor dysfunction has only been shown postnatally. This study indicates that clinical protocols to target the consequences of perinatal inflammatory stress for the immature lungs should be initiated as early as possible and ideally in utero. Within this context, our data suggest that interventions, which promote function or repair of endogenous stem cells in the lungs, hold great promise.

Prematurity, perinatal inflammatory stress, and the predisposition to develop chronic kidney disease beyond oligonephropathy.

Prematurity and perinatal stress, such as intrauterine growth restriction (IUGR) and chorioamnionitis, are pathological processes creating an impaired intrauterine environment. These intrauterine factors are associated with the development of proteinuria, hypertension, and chronic kidney disease (CKD) later in life. Initially, this was thought to be secondary to oligonephropathy, subsequent glomerular hypertrophy, and hyperfiltration, leading to glomerulosclerosis, a further decrease in nephron number, and finally CKD. Nowadays, there is increasing evidence that prematurity and perinatal stress affect not only nephron endowment but also the maturation of podocytes and vasculogenesis. IUGR is associated with podocyte damage and an aggravated course of nephrotic syndrome. Moreover, preterm birth and IUGR are known to cause upregulation of the postnatal renin-angiotensin system, resulting in hypertension. Chorioamnionitis causes damage to the glomeruli, thereby predisposing to the development of glomerulosclerosis. This review aims to summarize current knowledge on the influence of prematurity, IUGR, and chorioamnionitis on the development of different glomerular structures. After summarizing human and experimental data on low nephron number in general, a specific focus on the current understanding of podocyte and glomerular capillary formation in relation to prematurity and different causes of perinatal stress is presented.

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.

Cholesterol acceptor capacity is preserved by different mechanisms in preterm and term fetuses.

Fetal serum cholesterol and lipoprotein concentrations differ between preterm and term born neonates. An imbalance of the flow of cholesterol from the sites of synthesis or efflux from cells of peripheral organs to the liver, the reverse cholesterol transport (RCT), is linked to atherosclerosis and cardiovascular disease (CVD). Preterm delivery is a risk factor for the development of CVD. Thus, we hypothesized that RCT is affected by a diminished cholesterol acceptor capacity in preterm as compared to term fetuses. Cholesterol efflux assays were performed in RAW264.7, HepG2, and HUVEC cell lines. In the presence and absence of ABC transporter overexpression by TO-901317, umbilical cord sera of preterm and term born neonates (n = 28 in both groups) were added. Lipid components including high density lipoprotein (HDL), low density lipoprotein (LDL), apolipoprotein A1, and apolipoprotein E were measured and related to fractional cholesterol efflux values. We found overall, fractional cholesterol efflux to remain constant between the study groups, and over gestational ages at delivery, respectively. However, correlation analysis revealed cholesterol efflux values to be predominantly related to HDL concentration at term, while in preterm neonates, cholesterol efflux was mainly associated with LDL In conclusion cholesterol acceptor capacity during fetal development is kept in a steady state with different mechanisms and lipid fractions involved at distinct stages during the second half of fetal development. However, RCT mechanisms in preterm neonates seem not to be involved in the development of CVD later in life suggesting rather changes in the lipoprotein pattern causative.

Fully automated predictive intelligent control of oxygenation (PRICO) in resuscitation and ventilation of preterm lambs.

BACKGROUND: Hyperoxia and hypoxia influence morbidity and mortality of preterm infants. Automated closed-loop control of the fraction of inspired oxygen (FiO(2)) has been shown to facilitate oxygen supplementation in the neonatal intensive care unit (NICU), but has not yet been tested during preterm resuscitation. We hypothesized that fully automated FiO(2) control based on predefined oxygen saturation (SpO(2)) targets was applicable in both preterm resuscitation and ventilation. METHODS: Twenty-two preterm lambs were operatively delivered and intubated in a modified EXIT procedure. They were randomized to receive standardized resuscitation with either automated or manual FiO(2) control, targeting SpO(2) according to the Dawson curve in the first 10 min and SpO(2) 90-95% hereafter. Automated FiO(2) control also was applied during surfactant replacement therapy and subsequent ventilation. RESULTS: Time within target range did not differ significantly between manual and automated FiO(2) control during resuscitation, however automated FiO(2) control significantly avoided hyperoxia. Automated FiO(2) control was feasible during surfactant replacement and kept SpO(2) within target range significantly better than manual control during subsequent ventilation. CONCLUSION: In our model, fully automated FiO(2) control was feasible in rapidly changing physiologic conditions during postnatal resuscitation and prevented hyperoxia. We conclude that closed loop FiO(2) control is a promising tool for the delivery room.

