Early postnatal high-dose fat-soluble enteral vitamin A supplementation for moderate or severe bronchopulmonary dysplasia or death in extremely low birthweight infants (NeoVitaA): a multicentre, randomised, parallel-group, double-blind, placebo-controlled, investigator-initiated phase 3 trial.

BACKGROUND: Vitamin A plays a key role in lung development, but there is no consensus regarding the optimal vitamin A dose and administration route in extremely low birthweight (ELBW) infants. We aimed to assess whether early postnatal additional high-dose fat-soluble enteral vitamin A supplementation versus placebo would lower the rate of moderate or severe bronchopulmonary dysplasia or death in ELBW infants receiving recommended basic enteral vitamin A supplementation. METHODS: This prospective, multicentre, randomised, parallel-group, double-blind, placebo-controlled, investigator-initiated phase 3 trial conducted at 29 neonatal intensive care units in Austria and Germany assessed early high-dose enteral vitamin A supplementation (5000 international units [IU]/kg per day) or placebo (peanut oil) for 28 days in ELBW infants. Eligible infants had a birthweight of more than 400 g and less than 1000 g; gestational age at birth of 32+0 weeks postmenstrual age or younger; and the need for mechanical ventilation, non-invasive respiratory support, or supplemental oxygen within the first 72 h of postnatal age after admission to the neonatal intensive care unit. Participants were randomly assigned by block randomisation with variable block sizes (two and four). All participants received basic vitamin A supplementation (1000 IU/kg per day). The composite primary endpoint was moderate or severe bronchopulmonary dysplasia or death at 36 weeks postmenstrual age, analysed in the intention-to-treat population. This trial was registered with EudraCT, 2013-001998-24. FINDINGS: Between March 2, 2015, and Feb 27, 2022, 3066 infants were screened for eligibility at the participating centres. 915 infants were included and randomly assigned to the high-dose vitamin A group (n=449) or the control group (n=466). Mean gestational age was 26·5 weeks (SD 2·0) and mean birthweight was 765 g (162). Moderate or severe bronchopulmonary dysplasia or death occurred in 171 (38%) of 449 infants in the high-dose vitamin A group versus 178 (38%) of 466 infants in the control group (adjusted odds ratio 0·99, 95% CI 0·73-1·55). The number of participants with at least one adverse event was similar between groups (256 [57%] of 449 in the high-dose vitamin A group and 281 [60%] of 466 in the control group). Serum retinol concentrations at baseline, at the end of intervention, and at 36 weeks postmenstrual age were similar in the two groups. INTERPRETATION: Early postnatal high-dose fat-soluble enteral vitamin A supplementation in ELBW infants was safe, but did not change the rate of moderate or severe bronchopulmonary dysplasia or death and did not substantially increase serum retinol concentrations. FUNDING: Deutsche Forschungsgemeinschaft and European Clinical Research Infrastructures Network (ECRIN).

Diverging effects of premature birth and bronchopulmonary dysplasia on exercise capacity and physical activity - a case control study.

BACKGROUND: Extreme prematurity has been associated with exercise intolerance and reduced physical activity. We hypothesized that children with bronchopulmonary dysplasia (BPD) would be especially affected based on long-term lung function impairments. Therefore, the objective of this study was to compare exercise capacity and habitual physical activity between children born very and extremely preterm with and without BPD and term-born children. METHODS: Twenty-two school-aged children (aged 8 to 12 years) born with a gestational age < 32 weeks and a birthweight < 1500 g (9 with moderate or severe BPD (=BPD), 13 without BPD (=No-BPD)) and 15 healthy term-born children (=CONTROL) were included in the study. Physical activity was measured by accelerometry, lung function by spirometry and exercise capacity by an incremental cardiopulmonary exercise test. RESULTS: Peak oxygen uptake was reduced in the BPD-group (83 ± 11%predicted) compared to the No-BPD group (91 ± 8%predicted) and the CONTROL group (94 ± 9%predicted). In a general linear model, variance of peak oxygen uptake was significantly explained by BPD status and height but not by prematurity (p < 0.001). Compared to CONTROL, all children born preterm spent significantly more time in sedentary behaviour (BPD 478 ± 50 min, No-BPD 450 ± 52 min, CONTROL 398 ± 56 min, p < 0.05) and less time in moderate-to-vigorous-physical activity (BPD 13 ± 8 min, No-BPD 16 ± 8 min, CONTROL 33 ± 16 min, p < 0.001). Prematurity but not BPD contributed significantly to explained variance in a general linear model of sedentary behaviour and likewise moderate-to-vigorous-physical activity (p < 0.05 and p < 0.001 respectively). CONCLUSION: In our cohort, BPD but not prematurity was associated with a reduced exercise capacity at school-age. However, prematurity regardless of BPD was related to less engagement in physical activity and more time spent in sedentary behaviour. Thus, our findings suggest diverging effects of prematurity and BPD on exercise capacity and physical activity.

