HIF-1α targeted deletion in myeloid cells decreases MDSC accumulation and alters microbiome in neonatal mice.

The newborn's immune system is faced with the challenge of having to learn quickly to fight off infectious agents, but tolerating the colonization of the body surfaces with commensals without reacting with an excessive inflammatory response. Myeloid-derived suppressor cells (MDSC) are innate immune cells with suppressive activity on other immune cells that regulate fetal-maternal tolerance during pregnancy and control intestinal inflammation in neonates. Until now, nothing is known about the role of MDSC in microbiome establishment. One of the transcription factors regulating MDSC homeostasis is the hypoxia-inducible factor 1α (HIF-1α). We investigated the impact of HIF-1α on MDSC accumulation and microbiome establishment during the neonatal period in a mouse model with targeted deletion of HIF-1α in myeloid cells (Hif1a loxP/loxP LysMCre+). We show that in contrast to wildtype mice, where an extensive expansion of MDSC was observed, MDSC expansion in neonatal Hif1a loxP/loxP LysMCre+ mice was dramatically reduced both systemically and locally in the intestine. This was accompanied by an altered microbiome composition and intestinal T-cell homeostasis. Our results point toward a role of MDSC in inflammation regulation in the context of microbiome establishment and thus reveal a new aspect of the biological role of MDSC during the neonatal period.

Impact of perinatal administration of probiotics on immune cell composition in neonatal mice.

BACKGROUND: Newborns and especially preterm infants are much more susceptible to infections than adults. The pathogens causing infections in newborns are often detectable in the intestinal flora of affected children even before disease onset. Therefore, it seems reasonable to prevent dysbiosis in newborns and preterm infants. An approach followed in many neonatal intensive care units (NICUs) is to prevent infections in preterm infants with probiotics however their mechanisms of action of probiotics are incompletely understood. Here, we investigated the effect of perinatal probiotic exposure on immune cells in newborn mice. METHODS: Pregnant mice were orally treated with a combination of Lactobacillus acidophilus and Bifidobacterium bifidum (Infloran®) from mid-pregnancy until the offspring were harvested. Immune cell composition in organs of the offspring were analyzed by flow cytometry. RESULTS: Perinatal probiotic exposure had profound effects on immune cell composition in the intestine, liver and lungs of newborn mice with reduction of myeloid and B cells and induction of T cells in the probiotic treated animals' organs at weaning. Furthermore, probiotic exposure had an effect on T cell development in the thymus. CONCLUSION: Our results contribute to a better understanding of the interaction of probiotics with the developing immune system. IMPACT: probiotics have profound effects on immune cell composition in intestines, livers and lungs of newborn mice. probiotics modulate T cell development in thymus of newborn mice. effects of probiotics on neonatal immune cells are particularly relevant in transition phases of the microbiome. our results contribute to a better understanding of the mechanisms of action of probiotics in newborns.

Pulse oximetry signal loss during hypoxic episodes in preterm infants receiving automated oxygen control.

The aim of this study was to analyze signal loss (SL) resulting from low signal quality of pulse oximetry-derived hemoglobin oxygen saturation (SpO2) measurements during prolonged hypoxemic episodes (pHE) in very preterm infants receiving automatic oxygen control (AOC). We did a post hoc analysis of a randomized crossover study of AOC, programmed to set FiO2 to "back-up FiO2" during SL. In 24 preterm infants (median (interquartile range)) gestational age 25.3 (24.6 to 25.6) weeks, recording time 12.7 h (12.2 to 13.6 h) per infant, we identified 76 pHEs (median duration 119 s (86 to 180 s)). In 50 (66%) pHEs, SL occurred for a median duration of 51 s (33 to 85 s) and at a median frequency of 2 (1 to 2) SL-periods per pHE. SpO2 before and after SL was similar (82% (76 to 88%) vs 82% (76 to 87%), p = 0.3)).  Conclusion: SL is common during pHE and must hence be considered in AOC-algorithm designs. Administering a "backup FiO2" (which reflects FiO2-requirements during normoxemia) during SL may prolong pHE with SL.  Trial registration: The study was registered at www. CLINICALTRIALS: gov under the registration no. NCT03785899. WHAT IS KNOWN: • Previous studies examined SpO2 signal loss (SL) during routine manual oxygen control being rare, but pronounced in lower SpO2 states. • Oxygen titration during SL is unlikely to be beneficial as SpO2 may recover to a normoxic range. WHAT IS NEW: • Periods of low signal quality of SpO2 are common during pHEs and while supported with automated oxygen control (SPOC), FiO2 is set to a back-up value reflecting FiO2 requirements during normoxemia in response to SL, although SpO2 remained below target until signal recovery. • FiO2 overshoots following pHEs were rare during AOC and occurred with a delayed onset; therefore, increased FiO2 during SL does not necessarily lead to overshoots.

