Association of preterm birth with sustained postnatal inflammatory response

The protective effects of naringenin, a citrus flavonoid, non-complexed or complexed with hydroxypropyl-β-cyclodextrin against multiorgan damage caused by neonatal endotoxemia

BACKGROUND

Endotoxemia is a severe and dangerous clinical syndrome that results in elevated morbidity, especially in intensive care units. Neonates are particularly susceptible to endotoxemia due to their immature immune systems. There are few effective treatments for neonatal endotoxemia. One group of compounds with potential in the treatment of neonatal inflammatory diseases such as endotoxemia is the flavonoids, mainly due to their antioxidant and anti-inflammatory properties. Among these, naringenin (NGN) is a citrus flavonoid which has already been reported to have anti-inflammatory, antioxidant, anti-nociceptive and anti-cancer effects. Unfortunately, its clinical application is limited by its low solubility and bioavailability. However, cyclodextrins (CDs) have been widely used to improve the solubility of nonpolar drugs and enhance the bioavailability of these natural products.

OBJECTIVE

We, therefore, aimed to investigate the effects of NGN non-complexed and complexed with hydroxypropyl-β-cyclodextrin (HPβCD) on neonatal endotoxemia injuries in a rodent model and describe the probable molecular mechanisms involved in NGN activities.

METHOD

We used exposure to a bacterial lipopolysaccharide (LPS) to induce neonatal endotoxemia in the mice.

RESULTS

It was found that NGN (100 mg/kg i.p.) exposure during the neonatal period reduced leukocyte migration and decreased pro-inflammatory cytokine (TNF-α, IL-1β and IL-6) levels in the lungs, heart, kidneys or cerebral cortex. In addition, NGN upregulated IL-10 production in the lungs and kidneys of neonate mice. The administration of NGN also enhanced antioxidant enzyme catalase and SOD activity, reduced lipid peroxidation and protein carbonylation and increased the reduced sulfhydryl groups in an organ-dependent manner, attenuating the oxidative damage caused by LPS exposure. NGN decreased ERK1/2, p38MAPK and COX-2 activation in the lungs of neonate mice. Moreover, NGN complexed with HPβCD was able to increase the animal survival rate.

CONCLUSION

NGN attenuated inflammatory and oxidative damage in the lungs, heart and kidneys caused by neonatal endotoxemia through the MAPK signaling pathways regulation. Our results show that NGN has beneficial effects against neonatal endotoxemia and could be useful in the treatment of neonatal inflammatory injuries.

Mortality Risk Factors of Early Neonatal Sepsis During COVID-19 Pandemic

Purpose

This study aimed to determine predisposing factors for negative outcome in infants with early neonatal sepsis during COVID-19.

Patients and Methods

A prospective cohort study of 172 newborns up to 4 days diagnosed with neonatal sepsis was carried out in Karaganda (Kazakhstan). The microbiological examination was used to identify a causative agent of bloodstream infection. ELISA was performed to determine the total anti-SARS-CoV-2 antibodies. Gestational age, mode of delivery, birth weight, C-reactive protein and procalcitonin levels, comorbidities, type of pathogen, duration of hospitalization and mother’s infection diseases were used for statistical analysis.

Results

Mortality in infants with neonatal sepsis was 22% (38/172). Anti-SARS-CoV-2 antibodies were detected in 68.3% of the newborns. Culture-negative ELBW infants have a 5.3-fold higher risk of death (p<0.001). Low gestational age and a shorter period of hospitalization were statistically associated with fatality. CRP is generally higher in deceased children (p=0.002). Necrotizing enterocolitis (p<0.001), pneumonia (p=0.009) and anemia (p=0.016) were significantly associated with negative outcome. And, 31.4% of the infants with sepsis had positive blood cultures. The leading cause of sepsis in newborns was CoNS – 57%.

Conclusion

During COVID-19 pandemic neonatal sepsis mortality was associated with low birth weight, gestational age, and comorbidities as in non-pandemic time. The relationship between COVID-19 in the mother and neonatal mortality was not found. However, anti-SARS-CoV-2 antibodies were detected in more than half of newborns.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

Preterm Birth Is Associated With Immune Dysregulation Which Persists in Infants Exposed to Histologic Chorioamnionitis

Introduction

Preterm infants are at increased risk of exposure to histologic chorioamnionitis (HCA) when compared to term-born controls, and this is associated with several neonatal morbidities involving brain, lungs and gut. Preterm infants could benefit from immunomodulatory therapies in the perinatal period, but development of rational treatment strategies requires improved characterization of the perinatal response to HCA. We had two objectives: The first, to characterize the umbilical cord blood immune profile in preterm infants compared to term-born controls; the second, to investigate the postnatal immune response in preterm infants exposed to HCA versus those who were not.

Population

For objective one 59 term infants [mean gestational age (GA) 39⁺⁴ (37⁺³ to 42⁺⁰)] and 55 preterm infants [mean GA29⁺⁰(23⁺³ to 32⁺⁰)] with umbilical cord samples available were included; for objective two we studied 96 preterm infants [mean GA29⁺¹(23⁺² to 32⁺⁰)] for whom placental histology and postnatal blood samples were available.

Methods

Placental histopathology was used to identify reaction patterns indicative of HCA, and a customized immunoassay of 24 inflammatory markers and trophic proteins selected to reflect the perinatal immune response was performed on umbilical cord blood in term and preterm participants and postnatal day 5 blood in the preterm group.

Results

The umbilical cord blood immune profile classified gestational age category with 86% accuracy (95% CI 0.78-0.92), p-value=1.242x10^-14. Pro-inflammatory proteins IL-6, MCP-1 and CRP were elevated in the cord blood of preterm infants whilst BDNF, C3, C9, IL-18, MMP-9 and RANTES were decreased, compared to infants born at term. In preterm infants, exposure to HCA was associated with elevations in 8 immune proteins on postnatal day 5 (BDNF, C3, C5a, C9, IL-8, MCP-1, MIP-1β and MMP-9) when compared to preterm infants who were not exposed.

Conclusion

Preterm birth is associated with a distinct immune profile in umbilical cord blood and preterm infants exposed to HCA with evidence of a fetal inflammatory response have specific alterations in immune function that are apparent on day 5 of postnatal life.

Neurotrophic Factor Levels in Preterm Infants: A Systematic Review and Meta-Analysis

Objectives: Through a systematic review and meta-analysis of the literature we aimed to compare the levels of BDNF, NGF, NT-3, NT-4, and GDNF between human term and preterm infants, and investigate factors implicated in the variability of effect size estimates. Methods: The analysis was performed in three online databases, MEDLINE Complete, PsycINFO, and CINAHL. A random effects model was used to calculate the standardized mean difference (SMD) of neurotrophic factor levels in preterm infants vs. term within a 95% confidence interval (CI). To explore sources of heterogeneity meta-regression models were implemented. Results: Sixteen studies were included in this meta-analysis. A combined sample of 1,379 preterm and 1,286 term newborns were evaluated. We identified significant lower BDNF (SMD = -0.32; 95% CI: -0.59, -0.06; p = 0.014) and NT-3 (SMD = -0.31; 95% CI: -0.52, -0.09; p = 0.004) levels in preterm compared to term infants. No significant difference was observed in NGF and NT-4 levels between groups. Given that only two effect sizes were generated for GDNF levels, no meta-analytical model was performed. Meta-regression models revealed sample type (placental tissue, cerebrospinal fluid, peripheral blood, and umbilical cord blood) as a significant moderator of heterogeneity for BDNF meta-analysis. No significant associations were found for gestational week, birth weight, and clinical comorbidity of newborns with effect sizes. Conclusions: Our findings indicated that lower BDNF and NT-3 levels may be associated with preterm birth. Future studies with larger samples sizes should investigate neurodevelopmental manifestations resulting from neurotrophic factor dysregulation among preterm infants.

