Role of selected cytokines in the etiopathogenesis of intraventricular hemorrhage in preterm newborns

Environmental uranium exposures and cytokine profiles among mother-newborn baby pairs from the Navajo Βirth Cohort Study

The Navajo Nation was heavily mined for uranium (U) during the cold-war leading to a legacy of >1100 abandoned U mining, milling and associated waste sites. The Navajo Birth Cohort Study was initiated to assess the effect of non-occupational legacy exposure to U during pregnancy on birth outcomes and child development. We report that 92% of babies with detectable urine U at birth were born from mothers who had urine U concentrations greater than national norms during pregnancy, indicative of prenatal exposure to U. To assess immune alterations associated with U exposure on both mothers and babies, we investigated associations between cytokine profiles and maternal U and associations of these measures with cytokine profiles in babies. Effect sizes for the differences in cytokine profiles were more evident among babies than mothers. Overall, there were seven cytokines (IFN-γ, IL-1β, IL-2, IL-4, IL-10, GM-CSF, and TNF-α), for which the effect size for babies with higher than the national U concentrations was medium to large (ORs of 2.21 (1.08-4.52) through 1.71(0.76-3.83). In contrast, only three cytokines (IL-8, IL-12p70, and TNF-α) had effect sizes which almost reached medium strength (ORs of 1.64 (0.74-4.05) through 1.36 (0.65-2.87) in mothers with U above national norms. The effects of prenatal exposures to uranium and associated alterations in systemic immune responses resulting from U exposure could impact both maternal health as well as healthy child development through induction of inflammation, autoimmunity or other chronic diseases related to immune dysfunction that may affect long-term health.

Treatment Strategies and Challenges to Avoid Cerebrospinal Fluid Shunting for Pediatric Hydrocephalus

Treatment for pediatric hydrocephalus aims not only to shrink the enlarged ventricle morphologically but also to create an intracranial environment that provides the best neurocognitive development and to deal with various treatment-related problems over a long period of time. Although the primary diseases that cause hydrocephalus are diverse, the ventricular peritoneal shunt has been introduced as the standard treatment for several decades. Nevertheless, complications such as shunt infection and shunt malfunction are unavoidable; the prognosis of neurological function is severely affected by such factors, especially in newborns and infants.

In recent years, treatment concepts have been attempted to avoid shunting, mainly in the context of pediatric cases. In this review, the current role of neuroendoscopic third ventriculostomy for noncommunicating hydrocephalus is discussed and a new therapeutic concept for post intraventricular hemorrhagic hydrocephalus in preterm infants is documented. To avoid shunt placement and achieve good neurodevelopmental outcomes for pediatric hydrocephalus, treatment modalities must be developed.

Fluid Homeostasis and Diuretic Therapy in the Neonate

Understanding physiologic water balance and homeostasis mechanisms in the neonate is critical for clinicians in the NICU as pathologic fluid accumulation increases the risk for morbidity and mortality. In addition, once this process occurs, treatment is limited. In this review, we will cover fluid homeostasis in the neonate, explain the implications of prematurity on this process, discuss the complexity of fluid accumulation and the development of fluid overload, identify mitigation strategies, and review treatment options.

The Relationship Between Cord Blood Cytokine Levels and Perinatal Characteristics and Bronchopulmonary Dysplasia: A Case-Control Study

OBJECTIVE

To establish the association between serial levels of inflammatory cytokines in cord blood and perinatal characteristics and bronchopulmonary dysplasia (BPD) in preterm infants.

METHODS

147 premature infants with gestational age ≤32 weeks who were born and hospitalized in the First Affiliated Hospital of Zhengzhou University between July 2019 and August 2021 were enrolled in this retrospective case-control study. Multiple microsphere flow immunofluorescence was used to detect seven cytokines in cord blood collected within 24 h of birth. Demographics, delivery characteristics, maternal factors, neonatal characteristics, and clinical outcomes were collected for the two groups. An unconditional logistic regression model was used in this study to assess the clinical variables.