Delineating morbidity patterns in preterm infants at near-term age using a data-driven approach.

BACKGROUND: Long-term survival after premature birth is significantly determined by development of morbidities, primarily affecting the cardio-respiratory or central nervous system. Existing studies are limited to pairwise morbidity associations, thereby lacking a holistic understanding of morbidity co-occurrence and respective risk profiles. METHODS: Our study, for the first time, aimed at delineating and characterizing morbidity profiles at near-term age and investigated the most prevalent morbidities in preterm infants: bronchopulmonary dysplasia (BPD), pulmonary hypertension (PH), mild cardiac defects, perinatal brain pathology and retinopathy of prematurity (ROP). For analysis, we employed two independent, prospective cohorts, comprising a total of 530 very preterm infants: AIRR ("Attention to Infants at Respiratory Risks") and NEuroSIS ("Neonatal European Study of Inhaled Steroids"). Using a data-driven strategy, we successfully characterized morbidity profiles of preterm infants in a stepwise approach and (1) quantified pairwise morbidity correlations, (2) assessed the discriminatory power of BPD (complemented by imaging-based structural and functional lung phenotyping) in relation to these morbidities, (3) investigated collective co-occurrence patterns, and (4) identified infant subgroups who share similar morbidity profiles using machine learning techniques. RESULTS: First, we showed that, in line with pathophysiologic understanding, BPD and ROP have the highest pairwise correlation, followed by BPD and PH as well as BPD and mild cardiac defects. Second, we revealed that BPD exhibits only limited capacity in discriminating morbidity occurrence, despite its prevalence and clinical indication as a driver of comorbidities. Further, we demonstrated that structural and functional lung phenotyping did not exhibit higher association with morbidity severity than BPD. Lastly, we identified patient clusters that share similar morbidity patterns using machine learning in AIRR (n=6 clusters) and NEuroSIS (n=8 clusters). CONCLUSIONS: By capturing correlations as well as more complex morbidity relations, we provided a comprehensive characterization of morbidity profiles at discharge, linked to shared disease pathophysiology. Future studies could benefit from identifying risk profiles to thereby develop personalized monitoring strategies. TRIAL REGISTRATION: AIRR: DRKS.de, DRKS00004600, 28/01/2013. NEuroSIS: ClinicalTrials.gov, NCT01035190, 18/12/2009.

Failure of an electric rocking device to improve neonatal sleep.

AIM: We wanted to investigate whether an electric rocking device (Swing2Sleep, Neumünster, Germany), sold with the claim to promote infant sleep, would increase total sleep time or reduce sleep latency once infants are put therein. METHODS: In a randomised crossover design, 20 infants (median gestational age at birth 31.7 weeks, range 25-39) were placed to sleep either first with the device rocking, then not rocking (or vice versa) for 5-7 h each. The device consisted of a hammock with three spiral springs that performed vertical swings at a rate of 100/min and an amplitude of 2.5 cm. RESULTS: There was no significant difference in %time spent asleep (83 (22-97) vs. 85% (49-96)), sleep latency (7.7 (2-45) vs. 12.3 (4-42) min), sleep fragmentation (1.3 (0.5-2.3) vs. 1.1 (0.2-5.5)) or efficiency (0.8 (0.2-1.0) vs. 0.9 (0.5-1.0)) between both conditions. CONCLUSION: At its recommended settings, the device did not achieve its intended effect in these infants.

Different probiotic strains alter human cord blood monocyte responses.

