Neonatal lymphocyte subpopulations analysis and maternal preterm premature rupture of membranes: a pilot study

Abstract Objectives Preterm premature rupture of membranes (pPROM) causes preterm delivery, and increases maternal T-cell response against the fetus. Fetal inflammatory response prompts maturation of the newborn's immunocompetent cells, and could be associated with unfavorable neonatal outcome. The aims were (1) to examine the effects of pPROM on the newborn's and mother's immune system and (2) to assess the predictive value of immune system changes in neonatal morbidity. Methods Mother-newborn pairs (18 mothers and 23 newborns) who experienced pPROM and controls (11 mothers and 14 newborns), were enrolled. Maternal and neonatal whole blood samples underwent flow cytometry to measure lymphocyte subpopulations. Results pPROM-newborns had fewer naïve CD4 T-cells, and more memory CD4 T-cells than control newborns. The effect was the same for increasing pPROM latency times before delivery. Gestational age and birth weight influenced maturation of the newborns' lymphocyte subpopulations and white blood cells, notably cytotoxic T-cells, regulatory T-cells, T-helper cells (absolute count), and CD4/CD8 ratio. Among morbidities, fewer naïve CD8 T-cells were found in bronchopulmonary dysplasia (BPD) (p=0.0009), and more T-helper cells in early onset sepsis (p=0.04). Conclusions pPROM prompts maturation of the newborn's T-cell immune system secondary to antigenic stimulation, which correlates with pPROM latency. Maternal immunity to inflammatory conditions is associated with a decrease in non-major histocompatibility complex (MHC)-restricted cytotoxic cells

Hyperoxia-induced changes in morphometric parameters of postnatal neurogenic sites in rat

In literature many works address the effects of hypoxia exposure on postnatal neurogenesis but few data are available about hyperoxia effects, although high oxygen concentrations are frequently used for ventilation of premature newborns. Thus, the aim of the present study was to compare with controls the morphometrical parameters of the main neurogenic sites (subventricular zone and dentate gyrus) in newborn Sprague-Dawley rats exposed to 60% or 95% oxygen for the first 14 postnatal days. Six rats were studied for each of the three groups. The unbiased quantitative method of the optical disector was applied to analyze neuronal densities, nuclear volumes, and total neuron numbers of the subventricular zone and hippocampal dentate gyrus. Apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling, TUNEL) and proliferation (Ki67) were also studied. The subventricular zone of newborn rats exposed to 95% hyperoxia showed statistically significant higher volume (mean value ± coefficient of variation: 0.40 ± 0.20 mm3) than subventricular zone of rats raised in normoxia (0.20 ± 0.11 mm3) or 60% hyperoxia (0.26 ± 0.18 mm3). Total neuron number was also significantly higher in 95% hyperoxia while neuronal densities did not reach statistically significant differences. TUNEL showed increased apoptotic indexes in hyperoxic rats. The percentage of proliferating KI67 positive cells was also higher in hyperoxia. The dentate gyrus granular layer of the normoxic rats showed higher volume (0.65 ± 0.11 mm3) than both the hyperoxic groups (60% hyperoxia: 0.39 ± 0.14 mm3; 95% hyperoxia: 0.36 ± 0.16 mm3). Total neuron numbers of hyperoxic dentate gyrus were also significantly reduced; neuronal densities were not modified. Hyperoxia-exposed rats also showed higher apoptotic and proliferating indexes in the dentate gyrus. Hyperoxia exposure in the first postnatal period may affect the main neurogenic areas (subventricular zone and dentate gyrus) increasing apoptosis but also inducing a certain reparative response consisting of increased proliferation. In particular, the increased volume of the subventricular zone may be ascribed to compensatory neurogenic response to the hyperoxic damage. Conversely, the decreased volume of the dentate gyrus granular layer could derive by a non sufficient neurogenic response to counterbalance the hyperoxic neuronal injury

L-citrulline is protective in hyperoxic lung damage and improves matrix remodelling and alveolarization

Moderate hyperoxia alters alveolar and vascular lung morphogenesis. Nitric oxide (NO) and matrix metalloproteinases (MMP) have a crucial role in the homeostasis of the matrix and bronchoalveolar structure and may be regulated abnormally by exposure to hyperoxia. Disruption of vascular endothelial growth factor (VEGF)-NO signaling impairs vascular growth and contributes to hyperoxia-induced vascular disease in bronchopulmonary dysplasia (BPD). We hypothesize that L-citrulline, by raising the serum levels of L-arginine and enhancing endogenous NO synthesis, might attenuate hyperoxia-induced lung injury in an experimental model of BPD. Neonatal rats (1 day old) were exposed to 60% oxygen or room air for 14 days and administered L-citrulline or a vehicle (sham). Lung morphometry were performed; Serum was tested for arginine level; Matrix metalloproteinases2 (MMP2) gene expression, VEGF gene and protein expression and endothelial NO synthase (eNOS) protein expression were compared. Mean linear intercept was higher in the hyperoxia and sham groups when compared with the room air (RA) and L-citr+hyperoxia treated group (p<0.02). Secondary crests number was higher in L-citrulline treated and RA when compared to hyperoxia and sham group (p<0.02). L-Arginine level rose in the L-citrulline-treated group (p<0.05). L-citrulline did not affect MMP2 gene expression, but it regulated the MMP2 active protein, which rose in bronchoalveolar lavage fluid (p<0.05), presumably due to a post-transductional effect. Compared with RA controls, hyperoxia significantly decreased VEGF and eNOS protein expression. At the same time, an increased lung VEGF gene and protein expression (p<0.05) were also seen in the rats treated with L-citrulline. We conclude that: (i) hyperoxia decreases growth and disrupts VEGF-NO signaling of lung; (ii) the main effects of L-citrulline are an increased serum level of arginine, as a promoter and a substrate of the nitric oxide synthase; and (ii) a better alveolar growth and matrix control than in hyperoxia-induced lung damage seems promising

