Increased serum levels of interleukin 6 are associated with severe intraventricular haemorrhage in extremely premature infants

Early changes in serum interleukin-6 levels in extremely premature newborns for detecting fetal inflammation

BACKGROUND

Fetal inflammatory response syndrome (FIRS) is defined by elevated levels of inflammatory cytokines circulating in fetal blood, which may result in preterm morbidities. Serum interleukin-6 (IL-6) level has been reported to be a good indicator of FIRS; however, changes in IL-6 levels after birth remain to be elucidated. Herein, we characterized early changes in serum IL-6 levels in extremely premature newborns (EPNs, < 28 wks gestation), and then determined the cut-off values for detecting fetal inflammation at each postnatal epoch.

METHODS

In this single-center study, 49 EPNs were retrospectively studied. Serum IL-6 measurements are routinely performed at delivery, 1-3, 6-12, and 24-36 h of life. Receiver operating characteristic (ROC) curve analyses were performed for detecting the presence of funisitis, the histologic counterpart of FIRS.

RESULTS

Overall, serum IL-6 levels were significantly elevated at 1-3 (298 [31-4719] pg/mL) and 6-12 (29 [2-12,635] pg/mL) hours of life, then returned to at-delivery levels at 24-36 h of life. When comparing serum IL-6 levels at each postnatal epoch, the levels at delivery, 1-3, and 6-12 h of life were significantly higher in the EPNs with funisitis. Serum IL-6 cut-off values at delivery, 1-3, 6-12, and 24-36 h of life for the presence of funisitis were 20, 572, 290, and 13 pg/mL with area under ROCs of 0.75, 0.71, 0.68, and 0.53, respectively.

CONCLUSIONS

Serum IL-6 levels in EPNs significantly increase early after birth, then decrease to at-delivery levels by 24-36 h of life. Therefore, postnatal age-dependent cut-off values of serum IL-6 might be considered for detecting fetal inflammation with confirmed funisitis.

Mechanical ventilation induces brainstem inflammation in preterm fetal sheep

Background

Preterm infants have immature respiratory drive and often require prolonged periods of mechanical ventilation. Prolonged mechanical ventilation induces systemic inflammation resulting in ventilation-induced brain injury, however its effect on brainstem respiratory centers is unknown. We aimed to determine the effects of 24 h of mechanical ventilation on inflammation and injury in brainstem respiratory centres of preterm fetal sheep.

Methods

Preterm fetal sheep at 110 ± 1 days (d) gestation were instrumented to provide mechanical ventilation in utero. At 112 ± 1 d gestation, fetuses received either mechanical ventilation (VENT; n = 7; 3 ml/kg) for 24 h, or no ventilation (CONT; n = 6). At post-mortem, fetal brainstems were collected for assessment of mRNA and histological markers of inflammation and injury.

Results

In utero ventilation (IUV) did not alter any blood-gas parameters. IUV significantly increased systemic IL-6 and IL-8 concentrations over the 24 h period compared to CONT. The number of ameboid microglia within the nucleus tractus solitarius and the raphe nucleus increased in VENT fetuses (p < 0.05 for both vs. control). The % area fraction of GFAP + staining was not significantly higher within the preBötzinger complex (p = 0.067) and retrotrapezoid nucleus and parafacial respiratory group (p = 0.057) in VENT fetuses compared to CONT. Numbers of caspase-3 and TUNEL-positive cells were similar between groups. Gene expression (mRNA) levels of inflammation, injury, cell death and prostaglandin synthesis within the brainstem were similar between groups.

Conclusion

Mechanical ventilation induces a systemic inflammatory response with only moderate inflammatory effects within the brainstem respiratory centres of preterm fetal sheep.

Intracranial hemorrhages in infants of diabetic mothers: A national cohort study

OBJECTIVE

To assess the association of maternal diabetes mellitus (DM) with intraventricular hemorrhage (IVH) and other intracranial hemorrhages (ICH) in newborns.

STUDY DESIGN

We analyzed the National Inpatient Sample dataset and compared prevalence of IVH and other subtypes of ICH in infants of diabetic mothers (IDMs) vs. those born to mothers without DM. Regression models were used to control for demographic and clinical confounding variables.

RESULT

A total of 11,318,691 infants were included. Compared to controls, IDMs had increased prevalence of IVH (aOR = 1.18, CI: 1.12-1.23, p < 0.001) and other ICH (aOR = 1.18, CI: 1.07-1.31, p = 0.001). Severe IVH (grades 3 & 4) was encountered less frequently in IDMs (aOR = 0.75, CI: 0.66-0.85, p < 0.001) than controls. Gestational DM was not associated with increased IVH after controlling for the demographic, clinical and perinatal confounders in the logistic regression model (aOR = 1.04, CI: 0.98-1.11, p = 0.22).

CONCLUSION

Chronic maternal DM is associated with increased neonatal IVH and other ICH but not severe IVH. This association needs to be confirmed in further studies.

Systemic Cytokines in Retinopathy of Prematurity

Retinopathy of prematurity (ROP), a vasoproliferative vitreoretinal disorder, is the leading cause of childhood blindness worldwide. Although angiogenic pathways have been the main focus, cytokine-mediated inflammation is also involved in ROP etiology. Herein, we illustrate the characteristics and actions of all cytokines involved in ROP pathogenesis. The two-phase (vaso-obliteration followed by vasoproliferation) theory outlines the evaluation of cytokines in a time-dependent manner. Levels of cytokines may even differ between the blood and the vitreous. Data from animal models of oxygen-induced retinopathy are also valuable. Although conventional cryotherapy and laser photocoagulation are well established and anti-vascular endothelial growth factor agents are available, less destructive novel therapeutics that can precisely target the signaling pathways are required. Linking the cytokines involved in ROP to other maternal and neonatal diseases and conditions provides insights into the management of ROP. Suppressing disordered retinal angiogenesis via the modulation of hypoxia-inducible factor, supplementation of insulin-like growth factor (IGF)-1/IGF-binding protein 3 complex, erythropoietin, and its derivatives, polyunsaturated fatty acids, and inhibition of secretogranin III have attracted the attention of researchers. Recently, gut microbiota modulation, non-coding RNAs, and gene therapies have shown promise in regulating ROP. These emerging therapeutics can be used to treat preterm infants with ROP.

Perinatal Stroke in Fetuses, Preterm and Term Infants

Perinatal stroke is a well-defined heterogenous group of disorders involving a focal disruption of cerebral blood flow between 20 weeks gestation and 28 days of postnatal life. The most focused lifetime risk for stroke occurs during the first week after birth. The morbidity of perinatal stroke is high, as it is the most common cause of hemiparetic cerebral palsy which results in lifelong disability that becomes more apparent throughout childhood. Perinatal strokes can be classified by the timing of diagnosis (acute or retrospective), vessel involved (arterial or venous), and underlying cause (hemorrhagic or ischemic). Perinatal stroke has primarily been reported as a disorder of term infants; however, the preterm brain possesses different vulnerabilities that predispose an infant to stroke injury both in utero and after birth. Accurate diagnosis of perinatal stroke syndromes has important implications for investigations, management, and prognosis. The classification of perinatal stroke by age at presentation (fetal, preterm neonatal, term neonatal, and infancy/childhood) is summarized in this review, and includes detailed descriptions of risk factors, diagnosis, treatment, outcomes, controversies, and resources for family support.