BACKGROUND: Probiotics have a protective effect on various diseases. In neonatology, they are predominantly used to prevent necrotising enterocolitis (NEC), a severe inflammatory disease of the neonatal intestine. The mechanisms by which probiotics act are diverse; little is known about their direct effect on neonatal immune cells. METHODS: In this study, we investigated the effect of probiotics on the functions of neonatal monocytes in an in vitro model using three different strains (Lactobacillus rhamnosus (LR), Lactobacillus acidophilus (LA) and Bifidobacterium bifidum (BB)) and mononuclear cells isolated from cord blood. RESULTS: We show that stimulation with LR induces proinflammatory effects in neonatal monocytes, such as increased expression of surface molecules involved in monocyte activation, increased production of pro-inflammatory and regulatory cytokines and increased production of reactive oxygen species (ROS). Similar effects were observed when monocytes were stimulated simultaneously with LPS. Stimulation with LA and BB alone or in combination also induced cytokine production in monocytes, with BB showing the least effects. CONCLUSIONS: Our results suggest that probiotics increase the defence functions of neonatal monocytes and thus possibly favourably influence the newborn's ability to fight infections. IMPACT: Probiotics induce a proinflammatory response in neonatal monocytes in vitro. This is a previously unknown mechanism of how probiotics modulate the immune response of newborns. Probiotic application to neonates may increase their ability to fight off infections.

Decreased expression of hypoxia-inducible factor 1α (HIF-1α) in cord blood monocytes under anoxia.

BACKGROUND: Infections are a major cause for morbidity and mortality in neonates; however, the underling mechanisms for increased infection susceptibility are incompletely understood. Hypoxia, which is present in inflamed tissues, has been identified as an important activation signal for innate immune cells in adults and is mainly mediated by hypoxia-inducible factor 1α (HIF-1α). Fetal tissue pO2 physiologically is low but rises immediately after birth. METHODS: In this study, the effect of low oxygen partial pressure (pO2) on HIF-1α expression and its targets phagocytosis, reactive oxygen species (ROS) production and vascular endothelial growth factor (VEGF) secretion was compared in vitro between immune cells from adult peripheral blood and cord blood using anoxia, HIF-1α stabilizer desferroxamin (DFO) and E. coli as stimuli. RESULTS: We show that anoxia-induced HIF-1α protein accumulation, phagocytosis, ROS-production and VEGF-expression were greatly diminished in cord blood compared to adult cells. E. coli led to HIF-1α gene expression in adult and cord blood immune cells; however, cord blood cells failed to accumulate HIF-1α protein and VEGF upon E. coli stimulation. CONCLUSIONS: Taken together, our results show a diminished activation of cord blood immune cells by low pO2, which might contribute to impaired reactivity in the context of infection. IMPACT: Neonatal immune cells do not accumulate HIF-1α under low oxygen partial pressure leading to decreased phagocytosis and decreased ROS production. We demonstrate a previously unknown mechanism of reduced activation of neonatal immune cells in the context of an inflammatory response. This could contribute to the increased susceptibility of newborns and preterm infants to infection.

Choline supplementation for preterm infants: metabolism of four Deuterium-labeled choline compounds.

BACKGROUND: Supply of choline is not guaranteed in current preterm infant nutrition. Choline serves in parenchyma formation by membrane phosphatidylcholine (PC), plasma transport of poly-unsaturated fatty acids (PUFA) via PC, and methylation processes via betaine. PUFA-PC concentrations are high in brain, liver and lung, and deficiency may result in developmental disorders. We compared different deuterated (D9-) choline components for kinetics of D9-choline, D9-betaine and D9-PC. METHODS: Prospective study (1/2021-12/2021) in 32 enterally fed preterm infants (28 0/7-32 0/7 weeks gestation). Patients were randomized to receive enterally a single dose of 2.7 mg/kg D9-choline-equivalent as D9-choline chloride, D9-phosphoryl-choline, D9-glycerophosphorylcholine (D9-GPC) or D9-1-palmitoyl-2-oleoyl-PC(D9-POPC), followed by blood sampling at 1 + 24 h or 12 + 60 h after administration. Plasma concentrations were analyzed by tandem mass spectrometry. Results are expressed as median (25th/75th percentile). RESULTS: At 1 h, plasma D9-choline was 1.8 (0.9/2.2) µmol/L, 1.3 (0.9/1.5) µmol/L and 1.2 (0.7/1.4) µmol/L for D9-choline chloride, D9-GPC and D9-phosphoryl-choline, respectively. D9-POPC did not result in plasma D9-choline. Plasma D9-betaine was maximal at 12 h, with lowest concentrations after D9-POPC. Maximum plasma D9-PC values at 12 h were the highest after D9-POPC (14.4 (9.1/18.9) µmol/L), compared to the other components (D9-choline chloride: 8.1 [5.6/9.9] µmol/L; D9-GPC: 8.4 (6.2/10.3) µmol/L; D9-phosphoryl-choline: 9.8 (8.6/14.5) µmol/L). Predominance of D9-PC comprising linoleic, rather than oleic acid, indicated fatty-acyl remodeling of administered D9-POPC prior to systemic delivery. CONCLUSION: D9-Choline chloride, D9-GPC and D9-phosphoryl-choline equally increased plasma D9-choline and D9-betaine. D9-POPC shifted metabolism from D9-betaine to D9-PC. Combined supplementation of GPC and (PO) PC may be best suited to optimize choline supply in preterm infants. Due to fatty acid remodeling of (PO) PC during its assimilation, PUFA co-supplementation with (PO) PC may increase PUFA-delivery to critical organs. This study was registered (22.01.2020) at the Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020502. STUDY REGISTRATION: This study was registered at the Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020502.