Nebulization of Poractant alfa via a vibrating membrane nebulizer in spontaneously breathing preterm lambs with binasal continuous positive pressure ventilation.

BACKGROUND: Surfactant replacement therapy is the gold standard treatment of neonatal respiratory distress (RDS). Nebulization is a noninvasive mode of surfactant administration. We administered Poractant alfa (Curosurf) via a vibrating perforated membrane nebulizer (eFlow Neonatal Nebulizer) to spontaneously breathing preterm lambs during binasal continuous positive pressure ventilation (CPAP). METHODS: Sixteen preterm lambs were operatively delivered at a gestational age of 133 ± 1 d (term ~150 d), and connected to CPAP applied via customized nasal prongs. Nebulization was performed (i) with saline or (ii) with surfactant for 3 h in humidified or (iii) nonhumidified air, and with surfactant (iv) for 60 min or (v) for 30 min. We measured arterial oxygenation, lung gas volumes and surfactant pool size and deposition. RESULTS: Nebulization of surfactant in humidified air for 3 h improved oxygenation and lung function, and surfactant was preferentially distributed to the lower lung lobes. Shorter nebulization times and 3 h nebulization in dry air did not show these effects. Nebulized surfactant reached all lung lobes, however the increase of surfactant pool size missed statistical significance. CONCLUSION: Positive effects of surfactant nebulization to spontaneously breathing preterm lambs depend on treatment duration, surfactant dose, air humidity, and surfactant distribution within the lung.

Amplification of steroid-mediated SP-B expression by physiological levels of caffeine.

Factors positively influencing surfactant homeostasis in general and surfactant protein B (SP-B) expression in particular are considered of clinical importance regarding an improvement of lung function in preterm infants. The objective of this study was to identify effects of physiological levels of caffeine on glucocorticoid-mediated SP-B expression in vitro and in vivo. Levels of SP-B and pepsinogen C were quantified by quantitative real-time RT-PCR or immunoblotting in NCI-H441 cells daily exposed to caffeine and/or dexamethasone (DEX). In vivo, SP-B expression was analyzed in bronchoalveolar lavage (BAL) of preterm sheep exposed to antenatal DEX and/or postnatal caffeine. If DEX and caffeine were continuously present, SP-B mRNA and protein levels were increased for up to 6 days after induction (P < 0.05). Additionally, caffeine enhanced SP-B mRNA expression in DEX-pretreated cells (P < 0.05). Moreover, caffeine amplified DEX-induced pepsinogen C mRNA expression (P < 0.05). After short-term treatment with caffeine in vivo, only slightly higher SP-B levels could be detected in BAL of preterm sheep following antenatal DEX, combined with an increase of arterial oxygen partial pressure (P < 0.01). Our data demonstrated that the continuous presence of caffeine in vitro is able to amplify DEX-mediated SP-B expression. In contrast, short-term improvement of lung function in vivo is likely to be independent of altered SP-B transcription and translation. An impact of caffeine on release of surfactant reservoirs from lamellar bodies could, however, quickly affect SP-B content in BAL, which has to be further investigated. Our findings indicate that caffeine is able to amplify main effects of glucocorticoids that result from changes in surfactant production, maturation, and release.

Effects of less-invasive surfactant administration on oxygenation, pulmonary surfactant distribution, and lung compliance in spontaneously breathing preterm lambs.