Serial Measurement of Interleukin-6 Enhances Chance to Exclude Early-Onset Sepsis in Very Preterm Infants

The aim of this retrospective study was to evaluate the reliability of peak interleukin-6 (IL-6) level within 24 hours after delivery as a predictor for early-onset sepsis (EOS) in very preterm neonates. Interleukin-6 was assessed at 2 hours and at 12 to 24 hours after delivery. The highest level was considered a peak value. The definition of EOS was based on positive blood culture and clinical signs of infection or negative blood culture, clinical signs of infection, and C-reactive protein >10 mg/L. Among 445 enrolled infants, 53 developed EOS. A peak IL-6 level of more than 200 ng/L had a sensitivity of 89% and specificity of 77% for the presence of EOS. The negative predictive value was 98%. Receiver operating characteristics curve had area under the curve of 0.92. Peak IL-6 is a reliable marker of systemic inflammatory response and might be useful to exclude EOS within the first 24 hours.

Neonatal Sequential Organ Failure Assessment (nSOFA) Score within 72 Hours after Birth Reliably Predicts Mortality and Serious Morbidity in Very Preterm Infants

The aim of this study was to assess the applicability of the neonatal sequential organ failure assessment score (nSOFA) within 72 h after delivery as a predictor for mortality and adverse outcome in very preterm neonates. Inborn neonates <32 weeks of gestation were evaluated. The nSOFA scores were calculated from medical records in the first 72 h after birth and the peak value was used for analysis. Death or composite morbidity at hospital discharge defined the adverse outcome. Composite morbidity consisted of chronic lung disease, intraventricular haemorrhage ≥grade III, periventricular leukomalacia and necrotizing enterocolitis. Among 423 enrolled infants (median birth weight 1070 g, median gestational age 29 weeks), 27 died and 91 developed composite morbidity. Death or composite morbidity was associated with organ dysfunction as assessed by nSOFA, systemic inflammatory response, and low birthweight. The score >2 was associated with OR 2.5 (CI 1.39−4.64, p = 0.002) for the adverse outcome. Area under the curve of ROC was 0.795 (95% CI = 0.763−0.827). The use of nSOFA seems to be reasonable for predicting mortality and morbidity in very preterm infants. It constitutes a suitable basis to measure the severity of organ dysfunction regardless of the cause.

Role of the Endothelium in Neonatal Diseases

In both fetal and neonatal physiologic and pathologic processes in most organs, endothelial cells are known to play critical roles. Although the endothelium is one of the most ubiquitous cell type in the body, the tight adherence to the blood vessel wall has made it difficult to study their diverse function and structure. In this article, we have reviewed endothelial cell origins and explored their heterogeneity in terms of structure, function, developmental changes, and their role in inflammatory and infectious diseases. We have also attempted to evaluate the untapped therapeutic potentials of endothelial cells in neonatal disease. This article comprises various peer-reviewed studies, including ours, and an extensive database literature search from EMBASE, PubMed, and Scopus.

Effects of nutrition therapy on growth, inflammation and metabolism in immature infants: a study protocol of a double-blind randomized controlled trial (ImNuT)

Background

Current nutritional management of infants born very preterm results in significant deficiency of the essential fatty acids (FAs) arachidonic acid (ARA) and docosahexaenoic acid (DHA). The impact of this deficit on brain maturation and inflammation mediated neonatal morbidities are unknown. The aim of this study is to determine whether early supply of ARA and DHA improves brain maturation and neonatal outcomes in infants born before 29 weeks of gestation.

Methods

Infants born at Oslo University Hospital are eligible to participate in this double-blind randomized controlled trial. Study participants are randomized to receive an enteral FA supplement of either 0.4 ml/kg MCT-oil™ (medium chain triglycerides) or 0.4 ml/kg Formulaid™ (100 mg/kg of ARA and 50 mg/kg of DHA). The FA supplement is given from the second day of life to 36 weeks’ postmenstrual age (PMA). The primary outcome is brain maturation assessed by Magnetic Resonance Imaging (MRI) at term equivalent age. Secondary outcomes include quality of growth, incidence of neonatal morbidities, cardiovascular health and neuro-development. Target sample size is 120 infants (60 per group), this will provide 80% power to detect a 0.04 difference in mean diffusivity (MD, mm²/sec) in major white matter tracts on MRI.

Discussion

Supplementation of ARA and DHA has the potential to improve brain maturation and reduce inflammation related diseases. This study is expected to provide valuable information for future nutritional guidelines for preterm infants.

Trial registration

Clinicaltrials.gov ID: NCT03555019. Registered 4 October 2018- Retrospectively registered.

Elevated International Normalized Ratio (INR) is Associated With an Increased Risk of Intraventricular Hemorrhage in Extremely Preterm Infants

INTRODUCTION

The international normalized ratio (INR), a standardized method of reporting the prothrombin time, can be a surrogate marker of the vitamin K-dependent coagulation pathways.

OBJECTIVE

To evaluate the relationship between INR measurements in the first 48 hours of life and subsequent development of intraventricular hemorrhage (IVH) in extremely preterm infants.

MATERIALS AND METHODS

A single-center retrospective, observational cohort study of infants born at <28 weeks gestation. The main outcome measure was defined as the degree of IVH seen on cranial ultrasound examinations at day 7 postnatal age.

RESULTS

Of 200 infants, 109 (mean gestational age, 25.2 wk [SD, 1.27]) had coagulation results available. Of 109, 26 developed IVH. Elevated INR was associated with increased risk of a severe IVH (odds ratio [OR] 6.50; 95% confidence interval [CI], 1.65-25.62; P=0.008) adjusted for gestation, birth weight, and sex. INR was significantly associated with severe IVH in infants who did not receive blood products (OR, 64.60; 95% CI, 1.35-3081.25; P=0.035), but not in those who did (OR, 2.93; 95% CI, 0.67-12.71; P=0.151) (Pinteraction=0.086).

CONCLUSION

An elevated INR in the first 48 hours of life may be useful to identify preterm infants at risk of severe IVH and may guide strategies to prevent the development, or limit the extension, of IVH.