Interleukin-8 dysregulation is implicated in brain dysmaturation following preterm birth

BACKGROUND

Preterm birth is associated with dysconnectivity of structural brain networks, impaired cognition and psychiatric disease. Systemic inflammation contributes to cerebral dysconnectivity, but the immune mediators driving this association are poorly understood. We analysed information from placenta, umbilical cord and neonatal blood, and brain MRI to determine which immune mediators link perinatal systemic inflammation with dysconnectivity of structural brain networks.

METHODS

Participants were 102 preterm infants (mean gestational age 29⁺¹ weeks, range 23⁺³-32⁺⁰). Placental histopathology identified reaction patterns indicative of histologic chorioamnionitis (HCA), and a customized immunoassay of 24 inflammation-associated proteins selected to reflect the neonatal innate and adaptive immune response was performed from umbilical cord (n = 55) and postnatal day 5 blood samples (n = 71). Brain MRI scans were acquired at term-equivalent age (41⁺⁰ weeks [range 38⁺⁰-44⁺⁴ weeks]) and alterations in white matter connectivity were inferred from mean diffusivity and neurite density index across the white matter skeleton.

RESULTS

HCA was associated with elevated concentrations of C5a, C9, CRP, IL-1β, IL-6, IL-8 and MCP-1 in cord blood, and IL-8 concentration predicted HCA with an area under the receiver operator curve of 0.917 (95% CI 0.841 - 0.993, p < 0.001). Fourteen analytes explained 66% of the variance in the postnatal profile (BDNF, C3, C5a, C9, CRP, IL-1β, IL-6, IL-8, IL-18, MCP-1, MIP-1β, MMP-9, RANTES and TNF-α). Of these, IL-8 was associated with altered neurite density index across the white matter skeleton after adjustment for gestational age at birth and at scan (β = 0.221, p = 0.037).

CONCLUSIONS

These findings suggest that IL-8 dysregulation has a role in linking perinatal systemic inflammation and atypical white matter development in preterm infants.

IRAK1 Is a Critical Mediator of Inflammation-Induced Preterm Birth

Preterm birth (PTB) is a major cause of neonatal mortality and morbidity, often triggered by chorioamnionitis or intrauterine inflammation (IUI) with or without infection. Recently, there has been a strong association of IL-1 with PTB. We hypothesized that IL-1R-associated kinase 1 (IRAK1), a key signaling mediator in the TLR/IL-1 pathway, plays a critical role in PTB. In human fetal membranes (FM) collected immediately after birth from women delivering preterm, p-IRAK1 was significantly increased in all the layers of FM with chorioamnionitis, compared with no-chorioamnionitis subjects. In a preterm rhesus macaque model of IUI given intra-amniotic LPS, induction of p-IRAK1 and downstream proinflammatory signaling mediators were seen in the FM. In a C57BL/6J wild-type PTB mouse model of IUI given intrauterine LPS, an IRAK1 inhibitor significantly decreased PTB and increased live birth in a dose-dependent manner. Furthermore, IRAK1 knockout mice were protected from LPS-induced PTB, which was seen in wild-type controls. Activation of IRAK1 was maintained by K63-mediated ubiquitination in preterm FM of humans with chorioamnionitis and rhesus and mouse IUI models. Mechanistically, IRAK1 induced PTB in the mouse model of IUI by upregulating expression of COX-2. Thus, our data from human, rhesus, and mouse demonstrates a critical role IRAK1 in IUI and inflammation-associated PTB and suggest it as potential therapeutic target in IUI-induced PTB.

Tendril extract of Cucurbita moschata suppresses NLRP3 inflammasome activation in murine macrophages and human trophoblast cells

Inflammation is the root cause of many diseases that pose a serious threat to human health. Excessive inflammation can also result in preterm birth or miscarriage in pregnant women. Pumpkin (Cucurbita moschata Duchesne, CMD) is a well-known traditional health food and medicinal herb used in many countries to treat diabetes, obesity, osteoporosis, cancer and other diseases. In this study, we investigated the effects of hot water extract derived from the tendrils of C. moschata Duchesne (TCMD) on NLRP3 inflammasome activation in murine macrophages and human trophoblast cells. The TCMD treatment of LPS-primed bone marrow-derived macrophages (BMDMs) and human trophoblast cells attenuated NLRP3 inflammasome activation induced by inflammasome activators such as ATP, nigericin, and monosodium urate (MSU). TCMD treatment suppressed IL-1β secretion in a dose-dependent manner, without affecting IL-6 secretion. In addition, TCMD inhibited NLRP3-dependent pyroptosis in BMDMs. TCMD also suppressed the release of mature IL-1β and activation of cleaved-caspase-1 via limited ASC oligomerization. Furthermore, TCMD significantly inhibited IL-1β secretion and pyroptotic cell death in human trophoblast cells. These results suggest that TCMD exhibits anti-inflammatory effects mediated via inhibition of NLRP3 inflammasome activation suggesting therapeutic potential against inflammatory diseases, preterm birth, and miscarriage.

Time and dose-dependent impairment of neonatal respiratory motor activity after systemic inflammation

Neonatal respiratory impairment during infection is common, yet its effects on respiratory neural circuitry are not fully understood. We hypothesized that the timing and severity of systemic inflammation is positively correlated with impairment in neonatal respiratory activity. To test this, we evaluated time- and dose-dependent impairment of in vitro fictive respiratory activity. Systemic inflammation (induced by lipopolysaccharide, LPS, 5 mg/kg, i.p.) impaired burst amplitude during the early (1 h) inflammatory response. The greatest impairment in respiratory activity (decreased amplitude, frequency, and increased rhythm disturbances) occurred during the peak (3 h) inflammatory response in brainstem-spinal cord preparations. Surprisingly, isolated medullary respiratory circuitry within rhythmic slices showed decreased baseline frequency and delayed onset of rhythm only after higher systemic inflammation (LPS 10 mg/kg) early in the inflammatory response (1 h), with no impairments at the peak inflammatory response (3 h). Thus, different components of neonatal respiratory circuitry have differential temporal and dose sensitivities to systemic inflammation, creating multiple windows of vulnerability for neonates after systemic inflammation.