RESULTS

IL-6 cord blood levels at birth were significantly higher in the BPD group than in the non-BPD group, but the odds ratio (OR) was very small (OR = 1). No differences in other cytokine concentrations were observed between the two groups. Multivariable logistic regression analysis demonstrated that increased maternal white blood cell (WBC) count on admission and lower birth weight increased the risk of BPD progression.

CONCLUSIONS

Increased IL-6 cord blood levels at birth in preterm infants may have trivial significance for predicting BPD. Furthermore, higher maternal WBC count on admission and lower birth weight increased the risk of BPD.

Preterm Intraventricular Hemorrhage-Induced Inflammatory Response in Human Choroid Plexus Epithelial Cells

Following an intraventricular hemorrhage (IVH), red blood cell lysis and hemoglobin (Hb) oxidation with the release of heme can cause sterile neuroinflammation. In this study, we measured Hb derivates and cellular adhesion molecules ICAM-1 and VCAM-1 with cell-free miRNAs in cerebrospinal fluid (CSF) samples obtained from Grade-III and Grade-IV preterm IVH infants (IVH-III and IVH-IV, respectively) at multiple time points between days 0–60 after the onset of IVH. Furthermore, human choroid plexus epithelial cells (HCPEpiCs) were incubated with IVH and non-IVH CSF (10 v/v %) for 24 h in vitro to investigate the IVH-induced inflammatory response that was investigated via: (i) HMOX1, IL8, VCAM1, and ICAM1 mRNAs as well as miR-155, miR-223, and miR-181b levels by RT-qPCR; (ii) nuclear translocation of the NF-κB p65 subunit by fluorescence microscopy; and (iii) reactive oxygen species (ROS) measurement. We found a time-dependent alteration of heme, IL-8, and adhesion molecules which revealed a prolonged elevation in IVH-IV vs. IVH-III with higher miR-155 and miR-181b expression at days 41–60. Exposure of HCPEpiCs to IVH CSF samples induced HMOX1, IL8, and ICAM1 mRNA levels along with increased ROS production via the NF-κB pathway activation but without cell death, as confirmed by the cell viability assay. Additionally, the enhanced intracellular miR-155 level was accompanied by lower miR-223 and miR-181b expression in HCPEpiCs after CSF treatment. Overall, choroid plexus epithelial cells exhibit an abnormal cell phenotype after interaction with pro-inflammatory CSF of IVH origin which may contribute to the development of later clinical complications in preterm IVH.

Spontaneous intestinal perforation in premature infants: a national study

OBJECTIVES

To assess the prevalence and outcomes of spontaneous intestinal perforation (SIP) in very low birth weight infants.

STUDY DESIGN

This cross-sectional study utilized the National Inpatient Sample dataset for the years 2002-2017. All premature infants with birth weight (BW) <1500 g and with gestational age (GA) ≤32 weeks were included. Analyses were repeated after stratifying the population into two BW sub-categories <1000 g and 1000-1499 g. Trend analysis was done using Cochran-Armitage test. Regression analysis was conducted to control for gestational age, race, and sex.

RESULT

A total of 658,001 infants were included. SIP (n = 10,443, 1.6%) was mostly (81.9%) in the category <1000 g with 89.9% ≤28 weeks of gestation. There was a significant trend for increased SIP over the years (p < 0.001). SIP was associated with increased mortality (aOR = 2.24, CI: 2.04-2.46, p < 0.001).

CONCLUSION

After controlling for gestational age and other confounders, SIP is associated with increased mortality in premature infants.

Efficacy and safety of intraventricular fibrinolytic therapy for post-intraventricular hemorrhagic hydrocephalus in extreme low birth weight infants: a preliminary clinical study

PURPOSE

To evaluate the efficacy and safety of our unique therapy for treating post-intraventricular hemorrhagic hydrocephalus (PIVHH) in low birth weight infants (LBWls) through an early stage fibrinolytic therapeutic strategy involving urokinase (UK) injection into the lateral ventricle, called the "Ventricular Lavage (VL) therapy."