Secondary haemophagocytic lymphohistiocytosis triggered by postnatally acquired cytomegalovirus infection in a late preterm infant.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory condition with impairment of cytotoxic T-cells and natural killer cells. Causes in infants are mostly hereditary immune defects as well as various infectious triggering factors, amongst these cytomegalovirus (CMV). Vertical CMV transmission may occur in utero, during birth, and by breast feeding. Usually, a CMV infection transmitted via breast milk is symptomatic only in very immature preterm infants. We report on a late preterm infant born after 35 + 5 weeks of gestation with a birth weight of 1840 g, being admitted to our intensive care unit at the age of 9 weeks with acute enteritis and severe dehydration. After a prolonged recovery, the infant developed a sepsis-like condition with hyperpyrexia, hepatosplenomegaly, and pancytopenia. Combination with high ferritin levels (2809 µg/l), hypertriglyceridaemia (481 mg/dl), elevated soluble IL-2 receptor (sCD25, 9120 U/ml), and reduced perforin expression allowed diagnosis of HLH, caused by an acute CMV infection. Since connatal CMV infection had been ruled out earlier, we report the rare case of secondary HLH triggered by a postnatally acquired symptomatic CMV infection in an immunocompetent infant, most likely transmitted via breast milk. The infant was successfully treated with ganciclovir without need for immunosuppressive therapy.

Activating Injury-Responsive Genes with Hypoxia Enhances Axon Regeneration through Neuronal HIF-1α.

Injured peripheral neurons successfully activate a proregenerative transcriptional program to enable axon regeneration and functional recovery. How transcriptional regulators coordinate the expression of such program remains unclear. Here we show that hypoxia-inducible factor 1α (HIF-1α) controls multiple injury-induced genes in sensory neurons and contribute to the preconditioning lesion effect. Knockdown of HIF-1α in vitro or conditional knock out in vivo impairs sensory axon regeneration. The HIF-1α target gene Vascular Endothelial Growth Factor A (VEGFA) is expressed in injured neurons and contributes to stimulate axon regeneration. Induction of HIF-1α using hypoxia enhances axon regeneration in vitro and in vivo in sensory neurons. Hypoxia also stimulates motor neuron regeneration and accelerates neuromuscular junction re-innervation. This study demonstrates that HIF-1α represents a critical transcriptional regulator in regenerating neurons and suggests hypoxia as a tool to stimulate axon regeneration.

Chorioamnionitis is essential in the evolution of bronchopulmonary dysplasia--the case in favour.

Bronchopulmonary dysplasia (BPD) is a major sequel of extremely premature birth. Multiple ante- and postnatal factors act in concert to injure the immature lung in the pathogenesis of the disease. Among them, chorioamnionitis--according to current evidence--plays a pivotal role. Pulmonary inflammatory processes seen in animal models of chorioamnionitis resemble those seen in premature infants who developed BPD. Chorioamnionitis can doubtlessly induce extremely preterm birth, thus contributing to a gestation-dependent risk of BPD. A gestation-independent association of chorioamnionitis with an increased risk of developing BPD has been demonstrated by a recent systematic review of clinical observational studies. Antenatal inflammation with signs of a systemic fetal response reduces the response to exogenous surfactant in infants with respiratory distress syndrome, leading to a longer need for mechanical ventilation. Moreover, chorioamnionitis increases the risk of early onset sepsis. Both mechanical ventilation and sepsis are, however, major postnatal risk factors for BPD.