Reduced neonatal brain-derived neurotrophic factor is associated with autism spectrum disorders

Mental disorders have for the majority of cases an unknown etiology, but several studies indicate that neurodevelopmental changes happen in utero or early after birth. We performed a nested case-control study of the relation between blood levels of neuro-developmental (S100B, BDNF, and VEGF-A) and inflammatory (MCP-1, TARC, IL-8, IL-18, CRP, and IgA) biomarkers in newborns, and later development of autism spectrum disorders (ASD, N = 751), attention deficit hyperactivity disorders (ADHD, N = 801), schizophrenia (N = 1969), affective (N = 641) or bipolar disorders (N = 641). Samples and controls were obtained as part of the iPSYCH Danish Case-Cohort Study using dried blood spot samples collected between 1981 and 2004, and stored frozen at the Danish National Biobank. In newborns lower blood level of BDNF was significantly associated with increased odds (OR 1.15) of developing ASD (p = 0.001). This difference could not be explained by genetic variation in the BDNF coding gene region. A tendency of decreased levels of all the neurotrophic markers and increased levels of all inflammatory markers was noted. The low newborn blood levels of BDNF in children developing ASD is an important finding, suggesting that lower BDNF levels in newborns contributes to the etiology of ASD and indicates new directions for further research. It may also help identifying a long-sought marker for high-ASD risk in, e.g., younger siblings of ASD children.

Inflammatory mediators of stress exposure and neurodevelopment in very preterm infants: Protocol for the stress neuro-immune study

AIMS

(a) Determine relationships among stress exposure, inflammation, and neurodevelopment in very preterm infants and determine the mediated effect of inflammation on the relationship between stress exposure and neurodevelopment; (b) describe cytokine trajectories following birth and determine the effect of stress exposure on these trajectories; and (c) examine relationships between stress exposure and chronic stress responses in very preterm infants.

DESIGN

Non-experimental, repeated measures.

METHODS

Very preterm infants born 28-31 weeks post menstrual age will be enrolled. Cumulative stress exposure over the first 14 days of life will be measured using the Neonatal Infant Stressor Scale. Blood will be collected weekly for the quantification of cytokines. Neurodevelopment will be assessed using the Neurobehavioral Assessment of the Preterm Infant and hair for quantification of hair cortisol will be collected at 35 weeks post menstrual age. Multiple linear regression and conditional process analysis will be used to analyse the relationships among stress exposure, inflammation and neurodevelopment. Linear mixed models will be used to determine inflammatory trajectories over time. IRB approval for the study was received May 2017, and funding from the National Institute of Nursing Research was awarded July 2017.

DISCUSSION

This study will determine the extent to which inflammation mediates the relationship between stress exposure and neurodevelopment. Interventions to attenuate inflammation in preterm infants may improve outcomes.

IMPACT

Determining the potentially modifiable mediators of stress exposure and neurodevelopment in preterm infants is critical to improving long-term outcomes.

Gestational intermittent hypoxia increases susceptibility to neuroinflammation and alters respiratory motor control in neonatal rats

Sleep disordered breathing (SDB) and obstructive sleep apnea (OSA) during pregnancy are growing health concerns because these conditions are associated with adverse outcomes for newborn infants. SDB/OSA during pregnancy exposes the mother and the fetus to intermittent hypoxia. Direct exposure of adults and neonates to IH causes neuroinflammation and neuronal apoptosis, and exposure to IH during gestation (GIH) causes long-term deficits in offspring respiratory function. However, the role of neuroinflammation in CNS respiratory control centers of GIH offspring has not been investigated. Thus, the goal of this hybrid review/research article is to comprehensively review the available literature both in humans and experimental rodent models of SDB in order to highlight key gaps in knowledge. To begin to address some of these gaps, we also include data demonstrating the consequences of GIH on respiratory rhythm generation and neuroinflammation in CNS respiratory control regions. Pregnant rats were exposed to daily intermittent hypoxia during gestation (G10-G21). Neuroinflammation in brainstem and cervical spinal cord was evaluated in P0-P3 pups that were injected with saline or lipopolysaccharide (LPS; 0.1mg/kg, 3h). In CNS respiratory control centers, we found that GIH attenuated the normal CNS immune response to LPS challenge in a gene-, sex-, and CNS region-specific manner. GIH also altered normal respiratory motor responses to LPS in newborn offspring brainstem-spinal cord preparations. These data underscore the need for further study of the long-term consequences of maternal SDB on the relationship between inflammation and the respiratory control system, in both neonatal and adult offspring.

Lifetime Modulation of the Pain System via Neuroimmune and Neuroendocrine Interactions

Chronic pain is a debilitating condition that still is challenging both clinicians and researchers. Despite intense research, it is still not clear why some individuals develop chronic pain while others do not or how to heal this disease. In this review, we argue for a multisystem approach to understand chronic pain. Pain is not only to be viewed simply as a result of aberrant neuronal activity but also as a result of adverse early-life experiences that impact an individual's endocrine, immune, and nervous systems and changes which in turn program the pain system. First, we give an overview of the ontogeny of the central nervous system, endocrine, and immune systems and their windows of vulnerability. Thereafter, we summarize human and animal findings from our laboratories and others that point to an important role of the endocrine and immune systems in modulating pain sensitivity. Taking "early-life history" into account, together with the past and current immunological and endocrine status of chronic pain patients, is a necessary step to understand chronic pain pathophysiology and assist clinicians in tailoring the best therapeutic approach.

Neonatal Cytokine Profiles Associated With Autism Spectrum Disorder

BACKGROUND

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that can be reliably diagnosed at age 24 months. Immunological phenomena, including skewed cytokine production, have been observed among children with ASD. Little is known about whether immune dysregulation is present before diagnosis of ASD.

METHODS

We examined neonatal blood spots from 214 children with ASD (141 severe, 73 mild/moderate), 62 children with typical development, and 27 children with developmental delay as control subjects who participated in the Childhood Autism Risks from Genetics and the Environment study, a population-based case-control study. Levels of 17 cytokines and chemokines were compared across groups and in relation to developmental and behavioral domains.

RESULTS

Interleukin (IL)-1β and IL-4 were independently associated with ASD compared with typical development, although these relationships varied by ASD symptom intensity. Elevated IL-4 was associated with increased odds of severe ASD (odds ratio [OR] = 1.40, 95% confidence interval [CI], 1.03, 1.91), whereas IL-1β was associated with increased odds of mild/moderate ASD (OR = 3.02, 95% CI, 1.43, 6.38). Additionally, IL-4 was associated with a higher likelihood of severe ASD versus mild/moderate ASD (OR = 1.35, 95% CI, 1.04, 1.75). In male subjects with ASD, IL-4 was negatively associated with nonverbal cognitive ability (β = -3.63, SE = 1.33, p = .04).

CONCLUSIONS

This study is part of a growing effort to identify early biological markers for ASD. We demonstrate that peripheral cytokine profiles at birth are associated with ASD later in childhood and that cytokine profiles vary depending on ASD severity. Cytokines have complex roles in neurodevelopment, and dysregulated levels may be indicative of genetic differences and environmental exposures or their interactions that relate to ASD.

Biomarkers of spontaneous preterm birth: a systematic review of studies using multiplex analysis

OBJECTIVE

Despite decades of research on risk indicators of spontaneous preterm birth (PTB), reliable biomarkers are still not available to screen or diagnose high-risk pregnancies. Several biomarkers in maternal and fetal compartments have been mechanistically linked to PTB, but none of them are reliable predictors of pregnancy outcome. This systematic review was conducted to synthesize the knowledge on PTB biomarkers identified using multiplex analysis.