METHODS

Overall, 43 consecutive infants with PIVHH were included. Most were extremely LBWIs (n = 39). Other cases included very LBWIs (n = 2) and full-term infants (n = 2). VL therapy involved continuous external ventricular drainage (EVD) management using a very fine catheter and intermittent slow injection of 6000 IU of UK every 3-6 h to actively dissolve hematomas.

RESULTS

Early EVD management (within 3 weeks of IVH onset) was performed in 25 infants, with combination VL therapy in 21 infants. Five initiated late EVD management (≥ 3 weeks after IVH onset); the remaining 13 were treated conservatively for several weeks, delaying surgical intervention. Eighteen of 21 (86%) infants who received VL therapy did not require permanent shunt surgery. There were no serious complications, including the absence of secondary hemorrhage and infection. Two-thirds of the infants treated in the late stages required permanent shunt, and various shunt-related complications frequently occurred. A good outcome occurred in 13/17 infants in the early treatment group, despite most subjects having an IVH grade IV, and in 6/15 in the late treatment group.

CONCLUSIONS

Permanent shunt surgery needs were dramatically reduced following early VL therapy, and functional outcomes were favorable. VL therapy might be a promising strategy that could lead to the development of new treatments for PIVHH.

Oxidative stress biomarkers in the preterm infant

Oxidative stress (OS) plays a key role in the pathophysiology of preterm infants. Accurate assessment of OS remains an analytical challenge that has been partially addressed during the last few decades. A plethora of approaches have been developed to assess preterm biofluids to demonstrate a link postnatally with preterm OS, giving rise to a set of widely employed biomarkers. However, the vast number of different analytic methods and lack of standardization hampers reliable comparison of OS-related biomarkers. In this chapter, we discuss approaches for the study of OS in prematurity with respect to methodologic considerations, the metabolic source of different biomarkers and their role in clinical studies.

Elevated Pro-Inflammatory Cell-Free MicroRNA Levels in Cerebrospinal Fluid of Premature Infants after Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) represents a high risk of neonatal mortality and later neurodevelopmental impairment in prematurity. IVH is accompanied with inflammation, hemolysis, and extracellular hemoglobin (Hb) oxidation. However, microRNA (miRNA) expression in cerebrospinal fluid (CSF) of preterm infants with IVH has been unknown. Therefore, in the present study, candidate pro-inflammatory cell-free miRNAs were analyzed in CSF samples from 47 preterm infants with grade III or IV IVH vs. clinical controls (n = 14). miRNAs were quantified by RT-qPCR, normalized to “spike-in” cel-miR-39. Oxidized Hb and total heme levels were determined by spectrophotometry as well as IL-8, VCAM-1, ICAM-1, and E-selectin concentrations by ELISA. To reveal the origin of the investigated miRNAs, controlled hemolysis experiments were performed in vitro; in addition, human choroid plexus epithelial cell (HCPEpiC) cultures were treated with metHb, ferrylHb, heme, or TNF-α to replicate IVH-triggered cellular conditions. Levels of miR-223, miR-155, miR-181b, and miR-126 as well as Hb metabolites along with IL-8 were elevated in CSF after the onset of IVH vs. controls. Significant correlations were observed among the miRNAs, oxidized Hb forms, and the soluble adhesion molecules. During the post-IVH follow-up, attenuated expression of miRNAs and protein biomarkers in CSF was observed upon elimination of Hb metabolites. These miRNAs remained unaffected by a series of artificially induced hemolysis, which excluded red blood cells as their origin, while stimulation of HCPEpiCs with oxidized Hb fractions and heme resulted in increased extracellular miRNA levels in the cell culture supernatant. Overall, the hemorrhage-induced CSF miRNAs reflected inflammatory conditions as potential biomarkers in preterm IVH.