Glutamate Transport and Preterm Brain Injury

Preterm birth complications are the leading cause of child death worldwide and a top global health priority. Among the survivors, the risk of life-long disabilities is high, including cerebral palsy and impairment of movement, cognition, and behavior. Understanding the molecular mechanisms of preterm brain injuries is at the core of future healthcare improvements. Glutamate excitotoxicity is a key mechanism in preterm brain injury, whereby the accumulation of extracellular glutamate damages the delicate immature oligodendrocytes and neurons, leading to the typical patterns of injury seen in the periventricular white matter. Glutamate excitotoxicity is thought to be induced by an interaction between environmental triggers of injury in the perinatal period, particularly cerebral hypoxia-ischemia and infection/inflammation, and developmental and genetic vulnerabilities. To avoid extracellular build-up of glutamate, the brain relies on rapid uptake by sodium-dependent glutamate transporters. Astrocytic excitatory amino acid transporter 2 (EAAT2) is responsible for up to 95% of glutamate clearance, and several lines of evidence suggest that it is essential for brain functioning. While in the adult EAAT2 is predominantly expressed by astrocytes, EAAT2 is transiently upregulated in the immature oligodendrocytes and selected neuronal populations during mid-late gestation, at the peak time for preterm brain injury. This developmental upregulation may interact with perinatal hypoxia-ischemia and infection/inflammation and contribute to the selective vulnerability of the immature oligodendrocytes and neurons in the preterm brain. Disruption of EAAT2 may involve not only altered expression but also impaired function with reversal of transport direction. Importantly, elevated EAAT2 levels have been found in the reactive astrocytes and macrophages of human infant post-mortem brains with severe white matter injury (cystic periventricular leukomalacia), potentially suggesting an adaptive mechanism against excitotoxicity. Interestingly, EAAT2 is suppressed in animal models of acute hypoxic-ischemic brain injury at term, pointing to an important and complex role in newborn brain injuries. Enhancement of EAAT2 expression and transport function is gathering attention as a potential therapeutic approach for a variety of adult disorders and awaits exploration in the context of the preterm brain injuries.

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.

Risk factors associated with intraventricular hemorrhage in extremely premature neonates

: Intraventricular hemorrhage (IVH) is a significant cause of morbidity in extremely premature infants despite many advances in neonatal intensive care. We conducted an institutional retrospective review aimed to correlate risk factors associated with IVH. Clinical variables reported to the Vermont-Oxford Network on less than 30 weeks gestational age infants over a 5-year period were evaluated with Pearson's chi-square and multivariate logistic regression. Of 618 infants born less than 30-week gestational age, 178 (28.8%) experienced IVH. Of those less than 1000 g, 105 (36.5%) of 288 infants experienced IVH. Multivariate analysis revealed that thrombocytopenia [odds ratio (OR) 2.03, 95% confidence interval (CI) 1.30-3.19, P = 0.0020] and cardiopulmonary resuscitation (CPR) ± intubation at delivery (OR 1.84, 95% CI 1.12-3.02, P = 0.0162) were independently associated with IVH. Among infants less than 1000 g, thrombocytopenia (OR 2.09, 95% CI 1.22-3.60, P = 0.0077) and CPR ± intubation at delivery (OR 2.01, 95% CI 1.10-3.68, P = 0.0229) were also significantly associated with IVH. IVH is a complex phenomenon with many contributing risk factors. In our study, infants less than 30-week gestational age and less than 1000 g revealed thrombocytopenia and CPR ± intubation in delivery room were independently associated with IVH. These data should alert clinicians to those neonates most likely to suffer IVH.

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.

The Consequences of Preterm Birth and Chorioamnionitis on Brainstem Respiratory Centers: Implications for Neurochemical Development and Altered Functions by Inflammation and Prostaglandins

Preterm birth is a major cause for neonatal morbidity and mortality, and is frequently associated with adverse neurological outcomes. The transition from intrauterine to extrauterine life at birth is particularly challenging for preterm infants. The main physiological driver for extrauterine transition is the establishment of spontaneous breathing. However, preterm infants have difficulty clearing lung liquid, have insufficient surfactant levels, and underdeveloped lungs. Further, preterm infants have an underdeveloped brainstem, resulting in reduced respiratory drive. These factors facilitate the increased requirement for respiratory support. A principal cause of preterm birth is intrauterine infection/inflammation (chorioamnionitis), and infants with chorioamnionitis have an increased risk and severity of neurological damage, but also demonstrate impaired autoresuscitation capacity and prevalent apnoeic episodes. The brainstem contains vital respiratory centers which provide the neural drive for breathing, but the impact of preterm birth and/or chorioamnionitis on this brain region is not well understood. The aim of this review is to provide an overview of the role and function of the brainstem respiratory centers, and to highlight the proposed mechanisms of how preterm birth and chorioamnionitis may affect central respiratory functions.

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.

Urinary Levels of IL-1β and GDNF in Preterm Neonates as Potential Biomarkers of Motor Development: A Prospective Study

Objectives. To evaluate the association between inflammatory biomarkers, neurotrophic factors, birth conditions, and the presence of motor development abnormalities in preterm neonates. Methods. Plasma and urinary levels of cytokines (IL-1β, IL-6, IL-10, TNF, and IL-12p70), chemokines (CXCL8/IL-8, CCL2/MCP-1, CCL5/RANTES, CXCL10/IP-10, and CXCL9/MIG), and neurotrophic factors (BDNF and GDNF) were evaluated in 40 preterm neonates born between 28 and 32 incomplete weeks of gestation, at four distinct time points: at birth (umbilical cord blood) (T0), at 48 (T1), at 72 hours (T2), and at 3 weeks after birth (T3). Biomarkers levels were compared between different time points and then associated with Test of Infant Motor Performance (TIMP) percentiles. Results. Maternal age, plasma, and urinary concentrations of inflammatory molecules and neurotrophic factors were significantly different between groups with normal versus lower than expected motor development. Higher levels of GDNF were found in the group with lower than expected motor development, while IL-1β and CXCL8/IL-8 values were higher in the group with typical motor development. Conclusion. Measurements of cytokines and neurotrophic factors in spot urine may be useful in the follow-up of motor development in preterm neonates.

Measurement of interleukin-6 (IL-6) and erythropoietin (EPO) in umbilical cords of preterm infants with intraventricular hemorrhage in two hospitals in Tehran

BACKGROUND

Intraventricular hemorrhage (IVH) is an important cause of death in premature infants. This study aimed to assess the association of the umbilical cord plasma levels of interleukin-6 (IL-6) and erythropoietin (EPO) with the occurrence and severity of IVH in premature infants.

METHODS

Fifty premature newborns of mothers with chorioamnionitis risk factor were selected via nonprobability sampling. The concentration of the cord plasma's IL-6 and erythropoietin were measured by enzyme-linked immunosorbent assay (ELISA) for 3 days. Finally, all samples underwent sonography for the diagnosis of IVH. Results analyzed statistically.

RESULTS

Among the samples, 68.98% of them were diagnosed with IVH grade 1. The most severe IVH cases were detected on the second day. The mean and standard deviation of IL-6 level was 74.71 ± 50.53 in the case group and 24.10 ± 46.10 in the control group. There was a correlation between IL-6 levels and IVH (p = 0.0005). The mean and standard deviation of EPO level was 18.38 ± 15.23 in the IVH group and 6.45 ± 13.48 in samples without IVH. A correlation was detected between EPO level and IVH (p = 0.005).

CONCLUSION

The concentration of IL-6 and EPO levels of the cord plasma was higher in the premature newborns with IVH.