MATERIALS AND METHODS

Three electronic databases (PubMed, EMBASE and Web of Science) were searched for studies in any language reporting the use of multiplex assays for maternal biomarkers associated with PTB published from January 2005 to March 2014.

RESULTS

Retrieved citations (3631) were screened, and relevant studies (33) were selected for full-text reading. Ten studies were included in the review. Forty-two PTB-related proteins were reported, and RANTES and IL-10 (three studies) followed by MIP-1β, GM-CSF, Eotaxin, and TNF-RI (two studies) were reported more than once in maternal serum. However, results could not be combined due to heterogeneity in type of sample, study population, assay, and analysis methods.

CONCLUSION

By this systematic review, we conclude that multiplex assays are a potential technological advancement for identifying biomarkers of PTB, although no single or combination of biomarkers could be identified to predict PTB risk.

The microbiome during pregnancy and early postnatal life

We are changing our concept that the newborn infant emerges from a sterile environment. In-utero colonization may have major impacts on the developing mammal in terms of development of immunity and metabolism that, with epigenetic modifications, will lead to diseases in later life. In addition, the microbial profile that develops during and after birth depends on mode of delivery, type of feeding (human milk versus formula) and various other environmental factors to which the newborn is exposed. The goal of this review is to clarify that the microbiome in the maternal fetal unit as well as the immediate changes that occur as new microbes are acquired postnatally play major roles in subsequent health and disease. Rapidly developing technologies for multi-omic analyses and systems biology are shifting paradigms in both scientific knowledge and clinical care.

Omega-3 fatty acids modulate neonatal cytokine response to endotoxin

Neonatal immune response is characterized by an uncompensated pro-inflammatory response that can lead to inflammation-related morbidity and increased susceptibility to infection. We investigated the effects of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) pre-treatment on cytokine secretion to low-concentration endotoxin (lipopolysaccharide, LPS) in THP-1 monocytes and neonatal cord blood (CB) from healthy full-term infants. Pre-treatment of THP-1 cells, with either n-3 PUFA at 25 or 100 μM significantly reduced IL-6, IL-10, and IL-12 secretion while DHA, but not EPA, reduced TNF-α response to LPS. DHA inhibition was stronger compared to EPA and effective at the low concentration. The same concentrations of n-3 PUFAs inhibited IL-12 but not IL-10 cytokine response in whole CB from 9 infants pre-treated for 24 h. To assess clinical relevance for acute response to LPS, the effects of low-concentration DHA at 25 μM or 12.5 μM were assessed before and after LPS exposure of isolated CB mononuclear cells from 20 infants for 1 h. When added before or after LPS, physiologic DHA treatment produced significant concentration-dependent inhibition of TNF-α, IL-6, IL-1β, and IL-8 secretion. The results demonstrate prophylactic and therapeutic modulation of neonatal cytokine response to LPS and provide proof-of-concept that low-concentration administration of n-3 PUFA could attenuate or resolve neonatal inflammatory response.

Gestational age, mode of birth and breastmilk feeding all influence acute early childhood gastroenteritis: a record-linkage cohort study

Background

Acute gastroenteritis (AGE) is a leading cause of infectious morbidity in childhood. Clinical studies have implicated caesarean section, early birth and formula feeding in modifying normal gut microbiota development and immune system homeostasis in early life. Rates of early birth and cesarean delivery are also increasing worldwide. This study aimed to investigate the independent and combined associations of the mode and timing of birth and breastmilk feeding with AGE hospitalisations in early childhood.

Methods

Population-based record-linkage study of 893,360 singleton livebirths of at least 33 weeks gestation without major congenital conditions born in hospital, New South Wales, Australia, 2001–2011. Using age at first AGE hospital admission, Cox-regression was used to estimate the associations for gestational age, vaginal birth or caesarean delivery by labour onset and formula-only feeding while adjusting for confounders.

Results

There were 41,274 (4.6 %) children admitted to hospital at least once for AGE and the median age at first admission was 1.4 years. Risk of AGE admission increased with decreasing gestational age (37–38 weeks: 15 % increased risk, 33–36 weeks: 25 %), caesarean section (20 %), planned birth (17 %) and formula-only feeding (18 %). The rate of AGE admission was highest for children who were born preterm by modes of birth other than vaginal birth following the spontaneous onset of labour and who received formula-only at discharge from birth care (62–78 %).

Conclusions

Vaginal birth following spontaneous onset of labour at 39+ weeks gestation with any breastfeeding minimised the risk of gastroenteritis hospitalisation in early childhood. Given increasing trends in early planned birth and caesarean section worldwide, these results provide important information about the impact obstetric interventions may have on the development of the infant gut microbiota and immunity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0591-0) contains supplementary material, which is available to authorized users.

The physiology of fetal membrane weakening and rupture: Insights gained from the determination of physical properties revisited

Rupture of the fetal membranes (FM) is precipitated by stretch forces acting upon biochemically mediated, pre-weakened tissue. Term FM develop a para-cervical weak zone, characterized by collagen remodeling and apoptosis, within which FM rupture is thought to initiate. Preterm FM also have a weak region but are stronger overall than term FM. Inflammation/infection and decidual bleeding/abruption are strongly associated with preterm premature FM rupture (pPROM), but the specific mechanisms causing FM weakening-rupture in pPROM are unknown. There are no animal models for study of FM weakening and rupture. Over a decade ago we developed equipment and methodology to test human FM strength and incorporated it into a FM explant system to create an in-vitro human FM weakening model system. Within this model TNF (modeling inflammation) and Thrombin (modeling bleeding) both weaken human FM with concomitant up regulation of MMP9 and cellular apoptosis, mimicking the characteristics of the spontaneous FM rupture site. The model has been enhanced so that test agents can be applied directionally to the choriodecidual side of the FM explant consistent with the in-vivo situation. With this enhanced system we have demonstrated that the pathways involving inflammation/TNF and bleeding/Thrombin induced FM weakening overlap. Furthermore GM-CSF production was demonstrated to be a critical common intermediate step in both the TNF and the Thrombin induced FM weakening pathways. This model system has also been used to test potential inhibitors of FM weakening and therefore pPROM. The dietary supplement α-lipoic acid and progestogens (P4, MPA and 17α-hydroxyprogesterone) have been shown to inhibit both TNF and Thrombin induced FM weakening. The progestogens act at multiple points by inhibiting both GM-CSF production and GM-CSF action. The use of a combined biomechanical/biochemical in-vitro human FM weakening model system has allowed the pathways of fetal membrane weakening to be delineated, and agents that may be of clinical use in inhibiting these pathways to be tested.

A critical role of interleukin-1 in preterm labor

Preterm birth (PTB) is a leading cause of neonatal mortality and morbidity worldwide, and represents a heavy economic and social burden. Despite its broad etiology, PTB has been firmly linked to inflammatory processes. Pro-inflammatory cytokines are produced in gestational tissues in response to stressors and can prematurely induce uterine activation, which precedes the onset of preterm labor. Of all cytokines implicated, interleukin (IL)-1 has been largely studied, revealing a central role in preterm labor. However, currently approved IL-1-targeting therapies have failed to show expected efficacy in pre-clinical studies of preterm labor. Herein, we (a) summarize animal and human studies in which IL-1 or IL-1-targeting therapeutics are implicated with preterm labor, (b) focus on novel IL-1-targeting therapies and diagnostic tests, and (c) develop the case for commercialization and translation means to hasten their development.