Placental Pathology Findings and the Risk of Intraventricular and Cerebellar Hemorrhage in Preterm Neonates

Placental pathology as a predisposing factor to intraventricular hemorrhage remains a matter of debate, and its contribution to cerebellar hemorrhage development is still largely unexplored. Our study aimed to assess placental and perinatal risk factors for intraventricular and cerebellar hemorrhages in preterm infants. This retrospective cohort study included very low-birth weight infants born at the Gaslini Children's Hospital between January 2012 and October 2016 who underwent brain magnetic resonance with susceptibility-weighted imaging at term-equivalent age and whose placenta was analyzed according to the Amsterdam Placental Workshop Group Consensus Statement. Of the 286 neonates included, 68 (23.8%) had intraventricular hemorrhage (all grades) and 48 (16.8%) had a cerebellar hemorrhage (all grades). After correction for gestational age, chorioamnionitis involving the maternal side of the placenta was found to be an independent risk factor for developing intraventricular hemorrhage, whereas there was no association between maternal and fetal inflammatory response and cerebellar hemorrhage. Among perinatal factors, we found that intraventricular hemorrhage was significantly associated with cerebellar hemorrhage (odds ratio [OR], 8.14), mechanical ventilation within the first 72 h (OR, 2.67), and patent ductus arteriosus requiring treatment (OR, 2.6), whereas cesarean section emerged as a protective factor (OR, 0.26). Inotropic support within 72 h after birth (OR, 5.24) and intraventricular hemorrhage (OR, 6.38) were independent risk factors for cerebellar hemorrhage, whereas higher gestational age was a protective factor (OR, 0.76). Assessing placental pathology may help in understanding mechanisms leading to intraventricular hemorrhage, although its possible role in predicting cerebellar bleeding needs further evaluation.

Risk factors for the deterioration of periventricular-intraventricular hemorrhage in preterm infants

Preterm infants with periventricular–intraventricular hemorrhage (PV–IVH) have a high risk of neurological sequelae, with severity depending on the severity of the PV–IVH. Previous studies on the pathogenesis of PV–IVH have focused mainly on comparisons of perinatal risk factors between patients with and without PV–IVH. Notably, most cases of PV–IVH occur within the first 3 days after birth, and the condition may worsen within 1 week following the initial diagnosis. However, the risk factors that contribute to the deterioration of PV–IVH have not been investigated. In this cohort study, 514 PV–IVH infants with a gestational age (GA) < 32 weeks were enrolled. The dependent variable was initially diagnosed as mild PV–IVH (grade I or II) that subsequently progressed to severe PV–IVH (grade III or IV) within 1 week. A stepwise forward multivariate logistic regression model was adopted to select potential or related factors that affected the deterioration of PV–IVH in preterm infants. Overall, 42 of the 514 infants with PV–IVH (8.2%) showed deterioration within 1 week. The results showed that maternal lower genital tract infection (OR 3.73, 95% CI 1.75–7.95) was an independent risk factor for PV–IVH deterioration. Higher GA (OR 0.62, 95% CI 0.48–0.80) was a protective factor. Our results suggest that maternal lower genital tract infection and a lower GA may contribute to PV–IVH deterioration in preterm infants.

The impact of placental massive perivillous fibrin deposition on neonatal outcome in pregnancies complicated by fetal growth restriction

INTRODUCTION

Massive perivillous fibrin deposition (MPDD) is an uncommon placental lesion which has been associated with an increased risk of adverse pregnancy outcome in retrospective series. The purpose of the study was to evaluate the frequency and consequences of MPFD in pregnancies complicated by fetal growth restriction (FGR).