Soluble adenylyl cyclase activity is necessary for retinal ganglion cell survival and axon growth.

cAMP is a critical second messenger mediating activity-dependent neuronal survival and neurite growth. We investigated the expression and function of the soluble adenylyl cyclase (sAC, ADCY10) in CNS retinal ganglion cells (RGCs). We found sAC protein expressed in multiple RGC compartments including the nucleus, cytoplasm and axons. sAC activation increased cAMP above the level seen with transmembrane adenylate cyclase (tmAC) activation. Electrical activity and bicarbonate, both physiologic sAC activators, significantly increased survival and axon growth, whereas pharmacologic or siRNA-mediated sAC inhibition dramatically decreased RGC survival and axon growth in vitro, and survival in vivo. Conversely, RGC survival and axon growth were unaltered in RGCs from AC1/AC8 double knock-out mice or after specifically inhibiting tmACs. These data identify a novel sAC-mediated cAMP signaling pathway regulating RGC survival and axon growth, and suggest new neuroprotective or regenerative strategies based on sAC modulation.

Chorioamnionitis--the good or the evil for neonatal outcome?

Chorioamnionitis represents a major risk factor for preterm birth and contributes to prematurity-associated morbidity and mortality. Comparison of studies addressing neonatal outcome after exposure to either histological or clinical chorioamnionitis is hampered by the great heterogeneity regarding study cohorts and disease definitions which were applied. Moreover, the impact of exposure to inflammation in utero on neonatal outcome has become less evident with major advances in perinatal and neonatal care. Histologic chorioamnionitis evidently is associated with a reduction of incidence and severity of respiratory distress syndrome. Short-term maturational effects on the lungs of ventilated extremely premature infants are, however, accompanied by a greater susceptibility of the lung, eventually contributing to an increased risk of bronchopulmonary dysplasia. Chorioamnionitis has been shown associated with increased rate of early-onset sepsis but, according to recent data, histological chorioamnionitis might be protective against late-onset sepsis. Inconsistent data exist concerning the true role of chorioamnionitis in the development of brain lesions such as cystic periventricular leukomalacia, diffuse white matter disease, and intraventricular hemorrhage. However, an association with the development of cerebral palsy has been reported.

Myocardial response in preterm fetal sheep exposed to systemic endotoxinaemia.

Exposure of the fetus to antenatal inflammation can occur from chorioamnionitis, which may progress to a fetal inflammatory response syndrome (FIRS) and to fetal sepsis. We tested whether the fetal myocardium responded to systemic Gram-negative endotoxinaemia. We hypothesized that the myocardium would respond to inflammation by changes in hypoxia-inducible factor-α (HIF-1α), inducible NO-synthase (iNOS), Toll-like receptors 2 and 4 (TLR2 and TLR4), IL-6, and phosphorylated signal transducer and activator of transcription-3 (pSTAT3). To model systemic endotoxinaemia, fetal sheep were exposed to Gram-negative endotoxin or saline i.v. 3 d before preterm delivery at 113 d of gestation (term = 147 d). All endotoxin-exposed animals developed cardiac dysfunction within these 72 h. Cardiac mRNA and protein levels of HIF-1α and TLR2 and TLR4 mRNA increased, whereas STAT3 phosphorylation decreased significantly. IL-6 and iNOS mRNA remained unchanged. Fetal systemic endotoxinaemia induced myocardial inflammation by activating TLR2 and 4. The following cardiac dysfunction seems not to be mediated via cardiac iNOS.

Airway angiopoietin-2 in ventilated very preterm infants: association with prenatal factors and neonatal outcome.