Novel Noncompetitive IL-1 Receptor-Biased Ligand Prevents Infection- and Inflammation-Induced Preterm Birth

Preterm birth (PTB) is firmly linked to inflammation regardless of the presence of infection. Proinflammatory cytokines, including IL-1β, are produced in gestational tissues and can locally upregulate uterine activation proteins. Premature activation of the uterus by inflammation may lead to PTB, and IL-1 has been identified as a key inducer of this condition. However, all currently available IL-1 inhibitors are large molecules that exhibit competitive antagonism properties by inhibiting all IL-1R signaling, including transcription factor NF-κB, which conveys important physiological roles. We hereby demonstrate the efficacy of a small noncompetitive (all-d peptide) IL-1R-biased ligand, termed rytvela (labeled 101.10) in delaying IL-1β-, TLR2-, and TLR4-induced PTB in mice. The 101.10 acts without significant inhibition of NF-κB, and instead selectively inhibits IL-1R downstream stress-associated protein kinases/transcription factor c-jun and Rho GTPase/Rho-associated coiled-coil-containing protein kinase signaling pathways. The 101.10 is effective at decreasing proinflammatory and/or prolabor genes in myometrium tissue and circulating leukocytes in all PTB models independently of NF-κB, undermining NF-κB role in preterm labor. In this work, biased signaling modulation of IL-1R by 101.10 uncovers a novel strategy to prevent PTB without inhibiting NF-κB.

Characteristics of neonates with culture-proven bloodstream infection who have low levels of C-reactive protein (≦10 mg/L)

Background

Elevated C-reactive protein (CRP) level is widely used in clinical practice as a marker to distinguish between neonates with or without sepsis. However, some neonates with bacteremia have a CRP level within the normal range and they are not well characterized.

Methods

All episodes of neonatal culture-proven bloodstream infections (BSIs) between July 2004 and June 2012 were enrolled. Patients characteristics were compared for three CRP groups (low, ≤ 10 mg/L; intermediate, 11–100 mg/L; and high, > 100 mg/L) using the Chi-square test and one-way ANOVA. The sepsis-attributable mortality rates were compared using logistic regression analyses.

Results

Of 986 episodes of neonatal BSI, 247 (25.1 %) had CRP ≤10 mg/L at the onset of clinical sepsis. In the low CRP group, patients had lower gestational age and birth weight, and an earlier occurrence of BSI. Patients with underlying gastrointestinal pathology, renal disorders, cholestasis, and pulmonary hypertension had a non-significant elevated CRP level at the onset of sepsis. In the blood culture of the low CRP group, coagulase-negative staphylococci (CoNS) were relatively more common (55.9 %, p < 0.001) than the other two groups, although one-fourth were infected with gram-negative bacilli (19.0 %), fungi (2.8 %), or polymicrobial pathogens (3.6 %). Of the BSIs with initial low CRP, 29.1 % were treated with inadequate antibiotics, 13.0 % progressed to septic shock, and 5.3 % had infectious complications. The sepsis-attributable mortality rate was lower in the low CRP group (4.9 %) than in the high CRP group (13.6 %).

Conclusions

A considerable proportion of neonatal BSIs had a normal or low initial CRP level (≤10 mg/L), which was more likely to occur in low birth weight or extremely preterm infants, those with earlier onset of sepsis, and those infected with CoNS. Plasma CRP level should not be used to rule out severe culture-proven sepsis or guide the empirical choice of antibiotics.

Neonatal levels of inflammatory markers and later risk of schizophrenia

BACKGROUND

There is a long-standing interest in investigating the impact of early-life immune abnormalities on later onset of psychosis. The aim of this study was to assess inflammatory marker levels in neonatal dried blood spots and their association with later risk of schizophrenia.

METHODS

This nested case-control study included 995 cases and 980 control subjects. Cases were identified using the Danish Psychiatric Central Register. Control subjects of same age and sex were identified using the Danish Civil Registration System. Samples for the identified individuals were retrieved from the Danish Neonatal Screening Biobank. Concentrations of 17 inflammatory markers were measured in eluates from dried blood spots using a bead-based multiplex assay. Incidence rate ratios were calculated using conditional logistic regression. Principal component analysis was used to capture the overall variation in the inflammatory markers' concentrations.

RESULTS

No significant differences were found for any of the analyzed interleukins. We did not find any association with schizophrenia for any of the other examined inflammatory markers.

CONCLUSIONS

Our results suggest that persons who develop schizophrenia do not have higher or lower levels of the examined inflammatory markers at the time of birth. Our findings differ from the studies of maternal inflammatory changes during the antenatal period for which associations with schizophrenia have previously been demonstrated.

Pharmacokinetics, microbial response, and pulmonary outcomes of multidose intravenous azithromycin in preterm infants at risk for Ureaplasma respiratory colonization

The study objectives were to refine the population pharmacokinetics (PK) model, determine microbial clearance, and assess short-term pulmonary outcomes of multiple-dose azithromycin treatment in preterm infants at risk for Ureaplasma respiratory colonization. Fifteen subjects (7 of whom were Ureaplasma positive) received intravenous azithromycin at 20 mg/kg of body weight every 24 h for 3 doses. Azithromycin concentrations were determined in plasma samples obtained up to 168 h post-first dose by using a validated liquid chromatography-tandem mass spectrometry method. Respiratory samples were obtained predose and at three time points post-last dose for Ureaplasma culture, PCR, antibiotic susceptibility testing, and cytokine concentration determinations. Pharmacokinetic data from these 15 subjects as well as 25 additional subjects (who received either a single 10-mg/kg dose [n = 12] or a single 20-mg/kg dose [n = 13]) were analyzed by using a nonlinear mixed-effect population modeling (NONMEM) approach. Pulmonary outcomes were assessed at 36 weeks post-menstrual age and 6 months adjusted age. A 2-compartment model with all PK parameters allometrically scaled on body weight best described the azithromycin pharmacokinetics in preterm neonates. The population pharmacokinetics parameter estimates for clearance, central volume of distribution, intercompartmental clearance, and peripheral volume of distribution were 0.15 liters/h · kg(0.75), 1.88 liters · kg, 1.79 liters/h · kg(0.75), and 13 liters · kg, respectively. The estimated area under the concentration-time curve over 24 h (AUC24)/MIC90 value was ∼ 4 h. All posttreatment cultures were negative, and there were no drug-related adverse events. One Ureaplasma-positive infant died at 4 months of age, but no survivors were hospitalized for respiratory etiologies during the first 6 months (adjusted age). Thus, a 3-day course of 20 mg/kg/day intravenous azithromycin shows preliminary efficacy in eradicating Ureaplasma spp. from the preterm respiratory tract.