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

Proinflammatory cytokines are essential mediators and indicators of an inflammatory process occurring in the body. Their physiological role is to stimulate the immune response, yet their excessive propagation and interaction with cells outside the immune system may be linked to the risk of organ damage. This is specifically important in the case of immature tissues of fetuses and prematurely born infants. Analysis of the concentrations of specific cytokines in different compartments makes it possible to assess the risk of premature birth, preterm rupture of the membranes, and to determine an existing intrauterine infection. The purpose of this paper is to summarize the existing research concerning the relationships between the concentrations of specific proinflammatory cytokines in different compartments (maternal blood serum, amniotic fluid, umbilical cord blood, arterial and venous blood, and cerebrospinal fluid of the newborn) and the risk of intraventricular hemorrhage (IVH) and the degree of its severity. The paper takes also into account the assessment of the usefulness of cytokines as biomarkers for IVH and its complications (posthemorrhagic hydrocephalus, white matter injury).

Peri-intraventricular hemorrhage and oxidative and inflammatory stress markers in very-low birth weight newborns

OBJECTIVES

To evaluate the association between oxidative and inflammatory stress markers with peri-intraventricular hemorrhage (PIVH) in very-low birth weight newborns.

METHODS

This was a prospective study conducted in a level III neonatal unit. Basal and stimulated reactive oxygen intermediates (ROIs), reduced glutathione (GSH), and interleukin-6 (IL-6) levels were measured in umbilical cord blood. Newborns underwent serial ultrasound at the bedside, at 6, 12, 24, and 72hours of life and at seven days for the diagnosis of PIVH, classified as grades I to IV. Two groups were assessed, those with and without PIVH; maternal and neonatal control variables were used for comparison. Univariate and multiple regression analyses were applied.

RESULTS

A total of 125 newborns were assessed. PIVH incidence rate was 12.0%. In the univariate analysis, basal ROI, the use of two or more doses of corticosteroids, birth weight<1,000g, ventilatory support use, and SNAPPE II value ≥ 22 were significantly associated with PIVH. However, in the multivariate analysis, only antenatal steroid use was independently associated with the disease (OR 0,194; 95% CI: 0,048 to 0,773; p=0,02).

CONCLUSION

ROI, GSH, and IL-6 levels were not associated with the occurrence of PIVH in very-low birth weight infants.

Prematurity: present and future

The study of preterm labor and prematurity has undergone a major transformation in its approach from an inevitable part of obstetrics with few answers to one in which science has led to knowledge and clinical intervention. Despite these advancements, understanding of preterm labor and prevention of prematurity is still limited. In the current review, we begin the discussion with fetal viability, first from a historical perspective and then from the understanding of this issue from a prospective of various professional organizations. We then present the scope of the problem of preterm birth from various countries including the discrepancy between the US and Europe. We continue with updates on extreme prematurity and outcomes with two longitudinal studies from the past 2 years. We further review available interventions for prematurity and discuss the use of antenatal corticosteroids. First, we examine their use in the context of professional recommendations and then examine the trajectory of their continued use in the late preterm period. We focus on a European-based trial with preliminary results and an ongoing American counterpart. The current knowledge of molecular mechanisms behind preterm labor is presented with a focus on the multiple etiologies of preterm labor, both known and presumed, with updates in the basic science realm. Furthermore, we present up-to-date studies on prediction of preterm birth and prematurity-related morbidity.

A "multi-hit" model of neonatal white matter injury: cumulative contributions of chronic placental inflammation, acute fetal inflammation and postnatal inflammatory events

OBJECTIVE

We sought to determine whether cumulative evidence of perinatal inflammation was associated with increased risk in a "multi-hit" model of neonatal white matter injury (WMI).

METHODS

This retrospective cohort study included very preterm (gestational ages at delivery <32 weeks) live-born singleton neonates delivered at Hutzel Women's Hospital, Detroit, MI, from 2006 to 2011. Four pathologists blinded to clinical diagnoses and outcomes performed histological examinations according to standardized protocols. Neurosonography was obtained per routine clinical care. The primary indicator of WMI was ventriculomegaly (VE). Neonatal inflammation-initiating illnesses included bacteremia, surgical necrotizing enterocolitis, other infections, and those requiring mechanical ventilation.

RESULTS

A total of 425 live-born singleton neonates delivered before the 32nd week of gestation were included. Newborns delivered of pregnancies affected by chronic chorioamnionitis who had histologic evidence of an acute fetal inflammatory response were at increased risk of VE, unlike those without funisitis, relative to referent newborns without either condition, adjusting for gestational age [odds ratio (OR) 4.7; 95% confidence interval (CI) 1.4-15.8 vs. OR 1.3; 95% CI 0.7-2.6]. Similarly, newborns with funisitis who developed neonatal inflammation-initiating illness were at increased risk of VE, unlike those who did not develop such illness, compared to the referent group without either condition [OR 3.6 (95% CI 1.5-8.3) vs. OR 1.7 (95% CI 0.5-5.5)]. The greater the number of these three types of inflammation documented, the higher the risk of VE (P<0.0001).

CONCLUSION

Chronic placental inflammation, acute fetal inflammation, and neonatal inflammation-initiating illness seem to interact in contributing risk information and/or directly damaging the developing brain of newborns delivered very preterm.

Perinatal biomarkers in prematurity: early identification of neurologic injury

Over the past few decades, biomarkers have become increasingly utilized as non-invasive tools in the early diagnosis and management of various clinical conditions. In perinatal medicine, the improved survival of extremely premature infants who are at high risk for adverse neurologic outcomes has increased the demand for the discovery of biomarkers in detecting and predicting the prognosis of infants with neonatal brain injury. By enabling the clinician to recognize potential brain damage early, biomarkers could allow clinicians to intervene at the early stages of disease, and to monitor the efficacy of those interventions. This review will first examine the potential perinatal biomarkers for neurologic complications of prematurity, specifically, intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL) and posthemorrhagic hydrocephalus (PHH). It will also evaluate knowledge gained from animal models regarding the pathogenesis of perinatal brain injury in prematurity.

Systemic inflammation, intraventricular hemorrhage, and white matter injury

To see if the systemic inflammation profile of 123 infants born before the 28th week of gestation who had intraventricular hemorrhage without white matter injury differed from that of 68 peers who had both lesions, we compared both groups to 677 peers who had neither. Cranial ultrasound scans were read independently by multiple readers until concordance. The concentrations of 25 proteins were measured with multiplex arrays using an electrochemiluminescence system. Infants who had both hemorrhage and white matter injury were more likely than others to have elevated concentrations of C-reactive protein and interleukin 8 on days 1, 7, and 14, and elevated concentrations of serum amyloid A and tumor necrosis factor-α on 2 of these days. Intraventricular hemorrhage should probably be viewed as 2 entities: hemorrhage alone and hemorrhage with white matter injury. Each entity is associated with inflammation, but the combination has a stronger inflammatory signal than hemorrhage alone.