BACKGROUND: A new technique was proposed to administer surfactant to spontaneous breathing preterm infants by placing a thin catheter through the vocal cords. This technique was not studied with respect to oxygenation, gas exchange, surfactant distribution, and lung mechanics. We tested the technique of less-invasive surfactant administration (LISA) in a spontaneous breathing preterm lamb model. METHODS: Preterm lambs (n = 12) of 133-134 d gestational age were randomized to the following three groups: (i) continuous positive airway pressure (CPAP) only, (ii) CPAP + LISA, and (iii) intubation and mechanical ventilation with surfactant administration. Surfactant was labeled with samarium oxide. During the next 180 min, blood gas analyses were performed. Postmortem, lungs were removed and surfactant distribution was assessed, and pressure-volume curves were performed. RESULTS: Pao2 in the LISA-treated lambs was significantly higher than in the lambs that exclusively received CPAP. Moreover, Pao2 values were similar between the LISA-treated and the intubated lambs. Overall, surfactant deposition was less in the LISA lambs, with significantly less surfactant distributed to the right upper lobe. Lung compliance was better in the intubated lambs compared with the LISA-treated lambs, although this did not reach significance. CONCLUSION: LISA improved oxygenation, similar to conventional surfactant application techniques, despite lower surfactant deposition and lung compliance.

Patterns and etiology of acute and chronic lung injury: insights from experimental evidence.

Adequate pulmonary function is pivotal for preterm infants. Besides being structurally immature, the preterm lung is susceptible to injury resulting from different prenatal conditions and postnatal insults. Lung injury might result in impaired postnatal lung development, contributing to chronic lung disease of prematurity, bronchopulmonary dysplasia (BPD). This review focuses on lung injury mediated by and related to inflammatory changes in the lung. We give an overview on experimental models which have helped to elucidate mechanisms of pulmonary inflammation in prematurity. We describe experimental data linking acute and chronic chorioamnionitis with intrapulmonary inflammation, lung maturation and surfactant production in various animal models. In addition, experimental data has shown that fetal inflammatory response is modulated by the fetus himself. Experimental data has therefore helped to understand differential effects on lung function and lung maturation exerted by maternal administration of potentially anti-inflammatory substances like glucocorticosteroids (GCS). New approaches of modulation of pulmonary inflammation/injury caused by postnatal interventions during resuscitation and mechanical ventilation have been studied in animal models. Postnatal therapeutic interventions with widely used drugs like oxygen, steroids, surfactant, caffeine and vitamin A have been experimentally and mechanistically assessed regarding their effect on pulmonary inflammation and lung injury. Carefully designed experiments will help to elucidate the complex interaction between lung injury, lung inflammation, repair and altered lung development, and will help to establish a link between lung alterations originating in this early period of life and long-term adverse respiratory effects.

Optimized lung expansion ventilation modulates ventilation-induced lung injury in preterm lambs.

INTRODUCTION: Preterm infants close to viability commonly require mechanical ventilation (MV) for respiratory distress syndrome. Despite commonly used lung-sparing ventilation techniques, rapid lung expansion during MV induces lung injury, a risk factor for bronchopulmonary dysplasia. This study investigates whether ventilation with optimized lung expansion is feasible and whether it can further minimize lung injury. Therefore, optimized lung expansion ventilation (OLEV) was compared to conventional volume targeted ventilation. METHODS: Twenty preterm lambs were surgically delivered after 132 days of gestation. Nine animals were randomized to receive OLEV for 24 h, and seven received standard MV. Four unventilated animals served as controls (NV). Lungs were sampled for histological analysis at the end of the experimental period. RESULTS: Ventilation with OLEV was feasible, resulting in a significantly higher mean ventilation pressure (0.7-1.3 mbar). Temporary differences in oxygenation between OLEV and MV did not reach clinically relevant levels. Ventilation in general tended to result in higher lung injury scores compared to NV, without differences between OLEV and MV. While pro-inflammatory tumor necrosis factor-α messenger RNA (mRNA) levels increased in both ventilation groups compared to NV, only animals in the MV group showed a higher number of CD45-positive cells in the lung. In contrast, mean (standard deviations) surfactant protein-B mRNA levels were significantly lower in OLEV, 0.63 (0.38) compared to NV 1.03 (0.32) (p = .023, one-way analysis of variance). CONCLUSION: In conclusion, a small reduction in pulmonary inflammation after 24 h of support with OLEV suggests potential to reduce preterm lung injury.

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.

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.

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.

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.

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.