Meconium microbiome analysis identifies bacteria correlated with premature birth

Background

Preterm birth is the second leading cause of death in children under the age of five years worldwide, but the etiology of many cases remains enigmatic. The dogma that the fetus resides in a sterile environment is being challenged by recent findings and the question has arisen whether microbes that colonize the fetus may be related to preterm birth. It has been posited that meconium reflects the in-utero microbial environment. In this study, correlations between fetal intestinal bacteria from meconium and gestational age were examined in order to suggest underlying mechanisms that may contribute to preterm birth.

Methods

Meconium from 52 infants ranging in gestational age from 23 to 41 weeks was collected, the DNA extracted, and 16S rRNA analysis performed. Resulting taxa of microbes were correlated to clinical variables and also compared to previous studies of amniotic fluid and other human microbiome niches.

Findings

Increased detection of bacterial 16S rRNA in meconium of infants of <33 weeks gestational age was observed. Approximately 61·1% of reads sequenced were classified to genera that have been reported in amniotic fluid. Gestational age had the largest influence on microbial community structure (R = 0·161; p = 0·029), while mode of delivery (C-section versus vaginal delivery) had an effect as well (R = 0·100; p = 0·044). Enterobacter, Enterococcus, Lactobacillus, Photorhabdus, and Tannerella, were negatively correlated with gestational age and have been reported to incite inflammatory responses, suggesting a causative role in premature birth.

Interpretation

This provides the first evidence to support the hypothesis that the fetal intestinal microbiome derived from swallowed amniotic fluid may be involved in the inflammatory response that leads to premature birth.

Intermittent or sustained systemic inflammation and the preterm brain

Exposure to perinatal infection and inflammation is associated with an increased risk for neonatal brain damage and developmental disabilities. In this integrated mechanism review, we discuss evidence in support of the contention that the preterm newborn is capable of intermittent or sustained systemic inflammation (ISSI), which appears to contribute more to adverse neurodevelopmental outcomes in preterm infants than does shorter duration inflammation.

Maternal infection with Schistosoma japonicum induces a profibrotic response in neonates

The global burden of schistosomiasis is significant, with fibrosis a major associated morbidity and the primary cause of mortality. We have previously shown that schistosomiasis during pregnancy upregulates proinflammatory cytokines in the cord blood. In this study, we extend these findings to include a large panel of fibrosis-associated markers. We developed a multiplex bead-based assay to measure the levels of 35 proteins associated with fibrosis. Cord blood from 109 neonates born to mothers residing in an area of Schistosoma japonicum endemicity was assessed for these molecules. Ten mediators were elevated in the cord blood from schistosome-infected pregnancies, including insulin-like growth factor 1 (IGF-1), tumor growth factor β1 (TGF-β1), connective tissue growth factor (CTGF), procollagen I carboxy-terminal propeptide (PICP), amino-telopeptide of type 1 collagen (ICTP), collagen VI, desmosine, matrix metalloproteinase 2 (MMP-2), tissue inhibitor of metalloproteinases 1 (TIMP-1), and TIMP-4. Many of these were also positively correlated with preterm birth (PICP, ICTP, MMP-2, TGF-β1, desmosine, CTGF, TIMP-1). In addition, birth weight was 168 g lower for infants with detectable levels of CTGF than for those with CTGF levels below the level of detection. Maternal schistosomiasis results in upregulation of fibrosis-associated proteins in the cord blood of the neonate, a subset of which are also associated with adverse birth outcomes. As the first report of fibrosis-associated molecules altered in the newborn of infected mothers, this study has broad implications for the health of the fetus, stretching from gestation to adulthood.

Frank A. Beach award: programming of neuroendocrine function by early-life experience: a critical role for the immune system

Many neuropsychiatric disorders are associated with a strong dysregulation of the immune system, and several have a striking etiology in development as well. Our recent evidence using a rodent model of neonatal Escherichia coli infection has revealed novel insight into the mechanisms underlying cognitive deficits in adulthood, and suggests that the early-life immune history of an individual may be critical to understanding the relative risk of developing later-life mental health disorders in humans. A single neonatal infection programs the function of immune cells within the brain, called microglia, for the life of the rodent such that an adult immune challenge results in exaggerated cytokine production within the brain and associated cognitive deficits. I describe the important role of the immune system, notably microglia, during brain development, and discuss some of the many ways in which immune activation during early brain development can affect the later-life outcomes of neural function, immune function, and cognition.

Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis

BACKGROUND

The relationship between histological chorioamnionitis and haematological and biochemical markers in mothers and infants at delivery, and in infants postnatally, is incompletely characterised. These markers are widely used in the diagnosis of maternal and neonatal infection. Our objective was to investigate the effects of histological chorioamnionitis (HCA) on haematological and biochemical inflammatory markers in mothers and infants at delivery, and in infants post-delivery.

METHODS

Two hundred and forty seven mothers, delivering 325 infants, were recruited at the only tertiary perinatal centre in Western Australia. Placentae were assessed for evidence of HCA using a semi-quantitative scoring system. Maternal high sensitivity C-reactive protein (hsCRP), procalcitonin, and umbilical cord hsCRP, procalcitonin, white cell count and absolute neutrophil count were measured at delivery. In infants where sepsis was clinically suspected, postnatal CRP, white cell count and absolute neutrophil count were measured up to 48 hours of age. The effect of HCA on maternal, cord and neonatal markers was evaluated by multivariable regression analysis.

RESULTS

The median gestational age was 34 weeks and HCA was present in 26 of 247 (10.5%) placentae. Mothers whose pregnancies were complicated by HCA had higher hsCRP (median 26 (range 2-107) versus 5.6 (0-108) mg/L; P<0.001). Histological chorioamnionitis was associated with higher umbilical cord hsCRP (75(th) percentile 2.91 mg/L (range 0-63.9) versus 75(th) percentile 0 mg/L (0-45.6); P<0.001) and procalcitonin (median 0.293 (range 0.05-27.37) versus median 0.064 (range 0.01-5.24) ug/L; P<0.001), with a sustained increase in neonatal absolute neutrophil count (median 4.5 (0.1-26.4)×10(9)/L versus 3.0 (0.1-17.8)×10(9)/L), and CRP up to 48 hours post-partum (median 10 versus 6.5 mg/L) (P<0.05 for each).

CONCLUSION

Histological chorioamnionitis is associated with modest systemic inflammation in maternal and cord blood. These systemic changes may increase postnatally, potentially undermining their utility in the diagnosis of early-onset neonatal infection.

Inflammatory and haematological markers in the maternal, umbilical cord and infant circulation in histological chorioamnionitis

Background

The relationship between histological chorioamnionitis and haematological and biochemical markers in mothers and infants at delivery, and in infants postnatally, is incompletely characterised. These markers are widely used in the diagnosis of maternal and neonatal infection. Our objective was to investigate the effects of histological chorioamnionitis (HCA) on haematological and biochemical inflammatory markers in mothers and infants at delivery, and in infants post-delivery.

Methods

Two hundred and forty seven mothers, delivering 325 infants, were recruited at the only tertiary perinatal centre in Western Australia. Placentae were assessed for evidence of HCA using a semi-quantitative scoring system. Maternal high sensitivity C-reactive protein (hsCRP), procalcitonin, and umbilical cord hsCRP, procalcitonin, white cell count and absolute neutrophil count were measured at delivery. In infants where sepsis was clinically suspected, postnatal CRP, white cell count and absolute neutrophil count were measured up to 48 hours of age. The effect of HCA on maternal, cord and neonatal markers was evaluated by multivariable regression analysis.