Different choline supplement metabolism in adults using deuterium labelling.

BACKGROUND: Choline deficiency leads to pathologies particularly of the liver, brain and lung. Adequate supply is important for preterm infants and patients with cystic fibrosis. We analysed the assimilation of four different enterally administered deuterium-labelled (D9-) choline supplements in adults. METHODS: Prospective randomised cross-over study (11/2020-1/2022) in six healthy men, receiving four single doses of 2.7 mg/kg D9-choline equivalent each in the form of D9-choline chloride, D9-phosphorylcholine, D9-alpha-glycerophosphocholine (D9-GPC) or D9-1-palmitoyl-2-oleoyl-glycero-3-phosphoryl-choline (D9-POPC), in randomised order 6 weeks apart. Plasma was obtained at baseline (t = - 0.1 h) and at 0.5 h to 7d after intake. Concentrations of D9-choline and its D9-labelled metabolites were analysed by tandem mass spectrometry. Results are shown as median and interquartile range. RESULTS: Maximum D9-choline and D9-betaine concentrations were reached latest after D9-POPC administration versus other components. D9-POPC and D9-phosphorylcholine resulted in lower D9-trimethylamine (D9-TMAO) formation. The AUCs (0-7d) of plasma D9-PC concentration showed highest values after administration of D9-POPC. D9-POPC appeared in plasma after fatty acid remodelling, predominantly as D9-1-palmitoyl-2-linoleyl-PC (D9-PLPC), confirming cleavage to 1-palmitoyl-lyso-D9-PC and re-acylation with linoleic acid as the most prominent alimentary unsaturated fatty acid. CONCLUSION: There was a delayed increase in plasma D9-choline and D9-betaine after D9-POPC administration, with no differences in AUC over time. D9-POPC resulted in a higher AUC of D9-PC and virtually absent D9-TMAO levels. D9-POPC is remodelled according to enterocytic fatty acid availability. D9-POPC seems best suited as choline supplement to increase plasma PC concentrations, with PC as a carrier of choline and targeted fatty acid supply as required by organs. This study was registered at Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020498, 22.01.2020. STUDY REGISTRATION: This study was registered at Deutsches Register Klinischer Studien (DRKS) (German Register for Clinical Studies), DRKS00020498.

Depletion of Ly6G-Expressing Neutrophilic Cells Leads to Altered Peripheral T-Cell Homeostasis and Thymic Development in Neonatal Mice.

Newborns and especially preterm infants are much more susceptible to infections than adults. Due to immature adaptive immunity, especially innate immune cells play an important role in a newborn's infection defense. Neonatal neutrophils exhibit profound differences in their functionality compared to neutrophils of adults. In particular, neonates possess a relevant population of suppressive neutrophils, which not only inhibit but also specifically modulate the function of T-cells. In this study, we investigated whether neonatal neutrophils are already involved in T-cell development in the thymus. For this purpose, we used a newly developed model of antibody-mediated immune cell depletion in which we administered a depleting antibody to pregnant and then lactating dams. Using this method, we were able to sufficiently deplete Ly6G-positive neutrophils in offspring. We demonstrated that the depletion of neutrophils in newborn mice resulted in altered peripheral T-cell homeostasis with a decreased CD4+/CD8+ T-cell ratio and decreased expression of CD62L. Neutrophil depletion even affected T-cell development in the thymus, with increased double positive thymocytes and a decreased CD4+/CD8+ single positive thymocyte ratio. Altogether, we demonstrated a previously unknown mechanism mediating neutrophils' immunomodulatory effects in newborns.