OBJECTIVE: Pulmonary angiogenesis is a prerequisite for lung development. Angiopoietin-2 (Ang2) destabilizes endothelial cells through its endothelial receptor TIE-2, enabling vascular sprouting. Ang1 stabilizes new blood vessels. Soluble TIE-2 (sTIE-2) modulates these effects. We hypothesized that histological funisitis is associated with alterations of Ang2 in airways and of the systemic angiopoietin-TIE-2 homeostasis in very low birth weight (VLBW) infants, contributing to pulmonary morbidity and mortality. METHODS: We measured Ang2 in tracheobronchial aspirate fluid (TAF) of 42 VLBW <30 weeks of gestation from day 1 through 15 and Ang1, Ang2, and sTIE-2 in umbilical cord serum of 28 infants by enzyme-linked immunosorbent assay. Histological examination distinguished three groups: funisitis, chorioamnionitis, and controls. RESULTS: Funisitis was associated with lower Ang2 values in TAF but not with changes of Ang1, Ang2, and sTIE-2 in umbilical cord serum. Infants who developed bronchopulmonary dysplasia (BPD) or died had a persistently decreased ratio of previously measured Ang1 to Ang2 in TAF on days 1-5 and increased cord serum concentrations of sTIE-2. Moderate BPD/death was associated with an increase of Ang2 in TAF on day 10 and decreased Ang1/Ang2 ratio from day 3-15. Small for gestational age (SGA) infants had increased Ang2 in TAF on day 1-7 and a lower Ang1/Ang2 ratio on days 5-7. CONCLUSIONS: The predominance of Ang2 in airway fluid of infants with BPD/death and SGA infants suggests a link between disrupted placental and fetal pulmonary angiogenesis. Histological funisitis with reduced Ang2 in TAF was of minor relevance for outcome in our cohort.

Chorioamnionitis: important risk factor or innocent bystander for neonatal outcome?

Chorioamnionitis as a major risk factor for spontaneous preterm birth, especially at earlier gestational ages, contributes to prematurity-associated mortality and morbidity. A gestation-independent effect of chorioamnionitis on neonatal outcome is much more difficult to assess. The influence of chorioamnionitis on neonatal outcome has become less evident with advances in neonatal care. A short-term beneficial effect of histological, but not clinical chorioamnionitis on incidence and severity of respiratory distress syndrome in preterm infants is evident. This maturational effect is accompanied by a susceptibility of the lung for further postnatal injury, which predisposes for bronchopulmonary dysplasia. Chorioamnionitis is associated with cystic periventricular leukomalacia, intraventricular hemorrhage and cerebral palsy in preterm infants, but its association with noncystic white matter disease is not clear yet. Prenatal inflammation/infection has been shown a risk factor for neonatal sepsis. A single course of antenatal steroids can be regarded safe in clinical as well as histological chorioamnionitis.

Gene expression of axon growth promoting factors in the deer antler.

The annual regeneration cycle of deer (Cervidae, Artiodactyla) antlers represents a unique model of epimorphic regeneration and rapid growth in adult mammals. Regenerating antlers are innervated by trigeminal sensory axons growing through the velvet, the modified form of skin that envelopes the antler, at elongation velocities that reach one centimetre per day in the common deer (Cervus elaphus). Several axon growth promoters like NT-3, NGF or IGF-1 have been described in the antler. To increase the knowledge on the axon growth environment, we have combined different gene-expression techniques to identify and characterize the expression of promoting molecules not previously described in the antler velvet. Cross-species microarray analyses of deer samples on human arrays allowed us to build up a list of 90 extracellular or membrane molecules involved in axon growth that were potentially being expressed in the antler. Fifteen of these genes were analysed using PCR and sequencing techniques to confirm their expression in the velvet and to compare it with the expression in other antler and skin samples. Expression of 8 axon growth promoters was confirmed in the velvet, 5 of them not previously described in the antler. In conclusion, our work shows that antler velvet provides growing axons with a variety of promoters of axon growth, sharing many of them with deer's normal and pedicle skin.

Glucocorticoids potentiate IL-6-induced SP-B expression in H441 cells by enhancing the JAK-STAT signaling pathway.