A new way of thinking about complications of prematurity

The morbidity and mortality of preterm infants are impacted by their ability to maintain physiologic homeostasis using metabolic, endocrine, and immunologic mechanisms independent of the mother's placenta. Exploring McEwen's allostatic load model in preterm infants provides a new way to understand the altered physiologic processes associated with frequently occurring complications of prematurity such as bronchopulmonary dysplasia, intraventricular hemorrhage, necrotizing enterocolitis, and retinopathy of prematurity. The purpose of this article is to present a new model to enhance understanding of the altered physiologic processes associated with complications of prematurity. The model of allostatic load and complications of prematurity was derived to explore the relationship between general stress of prematurity and complications of prematurity. The proposed model uses the concepts of general stress of prematurity, allostasis, physiologic response patterns (adaptive-maladaptive), allostatic load, and complications of prematurity. These concepts are defined and theoretical relationships in the proposed model are interpreted using the four maladaptive response patterns of repeated hits, lack of adaptation, prolonged response, and inadequate response. Empirical evidence for cortisol, inflammation, and oxidative stress responses are used to support the theoretical relationships. The proposed model provides a new way of thinking about physiologic dysregulation in preterm infants. The ability to describe and understand complex physiologic mechanisms involved in complications of prematurity is essential for research. Advancing the knowledge of complications of prematurity will advance clinical practice and research and lead to testing of interventions to reduce negative outcomes in preterm infants.

The Th1:th2 dichotomy of pregnancy and preterm labour

Pregnancy is a unique immunological state in which a balance of immune tolerance and suppression is needed to protect the fetus without compromising the mother. It has long been established that a bias from the T helper 1 cytokine profile towards the T helper 2 profile contributes towards successful pregnancy maintenance. The majority of publications that report on aberrant Th1:Th2 balance focus on early pregnancy loss and preeclampsia. Over the last few decades, there has been an increased awareness of the role of infection and inflammation in preterm labour, and the search for new biomarkers to predict preterm labour continues. In this paper, we explore the evidence for an aberrant Th1:Th2 profile associated with preterm labour. We also consider the potential for its use in screening women at high risk of preterm labour and for prophylactic therapeutic measures for the prevention of preterm labour and associated neonatal adverse outcomes.

Causes of adverse pregnancy outcomes and the role of maternal periodontal status - a review of the literature

Preterm (PT) and Low birth weight (LBW) are considered to be the most relevant biological determinants of newborn infants survival, both in developed and in developing countries. Numerous risk factors for PT and LBW have been defined in the literature. Infections of the genitourinary tract infections along with various biological and genetic factors are considered to be the most common etiological factors for PT/LBW deliveries. However, evidence suggests that sub-clinical infection sites that are also distant from the genitor-urinary tract may be an important cause for PT/LBW deliveries. Maternal periodontal status has also been reported by many authors as a possible risk factor for PT and LBW, though not all of the actual data support such hypothesis. The aim of this paper is to review the evidence from various published literature on the association between the maternal periodontal status and adverse pregnancy outcomes. Although this review found a consistent association between periodontitis and PT/LBW, this finding should be treated with great caution until the sources of heterogeneity can be explained.

Cerebral autoregulation in the first day after preterm birth: no evidence of association with systemic inflammation

INTRODUCTION

Both systemic inflammation and impaired cerebral autoregulation (CA) have been associated with brain injury in preterm infants. We hypothesized that impaired CA represents a hemodynamic link between inflammation and brain injury.

RESULTS

Neither fetal vasculitis nor interleukin-6 (IL-6) affected CA significantly. A high level of IL-6 was associated with hypotension (P = 0.03) irrespective of dopamine therapy. The magnitude of impairment in CA increased with decreasing mean arterial blood pressure (MAP) (P = 0.02). No significant associations were found between these parameters and either intraventricular hemorrhage (IVH) (n = 10) or neonatal mortality (n = 8).

DISCUSSION

In conclusion, postnatal inflammation was weakly associated with arterial hypotension, and hypotension was weakly associated with impaired autoregulation. There was no direct association, however, between autoregulation and antenatal or postnatal signs of inflammation.

METHODS

In our study, 60 infants (mean (±SD) of gestational age (GA) 27 (±1.3) wk) underwent continuous recording of MAP and cerebral oxygenation index (OI) by means of near-infrared spectroscopy (NIRS) for 2.3 ± 0.5 h, starting 18 ± 9 h after birth. Coherence and transfer function gain between MAP and OI represented the presence and degree of impairment of CA, respectively. We considered fetal vasculitis (placenta histology) to be an antenatal marker of inflammation, and used the level of IL-6 in blood, measured at 18 ± 10 h after birth, as a postnatal marker of inflammation. Definition of hypotension was MAP (mm Hg) ≤ GA (wk).

Elevated interleukin-6 concentration and alterations of the coagulation system are associated with the development of intraventricular hemorrhage in extremely preterm infants

BACKGROUND

Pathogenesis of intraventricular hemorrhage (IVH) in premature infants is multifactorial. Little is known about the influence of pro-inflammatory cytokine activation on the coagulation system in extremely preterm infants and its impact on the development of IVH.

OBJECTIVE

To determine the interaction between serum interleukin-6 (IL-6) and the coagulation system in preterm infants predisposed to the development of IVH.

METHODS

Vitamin K-dependent coagulation factors were examined retrospectively in 132 extremely preterm infants prior to vitamin K administration at the first day of life. Patients were grouped according to the occurrence of IVH and serum concentration of IL-6 >/<100 pg/ml.

RESULTS

Occurrence of IVH was associated with clinical diagnosis of chorioamnionitis, low gestational age, high CRIB score, air leak, catecholamine treatment, low initial hematocrit and increased serum concentration of IL-6. Infants developing IVH showed a diminished coagulation profile. Multivariable logistic regression analysis revealed decreased activity of coagulation factor VII, development of pneumothorax and low hematocrit as independent risk factors for the development of IVH. An increased IL-6 serum concentration was associated with a significantly decreased activity of coagulation factor VII and increased levels of fibrinogen.

CONCLUSIONS

The association of elevated IL-6 levels with alterations of the coagulation profile and development of IVH found in our study supports the assumption of a close pathophysiological relation between inflammation and IVH.

Functional impairments at school age of preterm born children with late-onset sepsis

BACKGROUND

Late-onset sepsis is a relatively common complication particularly of preterm birth that affects approximately a quarter of very low birth weight infants.

AIM

We aimed to determine the motor, cognitive, and behavioural outcome at school age of preterm children with late-onset sepsis compared to matched controls.

STUDY DESIGN AND SUBJECTS

A prospective case-control study that included preterm infants (gestational age<32weeks and/or birth weight<1500g) admitted to our Neonatal Intensive Care Unit in 2000-2001 with a culture-proven late-onset sepsis, and controls matched for gestational age.

OUTCOME MEASURES

At school age we assessed motor skills, intelligence, visual perception, visuomotor integration, verbal memory, attention, executive functioning, and behaviour.

RESULTS

At 6-9years, 21 of 32 children with late-onset sepsis (68%) had borderline or abnormal motor outcome with most problems in fine motor skills. Their total IQ was 89 compared to 98 in controls. In addition, verbal memory and attention were affected compared to controls (0.61 standard deviations (SD), 95% confidence interval (CI) 0.04-1.17, p=0.033 and 0.94 SD, 95% CI 0.32-1.62, p=0.011, respectively). Multiple episodes of sepsis and gram-negative sepsis were risk factors for worse cognitive outcome.