Disruptive Therapy Using a Nonsurgical Orthodontic Airway Plate for the Management of Neonatal Robin Sequence: 1-Year Follow-up.

We recently published the 3-month follow-up of 2 neonates with Robin sequence whose mandibular hypoplasia and restricted airway were successfully treated with an orthodontic airway plate (OAP) without surgical intervention. Both infants were successfully weaned off the OAP after several months of continuous use. We present the course of OAP treatment in these patients with a focus on breathing, feeding, and facial growth during their first year of life. Both infants demonstrated stable mandibular projection, resolution of obstructive sleep apnea, and normal development.

Group B streptococci infection model shows decreased regulatory capacity of cord blood cells.

BACKGROUND: Sepsis is one of the leading causes of morbidity and mortality in the neonatal period. Compared to adults, neonates are more susceptible to infections, especially to systemic infections with Group B Streptococcus (GBS). Furthermore, neonates show defects in terminating inflammation. The immunological causes for the increased susceptibility to infection and the prolonged inflammatory response are still incompletely understood. METHODS: In the present study, we aimed to investigate the reaction of cord blood mononuclear cells (MNC) to stimulation with GBS in comparison to that of MNC from adult blood with focus on the proliferative response in an in vitro infection model with heat-inactivated GBS. RESULTS: We demonstrate that after stimulation with GBS the proliferation of T cells from adult blood strongly decreased, while the proliferation of cord blood T cells remained unchanged. This effect could be traced back to a transformation of adult monocytes, but not cord blood monocytes, to a suppressive phenotype with increased expression of the co-inhibitory molecule programmed death ligand 1 (PD-L1). CONCLUSIONS: These results point towards an increased inflammatory capacity of neonatal MNC after stimulation with GBS. Targeting the prolonged inflammatory response of neonatal immune cells may be a strategy to prevent complications of neonatal infections. IMPACT: Neonatal sepsis often leads to post-inflammatory complications. Causes for sustained inflammation in neonates are incompletely understood. We show that cord blood T cells exhibited increased proliferative capacity after stimulation with group B streptococci (GBS) in comparison to adult T cells. Adult monocytes but not cord blood monocytes acquired suppressive activity and expressed increased levels of PD-L1 after GBS stimulation. Increased proliferative capacity of neonatal T cells and decreased suppressive activity of neonatal monocytes during GBS infection may contribute to prolonged inflammation and development of post-inflammatory diseases in newborns.

Validity of chronotype questionnaires in adolescents: Correlations with actigraphy.

There are only a few validated chronotype and morningness-eveningness questionnaires for adolescents. We evaluated three such questionnaires, namely Morningness-Eveningness Stability Scale improved; reduced Morningness-Eveningness Questionnaire for Children and Adolescents; and Composite Scale of Morningness in adolescents against actigraphy. Fifty-five healthy 13- to 16-year-old adolescents completed the Morningness-Eveningness Stability Scale improved, reduced Morningness-Eveningness Questionnaire for Children and Adolescents, Composite Scale of Morningness, and Pediatric Daytime Sleepiness Scale, and provided a 7-day actigraphy and sleep diary recording about their sleep-wake patterns. We examined the correlations between sleep-wake and activity parameters, and the questionnaires. The influence of age and sex on chronotype classification was studied using uni- and multivariate analyses. All three chronotype questionnaires showed good internal consistency and convergent validity. Spearman correlations reflected less daytime sleepiness, earlier sleep times, midpoints of sleep, and acrophase in morning-oriented participants. Evening-oriented participants had more sleepiness and later respective sleep-wake times. Chronotype classification differed significantly between questionnaires. The Composite Scale of Morningness classified more participants as morning types when compared with the reduced Morningness-Eveningness Questionnaire for Children and Adolescents (12 versus 7, respectively), and fewer adolescents as evening types (5 versus 9, respectively). Age and sex had no significant influence on questionnaire scores. The Morningness-Eveningness Stability Scale improved, reduced Morningness-Eveningness Questionnaire for Children and Adolescents, and Composite Scale of Morningness are valid instruments to determine circadian preference in adolescents; however, chronotype classification from the Composite Scale of Morningness and reduced Morningness-Eveningness Questionnaire for Children and Adolescents cannot be used interchangeably.

Differential metabolism of choline supplements in adult volunteers.