The respiratory distress syndrome (RDS) contributes to perinatal morbidity and mortality associated with preterm birth. Surfactant protein B (SP-B) is decreased in RDS. Both maternal antenatal steroid administration and chorioamnionitis reduce the incidence and severity of RDS. An important mediator in chorioamnionitis is IL-6 using the JAK-STAT signaling pathway for signal transduction. We hypothesized that the steroids, betamethasone (BTM) and dexamethasone (DXM), and IL-6 had synergistic effects on SP-B gene expression and STAT3 phosphorylation in H441 cells. DXM and BTM increased SP-B mRNA levels by 16.5 (13.3)-fold and IL-6 alone by 2.3-fold. After 48-h exposure of cells to DXM or BTM, IL-6 caused a significantly greater increase in SP-B mRNA levels (28.1-fold) than IL-6 or glucocorticoids alone. Whereas IL-6 stimulated tyrosine phosphorylation of STAT3 in a time- and dose-dependent way, DXM and BTM had no effect on STAT3 phosphorylation. Both DXM and BTM could potentiate IL-6-induced phosphorylation of STAT3. The synergism of glucocorticoids and IL-6 on SP-B gene expression and the effect of glucocorticoids on IL-6-induced STAT3 phosphorylation could be blocked by a JAK inhibitor. Expression level analysis showed that glucocorticoids increased the expression of the IL-6-binding α-subunit receptor (IL-6R) on mRNA and protein level. Our findings could represent an example of a pulmonary regulation system in which one role of glucocorticoids is to increase the effect of a cytokine by upregulation of its receptor. The described in vitro interaction of IL-6 and glucocorticoids could help explain the clinical observation that prenatal inflammation in preterm babies with antenatal steroid administration can attenuate severity of RDS.

Clara cell secretory protein in tracheobronchial aspirates and umbilical cord serum of extremely premature infants with systemic inflammation.

BACKGROUND: A systemic fetal inflammatory response, reflected by chorioamnionitis with funisitis, is a risk factor for bronchopulmonary dysplasia. Clara cell secretory protein (CC10), a product of pulmonary Clara cells, has anti-inflammatory properties. Local down-regulation of CC10 has been associated with inflammatory lung disease. Increased serum levels of CC10 can indicate injury to alveolar-capillary integrity. OBJECTIVE: We hypothesized that extremely premature infants with a systemic fetal inflammatory response would have decreased concentrations of CC10 in tracheobronchial aspirates and that CC10 concentrations in umbilical cord serum of these infants would be increased, reflecting alveolar epithelial damage. METHODS: We measured CC10 concentrations in tracheobronchial aspirates of 42 ventilated extremely premature infants during their first week of life and in umbilical cord serum of 24 of them by ELISA. Standardized histological examination of the placenta, membranes and umbilical cord was used to identify infants with funisitis. RESULTS: Seventeen infants with funisitis had lower CC10 concentrations in tracheobronchial aspirates on days 1 (p < 0.01) and 3 (p < 0.05) than the remaining 25. Exogenous surfactant treatment was associated with higher CC10 concentrations on day 1 (p < 0.05). Initial leukocyte count correlated inversely with CC10 in tracheobronchial aspirates on days 1-5. Umbilical cord serum concentrations of CC10 did not differ between the infants with funisitis and the controls. CONCLUSIONS: Reduced anti-inflammatory CC10 concentrations in airways of extremely premature infants with a fetal inflammatory response might make their lungs susceptible for further postnatal injuries. Umbilical cord serum CC10 is not an indicator for a fetal systemic inflammatory reaction.

Airway concentrations of angiopoietin-1 and endostatin in ventilated extremely premature infants are decreased after funisitis and unbalanced with bronchopulmonary dysplasia/death.