CONCLUSIONS

At school age, a majority of preterm children with late-onset sepsis had motor problems. Their IQ was considerably lower than matched controls, and memory and attention were specifically impaired. Outcome at school age of preterm children with late-onset sepsis was worse than previously thought.

Cord blood erythropoietin and interleukin-6 for prediction of intraventricular hemorrhage in the preterm neonate

OBJECTIVE

To evaluate cord blood erythropoietin (EPO) and interleukin-6 (IL-6) levels to predict preterm infants at risk of developing intraventricular hemorrhage (IVH).

METHODS

Levels of umbilical cord EPO, acid-base status and IL-6 were analyzed in 116 consecutive, preterm newborns (GA at delivery: 29 [23-34 ] weeks) born to mothers who had a clinically indicated amniocentesis to rule out infection. Early-onset neonatal sepsis (EONS) was diagnosed using symptoms, hematological criteria and blood cultures.

RESULTS

IVH was diagnosed by cranial ultrasounds. The prevalence of IVH in our population was 25% (29/116). There was a direct relationship between cord blood EPO and cord blood IL-6 concentration (r = 0.225, p = 0.014), independent of GA at birth. Elevated cord blood EPO levels (r = 0.182, p = 0.016) and GA at birth (r =  -0.236, p = 0.004) remained significant independent factors associated with the risk of IVH, when evaluated with stepwise logistic regression analyses. Cord blood IL-6, pH, and EONS were not associated with IVH. These relationships remained following correction for GA at birth (p = 0.027).

CONCLUSIONS

Our results suggest that elevation in cord blood EPO may predict newborns at risk for IVH, independent of fetal inflammatory status. Further studies are warranted to confirm this association.

Chemokine CCL18 predicts intraventricular hemorrhage in very preterm infants

BACKGROUND

Intraventricular hemorrhage (IVH) in very preterm infants is a common disease associated with long-term consequences. Risk factors of IVH remain to be further defined.

AIMS

To determine whether specific immunoproteins at birth predict the risk of IVH and whether their receptors are localized at the bleeding site.

METHODS

A prospective cohort consisted of 163 infants born before 32 weeks of gestation. Altogether 107 cord blood immunoproteins and 12 cytokines from peripheral blood obtained 1 and 7 days after birth were analyzed. Serial brain ultrasounds were assessed. Immunohistochemistry of a chemokine receptor from 14 autopsies was studied.

RESULTS

Low levels of cord chemokine CCL18 (chemokine (C-C motif) ligand 18) robustly predicted the risk of IVH grade II-IV when ante- and neonatal risk factors were considered. Cord CCL18 increased from 32 weeks to term. During the first week after very preterm birth CCL18 increased as the risk of new IVH cases decreased. CCL18 receptor, CCR3, was detectable in choroid plexus, periventricular capillary endothelium, ependymal cells, and in germinal matrix.

CONCLUSION

Low cord blood CCL18 is an independent risk factor of IVH. CCL18 may inhibit signal transduction of its receptor in periventricular cells. Defining the function and regulation of CCL18 may help to decrease the risk of IVH.

Maternal serum interleukin-6, C-reactive protein, and matrix metalloproteinase-9 concentrations as risk factors for preterm birth <32 weeks and adverse neonatal outcomes

Elevated concentrations of interleukin-6 (IL-6), C-reactive protein (CRP), and matrix metalloproteinase-9 (MMP-9) in fetal and neonatal compartments have been associated with an increased risk for preterm birth (PTB) and/or neonatal morbidity. The purpose of this study was to determine if the maternal serum concentration of IL-6, CRP, and MMP-9 in women at risk for PTB, who are not in labor and have intact membranes, are associated with an increased risk for PTB <32 weeks and/or neonatal morbidity. Maternal serum samples collected from 475 patients enrolled in a multicenter randomized controlled trial of single versus weekly corticosteroids for women at increased risk for preterm delivery were assayed. Serum was collected at randomization (24 to 32 weeks' gestation). Maternal serum concentrations of IL-6, CRP, and MMP-9 were subsequently determined using enzyme-linked immunoassays. Multivariate logistic regression analysis was performed to explore the relationship between maternal serum concentrations of IL-6, CRP, and MMP-9 and PTB <32 weeks, respiratory distress syndrome (RDS), chronic lung disease (CLD), intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), and any sepsis. Maternal serum concentrations of IL-6 and CRP, but not MMP-9, above the 90th percentile at the time of randomization were associated with PTB <32 weeks. In contrast, there was no significant relationship between RDS and NEC and the maternal serum concentration of IL-6, CRP, or MMP-9 (univariate analysis). The development of CLD was associated with a high (above 90th percentile) IL-6 and CRP in maternal serum, even after adjustment for gestational age (GA) at randomization and treatment group. However, when GA at delivery was added to the model, this finding was nonsignificant. Neonatal sepsis was more frequent in neonates born to mothers with a high maternal serum concentration of CRP (>90th percentile). However, there was no significant association after adjustment for GA at randomization and treatment group. Logistic regression analysis for each analyte indicated that high maternal serum concentrations of IL-6 and CRP, but not MMP-9, were associated with an increased risk of IVH (odds ratio [OR] 4.60, 95% confidence interval [CI] 1.86 to 10.68; OR 4.07, 95% CI 1.63 to 9.50) after adjusting for GA at randomization and treatment group. Most babies (25/30) had grade I IVH. When GA at delivery was included, elevated IL-6 remained significantly associated with IVH (OR 2.77, 95% CI 1.02 to 7.09). An elevated maternal serum concentration of IL-6 and CRP are risk factors for PTB <32 weeks and subsequent development of neonatal IVH. An elevated maternal serum IL-6 appears to confer additional risk for IVH even after adjusting for GA at delivery.

Cytokine profiles of seventeen cytokines, growth factors and chemokines in cord blood and its relation to perinatal clinical findings

Few papers have investigated the cytokine profiles of multiple cytokines in cord blood. We obtained cord blood samples from 224 infants admitted to our neonatal intensive care unit. Cytokine profiles of 17 cytokines were investigated using cytometric bead array technology. We found a wide variety of cytokines of various levels which ranged from 0.59pg/ml (in Interleukin (IL)-4) to 222.0pg/ml (in macrophage inflammatory protein-1beta. Pro-inflammatory cytokines were highly correlated with each other and with granulocyte-colony stimulating factor and IL-8. On the contrary, IL-5, IL-13, and IL-17 did not show any significant correlation with other cytokines. Several maternal factors were strongly related to several cytokines in cord blood. IL-6, IL-8 and monocyte chemotactic protein-1 were closely related to certain neonatal diseases in preterm neonates. Some cytokines may be regulated independently of each other, while others appear to work as a network affecting physiological and pathological conditions in the fetus.