Results

The median gestational age was 34 weeks and HCA was present in 26 of 247 (10.5%) placentae. Mothers whose pregnancies were complicated by HCA had higher hsCRP (median 26 (range 2–107) versus 5.6 (0–108) mg/L; P<0.001). Histological chorioamnionitis was associated with higher umbilical cord hsCRP (75^th percentile 2.91 mg/L (range 0–63.9) versus 75^th percentile 0 mg/L (0–45.6); P<0.001) and procalcitonin (median 0.293 (range 0.05–27.37) versus median 0.064 (range 0.01–5.24) ug/L; P<0.001), with a sustained increase in neonatal absolute neutrophil count (median 4.5 (0.1–26.4)×10⁹/L versus 3.0 (0.1–17.8)×10⁹/L), and CRP up to 48 hours post-partum (median 10 versus 6.5 mg/L) (P<0.05 for each).

Conclusion

Histological chorioamnionitis is associated with modest systemic inflammation in maternal and cord blood. These systemic changes may increase postnatally, potentially undermining their utility in the diagnosis of early-onset neonatal infection.

Interleukin-19 in fetal systemic inflammation

OBJECTIVE

The fetal inflammatory response syndrome (FIRS) is considered the fetal counterpart of the systemic inflammatory response syndrome (SIRS), which can be caused by infection and non-infection-related insults. Although the initial response is mediated by pro-inflammatory signals, the control of this response is achieved by anti-inflammatory mediators which are essential for the successful outcome of the affected individual. Interleukin (IL)-19 is capable of stimulating the production of IL-10, a major anti-inflammatory cytokine, and is a potent inducer of the T-helper 2 (Th2) response. The aim of this study was to determine if there is a change in umbilical cord plasma IL-19 and IL-10 concentrations in preterm neonates with and without acute funisitis, the histologic counterpart of FIRS.

METHODS

A case-control study was conducted including 80 preterm neonates born after spontaneous labor. Neonates were classified according to the presence (n = 40) or absence of funisitis (n = 40), which is the pathologic hallmark of FIRS. Neonates in each group were also matched for gestational age. Umbilical cord plasma IL-19 and IL-10 concentrations were determined by ELISA.

RESULTS

1) The median umbilical cord plasma IL-19 concentration was 2.5-fold higher in neonates with funisitis than in those without funisitis (median 87 pg/mL; range 20.6-412.6 pg/mL vs. median 37 pg/mL; range 0-101.7 pg/mL; p < 0.001); 2) newborns with funisitis had a significantly higher median umbilical cord plasma IL-10 concentration than those without funisitis (median 4 pg/mL; range 0-33.5 pg/mL vs. median 2 pg/mL; range 0-13.8 pg/mL; p < 0.001); and 3) the results were similar when we included only patients with funisitis who met the definition of FIRS by umbilical cord plasma IL-6 concentrations ≥ 17.5 pg/mL (p < 0.001).

CONCLUSION

IL-19 and IL-10 are parts of the immunologic response of FIRS. A subset of fetuses with FIRS had high umbilical cord plasma IL-19 concentrations. In utero exposure to high systemic concentrations of IL-19 may reprogram the immune response.

Serum interleukin-1β, interleukin-8 and anti-heat shock 60 Chlamydia trachomatis antibodies as markers of ectopic pregnancy

Anti-Chlamydial trachomatis (anti-CT) responses, particularly anti-heat shock 60 (Hsp60), antibodies confer a higher risk of ectopic pregnancy. With emerging evidence supporting the pivotal role of interleukin-1β (IL-1β) and IL-8 in the immunopathogenesis of CT-specific tubal obstruction, we determined anti-CT Hsp60 antibody reactivity and serum concentrations of IL-1β and IL-8 in failed pregnancies consisting of 30 consecutive ectopic pregnancies and 30 missed abortions, with 32 viable intrauterine pregnancies tested as normal controls. ELISAs were utilised to measure IgA or IgG anti-CT major outer membrane outer protein (MOMP) antibodies, IgG anti-CT Hsp60 antibodies and IL-1β and IL-8. IgG anti-CT Hsp60 antibodies were more prevalent in ectopic pregnancy cases (43.3%, 13/30) than in intrauterine pregnancies (16%, 5/32, p=0.016). All 13 ectopic pregnancy anti-CT Hsp60-positive cases had anti-CT MOMP antibodies. CT-specific antibodies were more frequent in merged ectopic pregnancy and missed abortions cases (35%, 21/60) than in intrauterine pregnancies (16%, p=0.049). The median (range) levels of IL-1β in ectopic pregnancy, missed abortions and normal intrauterine pregnancies were 1.74 (0.2-8.7), 1.14 (0.2-16) and 1.22 (0.2-16.2) pg/ml, respectively (p>0.05, for all). Serum IL-8 levels were comparable amongst groups: ectopic pregnancy (median [range]: 25.1 [18.3-1000]); missed abortions (32.9 [15.39-1000]); and intrauterine pregnancies (25.11 [18.3-1000] pg/ml). Anti-CT antibody-positive ectopic pregnancy had significantly lower IL-1β levels (1.29 [0.2-2.93]) pg/ml than sero-negative ectopic pregnancy cases (2.09 [1.10-8.70]) pg/ml, (p=0.022), but IL-8 did not differ. Our data demonstrate that anti-CT Hsp60 immunity is a predominant feature of ectopic pregnancy. We conclude that neither IL-1β nor IL-8 can be considered markers of failed pregnancy, although lower levels of the former cytokine are associated with CT-related ectopic pregnancy.

A lifespan approach to neuroinflammatory and cognitive disorders: a critical role for glia

Cognitive decline is a common problem of aging. Whereas multiple neural and glial mechanisms may account for these declines, microglial sensitization and/or dystrophy has emerged as a leading culprit in brain aging and dysfunction. However, glial activation is consistently observed in normal brain aging as well, independent of frank neuroinflammation or functional impairment. Such variability suggests the existence of additional vulnerability factors that can impact neuronal-glial interactions and thus overall brain and cognitive health. The goal of this review is to elucidate our working hypothesis that an individual's risk or resilience to neuroinflammatory disorders and poor cognitive aging may critically depend on their early life experience, which can change immune reactivity within the brain for the remainder of the lifespan. For instance, early-life infection in rats can profoundly disrupt memory function in young adulthood, as well as accelerate age-related cognitive decline, both of which are linked to enduring changes in glial function that occur in response to the initial infection. We discuss these findings within the context of the growing literature on the role of immune molecules and neuroimmune crosstalk in normal brain development. We highlight the intrinsic factors (e.g., chemokines, hormones) that regulate microglial development and their colonization of the embryonic and postnatal brain, and the capacity for disruption or "re-programming" of this crucial process by external events (e.g., stress, infection). An impact on glia, which in turn alters neural development, has the capacity to profoundly impact cognitive and mental health function at all stages of life.

Biomarkers of spontaneous preterm birth: an overview of the literature in the last four decades

BACKGROUND

Understanding spontaneous preterm birth ([PTB] < 37 weeks) is difficult due to heterogeneities associated with multitudes of risk factors and pathophysiological pathways. Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late.