A systemic inflammatory response of the fetus, reflected by histologic funisitis, is a risk factor for bronchopulmonary dysplasia (BPD). Impaired pulmonary angiogenesis accompanied by simplification and rarification of alveoli is a histologic hallmark of BPD. Angiopoietin-1 mediates vascular development, maturation, and stabilization. Endostatin mainly acts as an angiostatic factor. We hypothesized that funisitis was associated with changes of endostatin and angiopoietin-1 concentrations in the airways and that an imbalance between the factors might be associated with BPD or death. We measured concentrations of angiopoietin-1 and endostatin by enzyme-linked immunosorbent assay in tracheobronchial aspirate fluid samples of 42 ventilated preterm infants during postnatal days 1 through 15. The secretory component for IgA served as reference protein. A standardized histologic examination was used to distinguish three groups: chorioamnionitis, funisitis, and controls without inflammation. Concentrations of the mediators steadily decreased. Funisitis was associated with lower concentrations of both proteins, which might impair their physiologic activities in pulmonary angiogenesis. An increase of the ratio angiopoietin-1/endostatin until day 7 of life indicated a shift of the mediators potentially favoring angiogenesis. However, infants, who developed BPD or died, had a decreased ratio on days 1, 3, and 15, suggesting an imbalance toward inhibition of pulmonary angiogenesis.

Systemic fetal inflammation and reduced concentrations of macrophage migration inhibitory factor in tracheobronchial aspirate fluid of extremely premature infants.

OBJECTIVE: Macrophage migration inhibitory factor is a proinflammatory mediator of innate immunity, enhances cell growth, and plays a role in preterm delivery. We speculated that funisitis, reflecting fetal systemic inflammation, would be associated with higher concentrations of macrophage migration inhibitory factor in airways of extremely premature infants. STUDY DESIGN: We measured macrophage migration inhibitory factor by enzyme linked immunosorbent assay in tracheobronchial aspirate fluid of 35 ventilated infants less than 30 weeks' gestational age, throughout the first week of life. Three groups were distinguished histologically: chorioamnionitis, funisitis, and control. RESULTS: Unexpectedly, funisitis was associated with significantly decreased macrophage migration inhibitory factor in tracheobronchial aspirate fluid on day 1 (P < .01) and levels remained lower than in the chorioamnionitis group thereafter. For the 35 patients in total, macrophage migration inhibitory factor steadily declined. CONCLUSION: Decreased macrophage migration inhibitory factor concentrations in airways of extremely premature infants with systemic fetal inflammation early in life might predispose them to pulmonary infection and interfere with maturation of the lung, contributing to adverse pulmonary outcome.

Prevention and therapy of bronchopulmonary dysplasia - evidence and clinical practice.

The knowledge on the pathogenetic mechanisms of bronchopulmonary dysplasia (BPD) has increased considerably over recent years. However, the incidence of the disease has not substantially been changed by our therapeutic approaches. This review summarizes the existing evidence for a number of respiratory and medical strategies to prevent or ameliorate the disease and gives recommendations for clinical practice. Oxygen plays an important pathogenetic and therapeutic role for BPD. Targeting infants at lower oxygen saturation levels than traditionally used seems to confer major advantages. There is no sufficient evidence for a routine use of respiratory strategies like permissive hypercapnia or inhaled nitric oxide to prevent BPD. Diuretics can ameliorate lung function transiently. High intramuscular doses of vitamin A can reduce the risk of BPD. Early or prophylactic surfactant might also be advantageous. Postnatal corticosteroids are effective but, due to their severe side effects, should be restricted to the severest cases. Alpha1-proteinase inhibitor and superoxide dismutase have no proven benefits for BPD. The role of erythromycin has not been completely elucidated yet. Innovative strategies like Clara Cell 10 kD protein still have to be assessed in future trials.

Management of infants with bronchopulmonary dysplasia in Germany.

Although official guidelines for diagnosis and treatment of bronchopulmonary dysplasia (BPD) exist in Germany the practice in tertiary care neonatology centres differs considerably. There is no consensus about the appropriate level of oxygen saturation for infants at risk for BPD or infants with established BPD. Targeting oxygen saturation just below 90% in the first weeks and in the lower nineties thereafter seems to be a reasonable approach. Systemic corticosteroids must be used very restrictively because of adverse short- and long-term outcomes. Diuretics, inhaled corticosteroids, and bronchodilators may be used based on a stringent assessment of the individual response; their routine use cannot be recommended. Domiciliary oxygen is a therapy rarely prescribed in Germany although, if carefully planned and organised, it is safe and effective. Infants with home oxygen need a close follow-up by neonatologists and other specialists. Routine vaccination is recommended from the postnatal age of 3 months onwards.