Present and Future of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is the most common respiratory disorder among infants born extremely preterm. The pathogenesis of BPD involves multiple prenatal and postnatal mechanisms affecting the development of a very immature lung. Their combined effects alter the lung's morphogenesis, disrupt capillary gas exchange in the alveoli, and lead to the pathological and clinical features of BPD. The disorder is ultimately the result of an aberrant repair response to antenatal and postnatal injuries to the developing lungs. Neonatology has made huge advances in dealing with conditions related to prematurity, but efforts to prevent and treat BPD have so far been only partially effective. Seeing that BPD appears to have a role in the early origin of chronic obstructive pulmonary disease, its prevention is pivotal also in long-term respiratory outcome of these patients. There is currently some evidence to support the use of antenatal glucocorticoids, surfactant therapy, protective noninvasive ventilation, targeted saturations, early caffeine treatment, vitamin A, and fluid restriction, but none of the existing strategies have had any significant impact in reducing the burden of BPD. New areas of research are raising novel therapeutic prospects, however. For instance, early topical (intratracheal or nebulized) steroids seem promising: they might help to limit BPD development without the side effects of systemic steroids. Evidence in favor of stem cell therapy has emerged from several preclinical trials, and from a couple of studies in humans. Mesenchymal stromal/stem cells (MSCs) have revealed a reparatory capability, preventing the progression of BPD in animal models. Administering MSC-conditioned media containing extracellular vesicles (EVs) have also demonstrated a preventive action, without the potential risks associated with unwanted engraftment or the adverse effects of administering cells. In this paper, we explore these emerging treatments and take a look at the revolutionary changes in BPD and neonatology on the horizon

Exstrophy-Epispadias Complex in a Newborn: Case Report and Review of the Literature

Aim\u2003The aim of this report is to present a brief review of the current literature on the management of EEC. Case Report\u2003A term male neonate presented at birth with classic bladder exstrophy, a variant of the exstrophy-epispadias complex (EEC). The defect was covered with sterile silicon gauzes and waterproof dressing; at 72 hours of life, primary closure without osteotomy of bladder, pelvis, and abdominal wall was successfully performed. Discussion\u2003EEC incidence is approximately 2.15 per 1,00,000 live births; several urological, musculocutaneous, spinal, orthopedic, gastrointestinal, and gynecological anomalies may be associated to EEC. Initial medical management includes use of occlusive dressings to prevent air contact and dehydration of the open bladder template. Umbilical catheters should not be positioned. Surgical repair stages include initial closure of the bladder and abdominal wall with or without osteotomy, followed by epispadias repair at 6 to 12 months, and bladder neck repair around 5 years of life. Those who fail to attain continence eventually undergo bladder augmentation and placement of a catheterizable conduit. Conclusion\u2003Modern-staged repair of EEC guarantees socially acceptable urinary continence in up to 80% of cases; sexual function can be an issue in the long term, but overall quality of life can be good

Early Macrophage Activation in Preterm Newborns and Respiratory Disease

Monocyte-macrophages have a role in host defense and tissue remodeling. Classically activated (M1) and alternatively activated (M2) macrophages from preterm newborns are analyzed, and the role in acute respiratory distress syndrome (RDS) and bronchopulmonary dysplasia (BPD) is evaluated. Observational study was conducted on the blood samples (BSs) and tracheal aspirates (TAs) collected at 48 to 72 hours of life in preterm newborns. Flow-cytometry was performed to identify monocytes and M1 or M2. Prenatal factors, gestational age, birth weight, acute RDS and BPD were assessed and related to the M1 and M2 levels and M2/M1. One hundred nine subjects were included, and 100 were followed up. M1 and M2 increase and decrease, respectively, according to the gestational age and birth weight. Higher M2 and lower M1 levels in TAs were found after maternal chorioamnionitis. BPD patients have low M1 with high M2 in blood samples (BSs), as well as in tracheal aspirates (TAs). No relation was found between activation pattern and prenatal variables or the RDS grade. The correlation between gestational age or birth weight and M1 could reflect a more mature macrophage system, capable to push undifferentiated macrophages toward the classical pathway. We speculate that adequate early classical macrophage activation could be crucial to protect lungs from post-natal injuries, preventing the development of BPD

Brain Auditory Activation Measured by Near-Infrared Spectroscopy (NIRS) in Neonates

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Innate immunity ascertained from blood and tracheal aspirates of preterm newborn provides new clues for assessing bronchopulmonary dysplasia

The study aimed to establish how granulocytes, monocytes and macrophages contribute to the development of bronchopulmonary dysplasia (BPD)