Intrauterine neutrophil activation is associated with pulmonary haemorrhage in preterm infants

Prophylactic indomethacin and the risk of serious pulmonary hemorrhages in preterm infants less than 28 weeks' gestation

OBJECTIVE

To determine if prophylactic indomethacin (PINDO) decreases serious pulmonary hemorrhages in infants <28 weeks.

STUDY DESIGN

Intention-to-treat analysis of 615 consecutively admitted infants during four alternating protocol-driven epochs of PINDO or expectant patent ductus arteriosus (PDA) management.

RESULTS

41/615 (6.7%) developed serious pulmonary hemorrhage at 2 (1, 3) days (median (IQR)). In unadjusted and adjusted multivariable models, infants born in a PINDO epoch had significantly lower incidences of pulmonary hemorrhage and pulmonary hemorrhage or death before 7 days. There were less moderate/large PDA during PINDO epochs. The associations between PINDO and pulmonary hemorrhage and pulmonary hemorrhage/death were no longer significant when presence of a PDA was included in the analyses. There was no apparent association between PINDO epochs and the incidence of serious intraventricular hemorrhages.

CONCLUSION

Even though PINDO no longer appears to affect the incidence of sIVH it still is associated with a lower incidence of pulmonary hemorrhage.

Respiratory problems in preterm infants with pulmonary hemorrhage

AIM

Pulmonary hemorrhage is an important cause of morbidity and mortality in premature infants. There are few studies on pulmonary hemorrhage and associated morbidities observed in premature. The aim of this study was to investigate the possible relationship between pulmonary hemorrhage and respiratory problems in premature infants.

MATERIAL AND METHOD

Premature infants aged 25-32 weeks who were born between January 2014 and January 2018 in the neonatal intensive care unit were included to the study. Of these premature infants, 28 were patients diagnosed as pulmonary hemorrhage and 56 were control cases with the same demographic characteristics without pulmonary hemorrhage. From the medical records of infants; clinical course characteristics such as duration of ventilation, duration of oxygen supplementation, hospital stay were detailed. The data was analyzed statistically.

RESULTS

The duration of mechanical ventilation was significantly longer in the pulmonary bleeding group than in the control group (p: .001). There was a significant difference between the groups in terms of moderate and severe bronchopulmonary dysplasia (BPD) and the rate of BPD in the pulmonary hemorrhage group was higher than in the control group (17.2%-53.6%; p: .001). In addition, pulmonary hemorrhage group had significant patent ductus arteriosus (PDA) and preterm retinopathy (ROP) rate compared with control group.

DISCUSSION

This study implicated that, pulmonary hemorrhage is related with respiratory morbidities in preterm infants such as BPD and prolonged respiratory support. At the same time, the other morbidities such as ROP prolonged hospitalization are higher in infants with pulmonary hemorrhage.

CONCLUSION

In the follow-up of patients with pulmonary hemorrhage, defining respiratory problems and treatment and prophylaxis of comorbid conditions may be planned sooner.

Pulmonary Hemorrhage in the Neonate

Pulmonary hemorrhage (PH) is a pathology associated with significant morbidity and mortality, particularly among preterm infants in the NICU. The diagnosis is made when hemorrhagic secretions are aspirated from the trachea concurrent with respiratory decompensation that necessitates intubation or escalated support. The implementation of mechanical ventilation and widespread exogenous surfactant administration have significantly reduced respiratory morbidities. However, when PH develops, death remains the most common outcome. Treatment for PH remains primarily supportive; thus, a thorough understanding of underlying disease processes, manifestations, diagnostic testing, and current evidence is vital to enable early identification and proactive management to reduce morbidity and mortality.

Proteomics reveals region-specific hemostatic alterations in response to mechanical ventilation in a preterm lamb model of lung injury

INTRODUCTION

Preterm infants often require assisted ventilation, however ventilation when applied to the immature lung can initiate ventilator-induced lung injury (VILI). The biotrauma which underscores VILI is largely undefined, and is likely to involve vascular injury responses, including hemostasis. We aimed to use a ventilated, preterm lamb model to: (1) characterize regional alterations in hemostatic mediators within the lung and (2) assess the functional impact of protein alterations on hemostasis by analyzing temporal thrombin generation.

MATERIALS AND METHODS

Preterm lambs delivered at 124 to 127 days gestation received 90 min of mechanical ventilation (positive end-expiratory pressure = 8 cm H₂O, V_T = 6-8 ml/kg) and were compared with unventilated control lambs. At study completion, lung tissue was taken from standardized nondependent and gravity-dependent regions, and Orbitrap-mass spectrometry and KEGG were used to identify and map regional alterations in hemostasis pathway members. Temporal alterations in plasma thrombin generation were assessed.