BACKGROUND: Adequate intake of choline is essential for growth and homeostasis, but its supply does often not meet requirements. Choline deficiency decreases phosphatidylcholine (PC) and betaine synthesis, resulting in organ pathology, especially of liver, lung, and brain. This is of particular clinical importance in preterm infants and cystic fibrosis patients. We compared four different choline supplements for their impact on plasma concentration and kinetics of choline, betaine as a methyl donor and trimethylamine oxide (TMAO) as a marker of bacterial degradation prior to absorption. METHODS: Prospective randomized cross-over study (1/2020-4/2020) in six healthy adult men. Participants received a single dose of 550 mg/d choline equivalent in the form of choline chloride, choline bitartrate, α-glycerophosphocholine (GPC), and egg-PC in randomized sequence at least 1 week apart. Blood was taken from t = - 0.1-6 h after supplement intake. Choline, betaine, TMAO, and total PC concentrations were analyzed by tandem mass spectrometry. Results are shown as medians and interquartile range. RESULTS: There was no difference in the AUC of choline plasma concentrations after intake of the different supplements. Individual plasma kinetics of choline and betaine differed and concentrations peaked latest for PC (at ≈3 h). All supplements similarly increased plasma betaine. All water-soluble supplements rapidly increased TMAO, whereas egg-PC did not. CONCLUSION: All supplements tested rapidly increased choline and betaine levels to a similar extent, with egg-PC showing the latest peak. Assuming that TMAO may have undesirable effects, egg-PC might be best suited for choline supplementation in adults. STUDY REGISTRATION: This study was registered at "Deutsches Register Klinischer Studien" (DRKS) (German Register for Clinical Studies), 17.01.2020, DRKS00020454.

Neurocognitive development in isolated Robin sequence treated with the Tuebingen palatal plate.

OBJECTIVES: We aimed to determine the neurocognitive development of cleft palate patients with and without Robin sequence (RS). MATERIALS AND METHODS: Children with isolated RS with cleft palate and children with cleft palate only (CPO) were contacted at the age of 5-6 years. All RS children had undergone initial polygraphic sleep study (PG) with a mixed-obstructive apnea index (MOAI) of ≥ 3/h and were consequently treated with the Tuebingen palatal plate. A standardized clinical examination as well as a neuropediatric and neuropsychological examination included the Wechsler Pre-school and Primary Scale of Intelligence (WPPSI-III), Kaufman Assessment Battery for Children (K-ABC), and an assessment of developmental milestones. RESULTS: In total, 44 children (22RS, 22CPO) were included. RS children were younger at study (70.5 ± 7.3 and 75.2 ± 7.5 months; P = .035). Both groups achieved the evaluated milestones within the normed time frame. WPPSI-III and K-ABC results showed no group differences. Mean values for Verbal IQ (101.8 ± 11.1 vs. 97.1 ± 15.7), Performance IQ (102.9 ± 12.1 vs. 99.6 ± 14.5), Processing Speed Quotient (98.9 ± 15.6 vs. 94.5 ± 15.7), Full-Scale IQ (103.2 ± 12.1 vs. 98.4 ± 15.3), and Sequential Processing Scale (102.1 ± 13.1 vs. 94.2 ± 17.3) were within the reference range (IQ 85-115) for RS and CPO children, respectively, indicating average performance of both groups. CONCLUSION: No neurocognitive, physical, or mental impairments were detected suggesting that RS children having upper airway obstruction (UAO) treated early and effectively may use their potential for an age-appropriate neurocognitive development. CLINICAL RELEVANCE: Tuebingen palatal plate treatment successfully releases UAO. Thus, isolated RS does not necessarily result in developmental delay or an impaired neurocognitive outcome. TRIAL REGISTRATION: Deutsches Register Klinischer Studien, DRKS00006831, https://www.drks.de/drks_web/.

Long-Term Effects of Inhaled Budesonide for Bronchopulmonary Dysplasia.