MATERIALS AND METHODS

A cohort study of 355 pregnancies complicated by FGR diagnosed according to standard ultrasonographic criteria, enrolled, followed and delivered at a single obstetric unit. Pathological placental lesions were classified according to the Amsterdam Placental Workshop Consensus. Penalized logistic regression models were used to evaluate the association of MPFD with maternal risk factors, other pathological lesions and neonatal outcome.

RESULTS

The rates of moderate (25-50% of villi) and severe (>50% of villi) MPFD were 8.7% (31/355) and 3.1% (11/355), respectively. Compared to other FGR cases, MPFD pregnancies were characterized by higher placental volume (450 ± 144.5 SD as compared to 412.2 ± 151 cm³,p < 0.001) and lower birthweight/placental weight ratio (5.32 ± 1.53 compared to 6.1 ± 1.52,p < 0.001). The rates of abnormal Doppler ultrasound studies of umbilical and middle cerebral artery were similar in MPFD subjects and controls. After correction for gestational age and birthweight, MPFD was associated with an increased risk of neonatal intraventricular hemorrhage (>grade II) (OR = 5.66,95% CI = 1.69-18.97), sepsis (OR = 5.9, 95% CI = 1.27-27.12), proven necrotizing enterocolitis (OR = 9.84,95% CI = 2.49-38.8) and overall severe adverse neonatal outcome (OR = 5.71,95% CI = 2.05-15.87).

CONCLUSIONS

Moderate-to-severe MPFD was relatively common among FGR pregnancies and was associated with morphometric modifications of placenta and with an increased risk of severe adverse neonatal outcome.

Preterm brain injury: Germinal matrix-intraventricular hemorrhage and post-hemorrhagic ventricular dilatation

Germinal matrix hemorrhage and intraventricular hemorrhages (GMH-IVH) remain a common and clinically significant problem in preterm infants, particularly extremely preterm infants. A large GMH-IVH is often complicated by posthemorrhagic ventricular dilation (PHVD) or parenchymal hemorrhagic infarction and is associated with an increased risk of adverse neurologic sequelae. The widespread use of cranial ultrasonography since the early 1980s has shown a gradual decrease in the incidence of GMH-IVH and has helped with the identification of antenatal and perinatal risk factors and timing of the lesion. The increased use of magnetic resonance imaging (MRI) has contributed to more detailed visualization of the site and extent of the GMH-IVH. In addition, MRI has contributed to the awareness of associated white matter changes as well as associated cerebellar hemorrhages. Although GMH-IVH and PHVD still cannot be prevented, cerebrospinal fluid drainage initiated in the early stage of PHVD development seems to be associated with a better neurodevelopmental outcome. Further studies are underway to improve treatment strategies for PHVD and to potentially prevent and repair GMH-IVH and PHVD and associated brain injury. This chapter discusses the pathogenesis, incidence, risk factors, and management, including preventive measures, of GHM-IVH and PHVD.

De Novo Transcriptome Sequencing Analysis of Goose (Anser anser) Embryonic Skin and the Identification of Genes Related to Feather Follicle Morphogenesis at Three Stages of Development

The objective of this study was to evaluate the changes in the goose embryo transcriptome during feather development. RNA-Sequencing (RNA-Seq) was used to find the transcriptome profiles of feather follicles from three stages of embryonic dorsal skin at embryonic day 13, 18, and 28 (E13, E18, E28). The results showed that 3001, 6634, and 13,780 genes were differently expressed in three stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that differentially expressed genes (DEGs) in E13 vs. E18 were significantly mapped into the GO term of extracellular structure organization and the pathway of extracellular matrix (ECM)-receptor interaction. In E18 vs. E28, the top significantly mapped into GO term was the single-organism developmental process; the pathway was also the ECM-receptor interaction. DEGs in E13 vs. E28 were significantly mapped into the GO term of the multicellular organismal process and the pathway of cell adhesion molecules. Subsequently, the union of DEGs was categorized by succession cluster into eight profiles, which were then grouped into four ideal profiles. Lastly, the seven genes spatio-temporal expression pattern was confirmed by real-time PCR. Our findings advocate that interleukin 20 receptor subunit alpha (IL20RA), interleukin 6 receptor (IL6R), interleukin 1 receptor type 1 (IL-1R1), Wnt family member 3A (WNT3A), insulin-like growth factor binding protein 3 (IGFBP3), bone morphogenetic protein 7 (BMP7), and secreted-frizzled related protein 2 (SFRP2) might possibly play vital roles in skin and feather follicle development and growth processes.