RESULTS

Ventilation was distributed towards the nondependent lung. Significant changes in hemostatic protein abundance, were detected at a two-fold higher rate in the nondependent lung when compared with the gravity-dependent lung. Seven proteins were uniquely altered in non-dependent lung (SERPINA1, MYL12A, RAP1B, RHOA, ITGB1, A2M, GNAI2), compared with a single proteins in gravity-dependent lung (COL1A2). Four proteins were altered in both regions (VTN, FGG, FGA, and ACTB). Tissue protein alterations were mirrored by plasma hypocoagulability at 90-minutes of ventilation.

CONCLUSIONS

We observed regionally specific, hemostatic alterations within the preterm lung together with disturbed fibrinolysis following a short period of mechanical ventilation.

Neutrophil NETs in reproduction: from infertility to preeclampsia and the possibility of fetal loss

The intention of this review is to provide an overview of the potential role of neutrophil extracellular traps (NETs) in mammalian reproduction. Neutrophil NETs appear to be involved in various stages of the reproductive cycle, starting with fertility and possibly ending with fetal loss. The first suggestion that NETs may play a role in pregnancy-related disorders was in preeclampsia, where vast numbers were detected in the intervillous space of affected placentae. The induction of NETosis involved an auto-inflammatory component, mediated by the increased release of placental micro-debris in preeclampsia. This report was the first indicating that NETs may be associated with a human pathology not involving infection. Subsequently, NETs have since then been implicated in bovine or equine infertility, in that semen may become entrapped in the female reproductive tract during their passage to the oocyte. In this instance interesting species-specific differences are apparent, in that equine sperm evade entrapment via expression of a DNAse-like molecule, whereas highly motile bovine sperm, once free from seminal plasma (SP) that promotes interaction with neutrophils, appear impervious to NETs entrapment. Although still in the realm of speculation it is plausible that NETs may be involved in recurrent fetal loss mediated by anti-phospholipid antibodies, or perhaps even in fetal abortion triggered by infections with microorganisms such as L. monocytogenes or B. abortus.

A prediction score model for risk factors of mortality in neonate with pulmonary hemorrhage: the experience of single neonatal intensive care unit in Southwest China

AIM

To establish a prediction score model for mortality of neonates with pulmonary hemorrhage (PH).

METHODS

Mortality risk factors of PH were analyzed by logistic regression analysis in 244 neonates retrospectively. A prediction score model was developed according to regression coefficients of risk factors. The receiver operating characteristic curve (ROC) was also constructed and the cutoff was determined.

RESULTS

The overall mortality rate of PH was 74.59% (182/244). More patients from multiple pregnancies were found in the death group than in the survivor group (20.1% vs. 3.2%, P = 0.023). The survivor group infants had higher birth weight in average than death group infants (2,787 g vs. 2,339 g, P = 0.000). Significant differences were found between survivor and death groups in the rates of intraventricular hemorrhage (IVH) (25.8% vs. 53.8%, P = 0.000), heart failure (22.6% vs. 48.9%, P = 0.000) and sepsis (3.2% vs. 16.5%, P = 0.008). Birth weight, IVH, heart failure and sepsis were identified as independent mortality risk factors by logistic regression analysis. A score model predicting death was developed according to the regression coefficients, with a sensitivity of 0.846, a specificity of 0.661, a positive predictive value of 0.88 and a negative predictive value of 0.594 at a cutoff of 9 points. The low risk group, with a score of 9 or less, had a lower mortality rate as compared with the high risk group (40.6% vs. 88%, P = 0.000).

CONCLUSIONS

Low birth weight, IVH, heart failure and sepsis were the risk factors for mortality of PH. Those infants with a predictive score of more than 9 were at high risk for death.

Dysfunction of innate immunity and associated pathology in neonates

The neutrophils and complement system are the critical elements of innate immunity mainly due to participation in the first line of defense against microorganisms by means of phagocytosis, lysis of bacteria and activation of naive B-lymphocytes. In this report we provide an overview of the up to date information regarding the neutrophil and complement system's functional ability in newborn infants in association with the maternal conditions that exist during the intrauterine stage, gestational age and post-neonatal pathology. The neonates' capacity to control the neutrophil and complement protein activation process has also been discussed because of the evidence that uncontrolled activation of these immune elements provides a significant contribution to the tissue damage and subsequent pathology. The authors are confident that despite the many unanswered questions this review updates their knowledge and points the need for further research to clarify the role of the age-associated dysfunction of neutrophils and complement system in the infection and inflammation related pathology of newborn infants.