BACKGROUND: The long-term effects on neurodevelopment of the use of inhaled glucocorticoids in extremely preterm infants for the prevention or treatment of bronchopulmonary dysplasia are uncertain. METHODS: We randomly assigned 863 infants (gestational age, 23 weeks 0 days to 27 weeks 6 days) to receive early (within 24 hours after birth) inhaled budesonide or placebo. The prespecified secondary long-term outcome was neurodevelopmental disability among survivors, defined as a composite of cerebral palsy, cognitive delay (a Mental Development Index score of <85 [1 SD below the mean of 100] on the Bayley Scales of Infant Development, Second Edition, with higher scores on the scale indicating better performance), deafness, or blindness at a corrected age of 18 to 22 months. RESULTS: Adequate data on the prespecified composite long-term outcome were available for 629 infants. Of these infants, 148 (48.1%) of 308 infants assigned to budesonide had neurodevelopmental disability, as compared with 165 (51.4%) of 321 infants assigned to placebo (relative risk, adjusted for gestational age, 0.93; 95% confidence interval [CI], 0.80 to 1.09; P=0.40). There was no significant difference in any of the individual components of the prespecified outcome. There were more deaths in the budesonide group than in the placebo group (82 [19.9%] of 413 infants vs. 58 [14.5%] of 400 infants for whom vital status was available; relative risk, 1.37; 95% CI, 1.01 to 1.86; P=0.04). CONCLUSIONS: Among surviving extremely preterm infants, the rate of neurodevelopmental disability at 2 years did not differ significantly between infants who received early inhaled budesonide for the prevention of bronchopulmonary dysplasia and those who received placebo, but the mortality rate was higher among those who received budesonide. (Funded by the European Union and Chiesi Farmaceutici; ClinicalTrials.gov number, NCT01035190 .).

Extracellular vesicles released by myeloid-derived suppressor cells from pregnant women modulate adaptive immune responses.

Immunological pregnancy complications are a main challenge in reproductive medicine. Mechanisms regulating the adaptation of the maternal immune system to pregnancy are incompletely understood and therapeutic options limited. Myeloid derived suppressor cells (MDSC) are immune-modulatory cells expanding during healthy pregnancy and seem to play a crucial role for maternal-fetal tolerance. Recent studies showed that exosomes produced by MDSC have immune-modulatory effects corresponding to their parental cells under different pathological conditions. Here, we investigated immunological effects of exosomes of GR-MDSC during pregnancy. Isolated GR-MDSC exosomes from peripheral blood of pregnant women were tested for functionality in different in vitro assays. We show that GR-MDSC exosomes exhibited profound immune-modulatory effects such as suppression of T-cell proliferation, T helper 2 (Th2)-cell polarization, induction of regulatory T-cells and inhibition of lymphocyte cytotoxicity. Our results confirm that MDSC-derived exosomes functionally correspond to their parental cells and identify them as an interesting therapeutic target for immunological pregnancy complications.

Modulatory activity of adenosine on the immune response in cord and adult blood.

BACKGROUND: Neonatal sepsis is a leading cause of neonatal morbidity and mortality, associated with immunosuppression. Myeloid-derived suppressor cells (MDSCs) are cells with immunosuppressive activity, present in high amounts in cord blood. Mechanisms regulating MDSC expansion are incompletely understood. Adenosine is a metabolite with immunoregulatory effects that are elevated in cord blood. METHODS: Impact of adenosine on peripheral and cord blood mononuclear cells (PBMCs and CBMCs) was analysed by quantification of ectonucleotidases and adenosine receptor expression, MDSC induction from PBMCs and CBMCs, their suppressive capacity on T cell proliferation and effector enzyme expression by flow cytometry. RESULTS: Cord blood monocytes mainly expressed CD39, while cord blood T cells expressed CD73. Adenosine-induced MDSCs from PBMCs induced indoleamine-2,3-dioxygenase (IDO) expression and enhanced arginase I expression in monocytes. Concerted action of IDO and ArgI led to effective inhibition of T cell proliferation. In addition, adenosine upregulated inhibitory A3 receptors on monocytes. CONCLUSION: Adenosine acts by inducing MDSCs and upregulating inhibitory A3 receptors, probably as a mode of autoregulation. Thus, adenosine contributes to immunosuppressive status and may be a target for immunomodulation during pre- and postnatal development. IMPACT: Immune effector cells, that is, monocytes, T cells and MDSCs from cord blood express ectonucleotidases CD39 and CD73 and may thus serve as a source for adenosine as an immunomodulatory metabolite. Adenosine mediates its immunomodulatory properties in cord blood by inducing MDSCs, and by modulating the inhibitory adenosine A3 receptor on monocytes. Adenosine upregulates expression of IDO in MDSCs and monocytes potentially contributing to their suppressive activity.

Lipid enemas for meconium evacuation in preterm infants - a retrospective cohort study.