Maternal body mass index and risk of intraventricular hemorrhage in preterm infants

BackgroundIntraventricular hemorrhage (IVH) and pre-pregnancy obesity and underweight have been linked to inflammatory states. We hypothesize that IVH in preterm infants is associated with pre-pregnancy obesity and underweight due to an inflammatory intrauterine environment.MethodsPopulation-based study of infants born between 22 and 32 weeks' gestation from 2007 to 2011. Data were extracted from vital statistics and the California Perinatal Quality Care Collaborative. Results were examined for all cases (any IVH) and for severe IVH.ResultsAmong 20,927 infants, 4,818 (23%) had any IVH and 1,514 (7%) had severe IVH. After adjustment for confounders, there was an increased risk of IVH associated with pre-pregnancy obesity, relative risk 1.14 (95% confidence interval (CI) 1.06, 1.32) for any IVH, and 1.25 (85% CI 1.10, 1.42) for severe IVH. The direct effect of pre-pregnancy obesity on any IVH was significant (P<0.001) after controlling for antenatal inflammation-related conditions, but was not significant after controlling for gestational age (P=0.56).ConclusionPre-pregnancy obesity was found to be a risk factor for IVH in preterm infants; however, this relationship appeared to be largely mediated through the effect of BMI on gestational age at delivery. The etiology of IVH is complex and it is important to understand the contributing maternal factors.

Maternal, fetal and perinatal factors associated with necrotizing enterocolitis in Sweden. A national case-control study

OBJECTIVE

To analyze associations of maternal, fetal, gestational, and perinatal factors with necrotizing enterocolitis in a matched case-control study based on routinely collected, nationwide register data.

STUDY DESIGN

All infants born in 1987 through 2009 with a diagnosis of necrotizing enterocolitis in any of the Swedish national health care registers were identified. For each case up to 6 controls, matched for birth year and gestational age, were selected. The resulting study population consisted of 720 cases and 3,567 controls. Information on socioeconomic data about the mother, maternal morbidity, pregnancy related diagnoses, perinatal diagnoses of the infant, and procedures in the perinatal period, was obtained for all cases and controls and analyzed with univariable and multivariable logistic regressions for the whole study population as well as for subgroups according to gestational age.

RESULTS

In the study population as a whole, we found independent positive associations with necrotizing enterocolitis for isoimmunization, fetal distress, cesarean section, neonatal bacterial infection including sepsis, erythrocyte transfusion, persistent ductus arteriosus, cardiac malformation, gastrointestinal malformation, and chromosomal abnormality. Negative associations were found for maternal weight, preeclampsia, maternal urinary infection, premature rupture of the membranes, and birthweight. Different patterns of associations were seen in the subgroups of different gestational age.

CONCLUSION

With some interesting exceptions, especially in negative associations, the results of this large, population based study, are in keeping with earlier studies. Although restrained by the limitations of register data, the findings mirror conceivable pathophysiological processes and underline that NEC is a multifactorial disease.

Chemokine and cytokine levels in the lumbar cerebrospinal fluid of preterm infants with post-hemorrhagic hydrocephalus

BACKGROUND

Neuroinflammation has been implicated in the pathophysiology of post-hemorrhagic hydrocephalus (PHH) of prematurity, but no comprehensive analysis of signaling molecules has been performed using human cerebrospinal fluid (CSF).