Integrated review of cytokines in maternal, cord, and newborn blood: part II-- associations with early infection and increased risk of neurologic damage in preterm infants

A growing body of literature supports the relationship of maternal inflammation with preterm birth and adverse neonatal outcomes, including infection and central nervous system (CNS) dysfunction. Mediators of inflammation, most notably proinflammatory cytokines, have been implicated as having an association with and perhaps playing a causal role in the pathogenesis, leading to adverse neonatal outcomes. Even though the association of cytokines with early adverse neonatal outcomes has been actively pursued as a line of research, there has been little integration of diverse findings across studies. Therefore, the purpose of this systematic review was to appraise and classify empirical evidence from human studies for the association of cytokine levels in blood (serum, plasma, or cells; maternal, cord, or neonatal) with two adverse early outcomes in preterm infants: early infection and increased risk of neurologic damage. The review revealed that the proinflammatory cytokines most frequently linked with sepsis are in the interleukin (IL) 1 family as well as tumor necrosis factor alpha (TNF-alpha) and IL-6. The proinflammatory cytokines most frequently linked to neurologic insult in the reviewed studies were IL-1beta, IL-6, and IL-8. In all cases where IL-1beta was studied, the levels were increased when there was neurologic insult. A better understanding of the relationship of these inflammatory substances with these adverse conditions is needed for the future development of maternal and neonatal biobehavioral nursing research.

Intrauterine endotoxin administration leads to white matter diffusivity changes in newborn rabbits

Maternal intrauterine inflammation has been implicated in the development of periventricular leukomalacia and white matter injury in the neonate. We hypothesized that intrauterine endotoxin administration would lead to microstructural changes in the neonatal rabbit white matter in vivo that could be detected at birth using diffusion tensor magnetic resonance imaging (MRI). Term newborn rabbit kits (gestational age 31 days) born to dams exposed to saline or endotoxin in utero on gestational day 28 underwent diffusion tensor imaging, and brain sections were stained for microglia. Comparison between normal and endotoxin groups showed significant decreases in both fractional anisotropy and eigenvalue (e(1)) in all periventricular white matter regions that showed an increase in the number of activated microglial cells, indicating that after maternal inflammation, microglial infiltration may predominantly explain this change in diffusivity in the immediate neonatal period. Diffusion tensor imaging may be a clinically useful tool for detecting neuroinflammation induced by maternal infection in neonatal white matter.

Interleukin-6 -174 and -572 genotypes and the volume of deep gray matter in preterm infants

Preterm infants have smaller cerebral and cerebellar volumes at term compared with term born infants. Perinatal factors leading to the reduction in volumes are not well known. IL-6 -174 and -572 genotypes partly regulate individual immunologic responses and have also been connected with deviant neurologic development in preterm infants. Our hypothesis was that IL-6 -174 and -572 genetic polymorphisms are associated with brain lesions and regional brain volumes in very low birth weight or in very preterm infants. DNA was genotyped for IL-6 -174 and -572 polymorphisms (GG/GC/CC). Study infants (n = 175) were categorized into three groups according to the most pathologic brain finding in ultrasound examinations until term. The brain MRI performed at term was analyzed for regional brain volumes. Analyzed IL-6 genotypes did not show statistically significant association with structural brain lesions. However, IL-6 -174 CC and -572 GG genotypes associated with reduced volume of one brain region, the combined volume of basal ganglia and thalami, both in univariate and in multivariate analyses (p = 0.009, 0.009, respectively). The association of IL-6 -174 and -572 genetic polymorphisms with smaller volumes in deep gray matter provides us new ways to understand the processes leading to neurologic impairments in preterm infants.

Cytokines and perinatal brain damage

Perinatal brain damage has been implicated in the pathogenesis of neurodevelopmental impairments and psychiatric illnesses. This article reviews evidence that infection outside of the brain can damage the brain, and discusses specific cytokines and pathomechanisms that probably mediate the putative effect of remote infection on the developing brain. Events associated with increased circulating inflammatory cytokines, chemokines, and immune cells are described. Finally, studies of genetic variation in susceptibility to cytokine-related brain damage are reviewed.

The diagnosis, management, and postnatal prevention of intraventricular hemorrhage in the preterm neonate

Intraventricular hemorrhage (IVH) occurs in 20% to 25% of very low birthweight preterm neonates and may be associated with significant sequelae. Infants who have IVH are at risk for posthemorrhagic hydrocephalus and periventricular leukomalacia; as many as 75% of those who have parenchymal involvement of hemorrhage suffer significant neurodevelopmental disability. Because of the prevalence of IVH and the medical and societal impact of this disease, many postnatal pharmacologic prevention strategies have been explored. Randomized clinical prevention trials should provide long-term neurodevelopmental follow-up to assess the impact of preterm birth, injury, and pharmacologic intervention on the developing brain.

Intrauterine administration of endotoxin leads to motor deficits in a rabbit model: a link between prenatal infection and cerebral palsy

OBJECTIVE

This study was undertaken to determine whether maternal intrauterine endotoxin administration leads to neurobehavioral deficits in newborn rabbits.

STUDY DESIGN

Pregnant New Zealand white rabbits were injected with 1 mL saline solution (n = 8) or 20 microg/kg of lipopolysaccharide in saline solution (n = 8) into the uterine wall on day 28/31 of gestation. On postnatal day 1, kits (saline solution [n = 30] and lipolysaccharide in saline solution [n = 18] from 4 consecutive litters) underwent neurobehavioral testing. Neonatal brains were stained for microglial cells and myelin.

RESULTS

Kits in the lipopolysaccharide in saline solution group were hypertonic and demonstrated significant impairment in posture, righting reflex, locomotion, and feeding, along with neuroinflammation indicated by activated microglia and hypomyelination in the periventricular regions. A greater mortality was noted in the lipopolysaccharide in saline solution group (16 stillbirths from 3 litters vs 3 from 1 litter).

CONCLUSION

Maternal intrauterine endotoxin administration leads to white matter injury and motor deficits in the newborn rabbit, resulting in a phenotype that resembles those found in periventricular leukomalacia and cerebral palsy.

Histological inflammatory responses in the placenta and early neonatal brain injury

We investigated the relationship between the severity of histological inflammatory responses in the placenta, chorionic plate, and umbilical cord in conjunction with the intraventricular hemorrhage (IVH) risk in premature infants. Clinical data were prospectively collected for 287 consecutive premature neonates born before 32 completed weeks of gestation and admitted to the level III neonatal intensive care unit of the Department of Pediatrics at Padua University from January 1999 to December 2004. Placental histology for histological chorioamnionitis (HCA) was graded and scored according to Redline and others. The diagnosis of IVH (grades I-IV) was graded according to Volpe's classification. Among the placentas of the 287 preterm examined infants, 68 (23.6%) were diagnosed with acute HCA. Overall incidence of IVH was 11.8%. Of 68 preterm neonates with HCA, 11 developed IVH (16.1%). Maternal HCA at the higher grades and stages increased the risk of IVH: 7 (64%) of the 11 preterm infants with maternal HCA grade 3 developed IVH (RR; 95% CI 2.05; 1.1-3.6) and 8 (73%) of the 11 preterm neonates with stage 3 developed IVH (RR; 95% CI 1.59; 1.0-2.5). Conversely, fetal inflammation was not associated with an increased risk of IVH. In conclusion, the IVH risk in preterm infants at less than 32 gestation weeks is significantly associated with severe grade and stage maternal HCA inflammatory scores.