BACKGROUND: Enemas are used in preterm infants to promote meconium evacuation, but frequent high-volume enemas might contribute to focal intestinal perforation (FIP). To replace a regime consisting of frequent enemas of varying volume and composition, we implemented a once-daily, low-volume lipid enema (LE) regimen. We investigated its impact on meconium evacuation, enteral nutrition, and gastrointestinal complications in preterm infants. METHODS: We performed a single-center retrospective study comparing cohorts of preterm infants < 28 weeks gestation or < 32 weeks, but with birth weight < 10th percentile, before and after implementing LE. Outcomes were rates of FIP, necrotizing enterocolitis (NEC), and sepsis. We assessed stooling patterns, early enteral and parenteral nutrition. We used descriptive statistics for group comparisons and logistic regression to identify associations between LE and gastrointestinal complications and to adjust for group imbalances and potential confounders. Exclusion criteria were gastrointestinal malformations or pre-determined palliative care. RESULTS: Data from 399 infants were analyzed, 203 before vs. 190 after implementing LE; in the latter period, 55 protocol deviations occurred where infants received no enema, resulting in 3 groups with either variable enemas, LE or no enema use. Rates of FIP and sepsis were 11.9% vs. 6.4% vs. 0.0% and 18.4% vs. 13.5% vs. 14.0%, respectively. NEC rates were 3.0% vs. 7.8% vs. 3.5%. Adjusted for confounders, LE had no effect on FIP risk (aOR 1.1; 95%CI 0.5-2.8; p = 0.80), but was associated with an increased risk of NEC (aOR 2.9; 95%CI 1.0-8.6; p = 0.048). While fewer enemas were applied in the LE group resulting in a prolonged meconium passage, no changes in early enteral and parenteral nutrition were observed. We identified indomethacin administration and formula feeding as additional risk factors for FIP and NEC, respectively (aOR 3.5; 95%CI 1.5-8.3; p < 0.01 and aOR 3.4; 95%CI 1.2-9.3; p = 0.02). CONCLUSION: Implementing LE had no clinically significant impact on meconium evacuation, early enteral or parenteral nutrition. FIP and sepsis rates remained unaffected. Other changes in clinical practice, like a reduced use of indomethacin, possibly affected FIP rates in our cohorts. The association between LE and NEC found here argues against further adoption of this practice. TRIAL REGISTRATION: Registered at the German Register of Clinical Trials (no. DRKS00024021 ; Feb 022021).

Comparison of nostril sizes of newborn infants with outer diameter of endotracheal tubes.

BACKGROUND: Recommendations for endotracheal tube (ETT) size usually refer to the inner diameter (ID). Outer diameters (OD), however, vary greatly between manufacturers, which in some brands might cause difficulties in passing the ETT through the nostrils if choosing the nasal route for intubation. Even though the nostrils are dilatable by an ETT, it might be difficult to pass an ETT through the posterior naris (narrowest point of the nasal passage), if the OD is bigger than the nostrils. Therefore, nostril size may provide some guidance for the appropriate ETT size preventing unsuccessful intubation attempts. This study therefore compares nostril sizes of newborn infants with ODs of ETTs from several manufacturers. METHODS: This is a subgroup analysis of a prospective observational study, performed in a single tertiary perinatal centre in Germany. The diameter of the nostril of infants born between 34 and 41 weeks´ gestation was measured in 3D images using 3dMDvultus software and compared to the OD of ETT from five different manufacturers. RESULTS: Comparisons of nostril sizes with ODs of different ETTs were made for 99 infants with a mean (SD) birthweight of 3058g (559) [range: 1850-4100g]. Mean (SD) nostril size was 5.3mm (0.6). The OD of the 3.5mm ETT of different manufacturers ranged from 4.8-5.3mm and was thus larger than the nostril size of 20-46% of late preterm or term infants. Some OD of a 3.0mm ETT were even bigger than the OD of a 3.5mm ETT (e.g. the 3.0mm ETT from Rüsch® has an OD of 5.0mm while the 3.5mm ETT from Portex® has an OD of 4.8mm). CONCLUSIONS: Clinicians should be aware of the OD of ETTs to reduce unsuccessful intubation attempts caused by ETT sizes not fitting the nasal cavity. Generated data may help to adapt recommendations in future. TRIAL REGISTRATION: Subgroup analysis of the "Fitting of Commonly Available Face Masks for Late Preterm and Term Infants (CAFF)"-study: NCT03369028, www.ClinicalTrials.gov , December 11, 2017.