METHODS

Lumbar CSF levels of key cytokines (IL-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, IL-12, TNF-α, TGF-β1, IFN-γ) and chemokines (XCL-1, CCL-2, CCL-3, CCL-19, CXCL-10, CXCL-11, CXCL-12) were measured using conventional and multiplexed Enzyme-linked Immunosorbent Assays and compared between preterm infants with PHH and those with no known neurological injury. The relationships between individual biomarker levels and specific CSF cell counts were examined.

RESULTS

Total protein (TP) CSF levels were elevated in the PHH subjects compared to controls. CSF levels of IL-1α, IL-4, IL-6, IL-12, TNF-α, CCL-3, CCL-19, and CXCL-10 were significantly increased in PHH whereas XCL-1 was significantly decreased in PHH. When normalizing by TP, IL-1α, IL-1β, IL-10, IL-12, CCL-3, and CCL-19 levels were significantly elevated compared to controls, while XCL-1 levels remained significantly decreased. Among those with significantly different levels in both absolute and normalized levels, only absolute CCL-19 levels showed a significant correlation with CSF nucleated cells, neutrophils, and lymphocytes. IL-1β and CXCL-10 also were correlated with total cell count, nucleated cells, red blood cells, and neutrophils.

CONCLUSIONS

Neuroinflammation is likely to be an important process in the pathophysiology of PHH. To our knowledge, this is the first study to investigate CSF levels of chemokines in PHH as well as the only one to show XCL-1 selectively decreased in a diseased state. Additionally, CCL-19 was the only analyte studied that showed significant differences between groups and had significant correlation with cell count analysis. The selectivity of CCL-19 and XCL-1 should be further investigated. Future studies will further delineate the role of these cytokines and chemokines in PHH.

In Premature Newborns Intraventricular Hemorrhage Causes Cerebral Vasospasm and Associated Neurodisability via Heme-Induced Inflammasome-Mediated Interleukin-1 Production and Nitric Oxide Depletion

BACKGROUND

Intraventricular hemorrhage (IVH) occurs in 60-70% of neonates weighing 500-750 g and 10-20% of those weighing 1,000-1,500 g. All forms of IVH have been associated with neurocognitive deficits. Both subarachnoid and IVHs have been associated with delayed vasospasm leading to neurological deficits. Pathways linking hemoglobin release from blood clots to vasospasm include heme-induced activation of inflammasomes releasing interleukin-1 (IL-1) that can cause calcium dependent and independent vasospasm. Free hemoglobin is a potent scavenger of nitric oxide (NO). Depletion of NO, a potent endogenous vasodilator, has been associated with features of vasospasm.

HYPOTHESIS

In premature newborns, IVH causes cerebral vasospasm and associated neurodisability via heme-induced increased inflammasome-mediated IL-1 production and NO depletion.

CONFIRMATION OF HYPOTHESIS AND IMPLICATIONS

This hypothesis could be confirmed in the IVH animal model with visualization of any associated vasospasm by angiography and in newborns with IVH by transcranial Doppler ultrasonography and correlation with cerebrospinal fluid IL-1 and NO metabolite levels. Confirmation of the role of heme in activation of inflammasomes causing IL-1 production and NO binding could be achieved by measuring the effect of heme scavenging interventions on IL-1 levels and levels of NO metabolites. In addition to removal of the accumulated blood of an IVH by drainage, irrigation, and fibrinolytic therapy intrathecal application of vasodilators and heme scavenging agents like haptoglobin and haemopexin and systemic treatment with inhibitors of inflammasomes like telmisartan could be used to prevent and treat cerebral vasospasm, and thus reduce the risk of associated brain injury in premature neonates.

Leading causes of preterm delivery as risk factors for intraventricular hemorrhage in very preterm infants: results of the EPIPAGE 2 cohort study

BACKGROUND

Intraventricular hemorrhage is a major risk factor for neurodevelopmental disabilities in preterm infants. However, few studies have investigated how pregnancy complications responsible for preterm delivery are related to intraventricular hemorrhage.