Interleukin-6 polymorphism is associated with chorioamnionitis and neonatal infections in preterm infants

OBJECTIVES

To evaluate whether genotypes of interleukin (IL)-6 gene promoter positions -174 and -572 are associated with histologic chorioamnionitis and neonatal inflammatory disease in preterm infants.

STUDY DESIGN

DNA from very low birth weight or very preterm infants (n = 107) was genotyped for IL-6-174 and -572 polymorphisms (GG/GC/CC). The placentas were analyzed for histological inflammatory findings. Data on neonatal inflammatory diseases, including chronic lung disease (CLD), necrotizing enterocolitis (NEC), and septicemia, were collected using the definitions of the Vermont Oxford Network database.

RESULTS

In univariate analyses, the IL-6-174 GG genotype was associated with a higher incidence of histologic chorioamnionitis. In multivariate analyses, the -174 GG and -572 GC genotypes were correlated with histologic chorioamnionitis (P = .039 and .009, respectively). Gestational age was not associated with genotype polymorphisms. IL-6-174 genotypes were not associated with CLD and/or NEC, but the CC genotype was correlated with septicemia in both univariate and multivariate analyses (P = .027). IL-6-572 genotypes were not associated with neonatal inflammatory disease.

CONCLUSIONS

The IL-6-174 GG and -572 GC genotypes were associated with a higher incidence of histologic chorioamnionitis, and the IL-6-174 CC genotype was associated with septicemia in preterm infants. These findings suggest that the genetic composition of the IL-6 promoter area plays a significant role in the pathogenesis of chorioamnionitis and neonatal infections.

Interdisciplinary surveillance of intraventricular haemorrhage associated conditions in infants <1000 g

AIM

Intraventricular haemorrhage (IVH) causes some of the most adverse outcomes in infants with birthweight <1000 g. Incomplete antenatal steroids, acidosis, inflammation, postnatal transfer, delayed surfactant administration, hypothermia, hypotension, hypocapnia, persistent ductus arteriosus and pneumothorax are all associated with IVH. We hypothesized that prospective surveillance of these IVH-associated conditions decreases their frequency and thus the frequency of IVH.

METHODS

Cranial ultrasound was performed on days 1, 3, 7, 30 after birth and at discharge, and was assessed according to Papile. The incidence of IVH and IVH-associated conditions was monitored prospectively in all infants <1000 g born in our perinatal centre in 2005/2006, and obstetricians and neonatologists held monthly interdisciplinary review conferences to discuss the preventability of IVH-associated conditions (IVH surveillance). These data were compared to existing prospective data gathered during routine monitoring in 2004.

RESULTS

IVH (all grades) occurred in 29/86 extremely low birthweight (ELBW) infants during routine monitoring and in 12/89 ELBW infants during IVH surveillance (p = 0.007). IVH grades 3-4 dropped from 20% to 3.4% (p = 0.0006). There were significant differences in completeness of antenatal steroids (54% vs. 67%, p = 0.04) and timeliness in initial surfactant substitution (45% vs. 71%, p = 0.01). Most other IVH-associated conditions were reduced during IVH surveillance without reaching significance.

CONCLUSIONS

IVH is not always an inevitable disaster. Obstetricians and neonatologists can reduce its incidence by joint prospective surveillance of IVH-associated conditions.

Assessment of serum interleukin-6 with a rapid test. The diagnosis of neonatal sepsis can be established or ruled out

Bevezetés: A neonatális szepszis mortalitása magas, és koraszülöttek esetén a szepszis rizikója emelkedik a születési súly csökkenésével. Anyag és módszer: A szerzők gyorsteszt segítségével 12 érett újszülött és 60 igen kis súlyú (VLBW) koraszülött interleukin-6-vérszintjét határozták meg a C-reaktív protein vizsgálatával egyidejűleg, akiket a Semmelweis Egyetem I. Számú Szülészeti és Nőgyógyászati Klinikájának Neonatális Intenzív Centrumában kezeltek 2005-ben és 2006-ban. A szérum-IL-6 meghatározása gyorsteszt segítségével történt (Milenia Quickline IL-6, PicoScan system). Eredmények: Vizsgálataikban a szérum-interleukin-6- és CRP-meghatározás korrelált. A szérum-IL-6-meghatározás szenzitivitása a CRP-értékkel együtt az általuk vizsgált betegcsoportban 100% volt, álnegatív eset nem fordult elő. A vizsgálat pozitív prediktív értéke 93%. Adataikat Mann–Whitney-teszt segítségével analizálták (SPSS Statistical Software Package, Chicago, IL, USA). Szignifikáns különbség volt az igazolt szepszis és az infekciós betegcsoport IL-6-értékei között ( p = 0,048), valamint az infekciós és nem infekciós csoport interleukin-6-értékei között ( p < 0,005). Következtetések: Az igen kis súlyúak nem specifikus infekciós tünetekhez hasonló reakcióit értékelve, a szeptikus és nem infekciós esetek elkülönítése a neonatális morbiditás és mortalitás csökkentése érdekében is fontos szempont, a költségek csökkentésével egyidejűleg.

Interleukin-6 upregulates expression of KDR and stimulates proliferation of human cerebrovascular smooth muscle cells

Interleukin-6 (IL-6) may play multiple roles in angiogenesis and vascular remodeling. Our previous study showed that a promoter polymorphism (174G>C) in IL-6 is associated with brain arteriovenous malformation hemorrhage; tissue expression is related to genotype. In this study, we investigated the effects of IL-6 on human cerebral smooth muscle cells (HCSMCs) and smooth muscle cells isolated from brain arteriovenous malformation surgical specimens (AVM SMCs) and surgical controls (control HCSMCs--from structurally normal temporal lobe taken during surgical treatment of epilepsy patients). We found that IL-6 (1.1+/-0.27 versus 0.37+/-0.04 pg/mL, n=5, P<0.05) and endogenous vascular endothelial growth factor (VEGF) receptor II (kinase domain-containing receptor (KDR), 15+/-3 versus 1.5+/-3 pg/mL, n=5, P<0.05) were increased in brain AVM SMCs compared with control HCSMCs. Further research revealed that IL-6 could stimulate SMC proliferation, VEGF release, and KDR activation in control HCSMCs. It could also stimulate KDR phosphorylation in control HCSMCs, further confirming a unique role of IL-6 in the triggering of KDR. Interleukin-6 could increase matrix metalloproteinase-9 (MMP-9) secretion through activating KDR in control HCSMCs (P<0.05 versus control). Inhibiting IL-6-induced KDR could reduce MMP-9 activity at least 50% compared with the control group (P<0.05). Increased MMP-9 activity was accompanied by increased control HCSMC proliferation, and blocking MMP-9 activity significantly reduced IL-6-induced control HCSMC proliferation (P<0.05). Collectively, our results show that IL-6 could activate, amplify, and maintain the angiogenic cascade in HCSMCs. A novel role of IL-6 during HCSMC proliferation is upregulating KDR expression and phosphorylation. The results may contribute to the angiogenic phenotype of human brain vascular diseases, such as brain AVM.