OBJECTIVE

We sought to investigate the association between the main causes of preterm delivery and intraventricular hemorrhage in very preterm infants born in France during 2011 between 22-31 weeks of gestation.

STUDY DESIGN

The study included 3495 preterm infants from the national EPIPAGE 2 cohort study who were admitted to neonatal intensive care units and had at least 1 cranial ultrasound assessment. The primary outcome was grade I-IV intraventricular hemorrhage according to the Papile classification. Multinomial logistic regression models were used to study the relationship between risk of intraventricular hemorrhage and the leading causes of preterm delivery: vascular placental diseases, isolated intrauterine growth retardation, placental abruption, preterm labor, and premature rupture of membranes, with or without associated maternal inflammatory syndrome.

RESULTS

The overall frequency of grade IV, III, II, and I intraventricular hemorrhage was 3.8% (95% confidence interval, 3.2-4.5), 3.3% (95% confidence interval, 2.7-3.9), 12.1% (95% confidence interval, 11.0-13.3), and 17.0% (95% confidence interval, 15.7-18.4), respectively. After adjustment for gestational age, antenatal magnesium sulfate therapy, level of care in the maternity unit, antenatal corticosteroids, and chest compressions, infants born after placental abruption had a higher risk of grade IV and III intraventricular hemorrhage compared to those born under placental vascular disease conditions, with adjusted odds ratios of 4.3 (95% confidence interval, 1.1-17.0) and 4.4 (95% confidence interval, 1.1-17.6), respectively. Similarly, preterm labor with concurrent inflammatory syndrome was associated with an increased risk of grade IV intraventricular hemorrhage (adjusted odds ratio, 3.4; 95% confidence interval, 1.1-10.2]). Premature rupture of membranes did not significantly increase the risk.

CONCLUSION

Relationships between the causes of preterm birth and intraventricular hemorrhage were limited to specific and rare cases involving acute hypoxia-ischemia and/or inflammation. While the emergent nature of placental abruption would challenge any attempts to optimize management, the prenatal care offered during preterm labor could be improved.

The significance of polymorphisms in genes encoding Il-1β, Il-6, TNFα, and Il-1RN in the pathogenesis of intraventricular hemorrhage in preterm infants

INTRODUCTION

Intraventricular hemorrhage (IVH) is a significant morbidity seen in very low birth weight infants. Genes related to inflammation may be risk factors for IVH.

MATERIAL AND METHODS

We examined five polymorphisms for an association with IVH in 100 preterm infants born from singleton pregnancy, before 32 + 0 weeks of gestation, exposed to antenatal steroid therapy, and without congenital abnormalities. These polymorphisms include interleukin-1β 3953 C>T, interleukin-6 -174G>C and -596G>A, tumor necrosis factor -308 G>A, and 86 bp variable number tandem repeat polymorphism of interleukin-1 receptor antagonist (Il -1RN 86 bp VNTR).

RESULTS

In our study population, 45 (45%) infants developed IVH, including 15 (33.33%) with stage 1, 19 (42.22%) with stage 2, 8 (17.77%) with stage 3, and 3 (6.66%) with stage 4. In contrast to the previously published data, the prevalence of IVH did not vary between infants with different IL-6 and TNFα alleles and genotypes. Our novel investigations in Il-1 +3953 C>T and Il-1RN 86 bp VNTR polymorphism did not show any significant link between those alleles or genotypes and IVH.

CONCLUSIONS

IVH is a significant problem for preterm infants. In addition to little progress in preventing IVH in preterm babies, substantial research that are focused on understanding the etiology, mechanism and risk factors for IVH are imperative. In the era of personalized medicine, identification of genetic risk factors creates opportunities to generate preventative strategies. Further studies should be performed to confirm the role of genetic factors in etiology and pathogenesis of IVH.