OBJECTIVE

Systematic review of literature on PTB biomarkers in the last 40 years to map out the existing knowledge and gaps in understanding PTB biomarkers.

SEARCH STRATEGIES

Five electronic databases were searched for human studies on PTB biomarkers published in any language between 1965 and 2008.

SELECTION CRITERIA

The phenotype of interest for final data extraction was exclusively spontaneous PTB with no rupture of membranes. Data extraction included (a) general characteristics of the study (clinical setting, period, and study design), (b) study/participant characteristics (inclusion and exclusion criteria, race/ethnicity, number of participants, gestational age at sampling, (c) characteristics of the biomarker (type, rationale for its selection, type of biological sample, and assay used, and (d) concentration of biomarkers in cases and controls.

DATA COLLECTION AND ANALYSIS

The search yielded 7255 citations and data were extracted from 217 articles which met our inclusion and exclusion criteria.

MAIN RESULTS

A total of 116 different biomarkers were reported and these were assayed 578 times in the 217 included studies. Over two thirds of the 217 studies were performed on North American or European populations. No reliable biomarkers emerged as a risk predictor of PTB.

CONCLUSIONS

Identifying similar studies on biomarkers for the prediction of PTB was a very challenging task due heterogeneities in study design, sampling issues (types, timing and processing), assay methods, and analyses. Major areas of concern identified in this review include poor phenotype definition, nonideal study designs and poor rationale for biomarker selection and assays and population stratification issues.

Antigen-induced cytokine and chemokine release test for tuberculosis infection using adsorption of stimulated whole blood on filter paper and multiplex analysis

BACKGROUND

In vitro stimulation of whole blood or isolated blood cells with specific antigens is used for several purposes. Immediately following incubation with antigens, samples have to be centrifuged to stop the reactions by remaining cells and the supernatant refrigerated or analysed directly to preserve the analytes of interest, which makes samples difficult to prepare outside laboratories. We have tested whether spotting whole blood on filter paper after activation can be used in one of the tests for Mycobacterium tuberculosis infection (MTI), the QuantiFERON®-TB Gold In Tube test (QFT), where the spotting technique can make it suitable for use in locations without facilities like a centrifuge and a refrigerator.

MATERIALS AND METHODS

Samples from 22 individuals undergoing screening for MTI and 10 healthy controls were incubated, centrifuged and IFN-γ measured by Enzyme-linked immunosorbent assay (ELISA), as described in the kit insert. In parallel, activated blood was spotted on filter paper (Schleicher & Schuell) and dried. The dried blood spot samples were analysed for 21 inflammatory markers with an in-house assay based on Luminex technology.

RESULTS

Our multiplex measurements of inflammatory markers in samples from suspected MTI patients confirmed the IFN-γ findings in the QFT. IL-2, GM-CSF, IL-5, and IL-1β were also found as useful markers for MTI. We were not able to distinguish between active tuberculosis and latent MTI.

CONCLUSION

Applying blood on filter paper after incubation makes in vitro stimulation tests feasible in locations where heat and electricity is unavailable.

Neonatal programming of innate immune function

The early life environment can be crucial in influencing the development of an animal's long-term physiology. There is now much evidence to suggest that perinatal challenges to an animal's immune system will result in changes in adult rat behavior, physiology, and molecular pathways following a single inflammatory event during development caused by the bacterial endotoxin lipopolysaccharide (LPS). In particular, it is now apparent that neonatal LPS administration can influence the adult neuroimmune response to a second LPS challenge through hypothalamic-pituitary-adrenal axis modifications, some of which are caused by alterations in peripheral prostaglandin synthesis. These pronounced changes are accompanied by a variety of alterations in a number of disparate aspects of endocrine physiology, with significant implications for the health and well-being of the adult animal. In this review, we discuss the newly elucidated mechanisms by which neonatal immune challenge can permanently alter an animal's endocrine and metabolic physiology and the implications this has for various disease states.

A Danish National Birth Cohort study of maternal HSV-2 antibodies as a risk factor for schizophrenia in their offspring

BACKGROUND

Several studies have implicated early infections, including maternal infection with herpes simplex virus 2 (HSV-2), as an environmental risk factor for schizophrenia.

METHODS

A case-control study nested within the national Danish birth cohort constituted by the PKU Biobank covering all children born in Denmark since 1981. 602 cases of schizophrenia (ICD-10 F20) were ascertained in the Danish Psychiatric Central Register, covering all in- and out-patient contacts in Denmark, and 602 controls were matched individually on gender, exact date of birth and living in Denmark on the date the case became a case. Incidence rate ratio for schizophrenia was estimated using conditional logistic regression. Main exposure was HSV-2 IgG antibody levels. Confounders and potential interacting factors included family history of mental illness, place of birth and gestational age at time of birth.

RESULTS

Elevated levels of maternal HSV-2 IgG were associated with schizophrenia risk (IRR 1.56; 95% CI 1.17-2.07, p=0.002). This association was not confounded by a maternal or sibling history of psychiatric illness, place of birth, parental age, gestational age, or immigrant status of the parents. However, adjustment for paternal psychiatric history reduced risk slightly (IRR 1.43; 95% CI 1.06-1.92, p=0.02).

CONCLUSIONS

The study replicates an association between maternal HSV-2 IgG levels and schizophrenia risk. Since the confounding by familial risk factors is confined to paternal mental illnesses not belonging to the schizophrenia spectrum, we hypothesize that this confounding may be partly due to other risk factors, e.g., other sexually transmitted infections, rather than reflecting variations in genetic liability to develop schizophrenia.

Biomarkers of epidermal innate immunity in premature and full-term infants

Epidermal innate immunity is a complex process involving a balance of pro- and anti-inflammatory cytokines, structural proteins, and specific antigen presenting cells occurring against a background of neuroendocrine modulators such as cortisol. In this study, a multiplex array system was used to simultaneously determine multiple molecular factors critical for development of epidermal innate immune function from the skin surface of premature and term infants, healthy adults, and vernix caseosa. Samples were analyzed for Keratin 1,10,11, Keratin 6, involucrin, albumin, fibronectin and cortisol, and cytokines IL-1, TNFalpha, IL-6, IL-8, MCP1, IP10, IFNgamma, and IL-1 receptor antagonist. Keratin 1,10,11 was decreased and involucrin was increased in infants versus adults. All infants had elevated IL1alpha and reduced TNFalpha versus adults. IL-6, IL-8, and MCP1 were significantly increased in premature versus term infants and adults. Skin surface cortisol and albumin were significantly elevated in premature infants. The biomarker profile in premature infants was unique with differences in structural proteins, albumin, and cytokines IL-6, IL-1beta, IL-8, and MCP1. The higher infant IL1alpha may be associated with skin barrier maturation. The significant elevations in skin surface cortisol for preterm infants may reflect a neuroendocrine response to the stress of premature birth.

Integrated review of cytokines in maternal, cord, and newborn blood: part I--associations with preterm birth

Preterm birth (PTB; spontaneous delivery prior to 37 weeks gestation) affects one out of eight infants born in the United States and is the most common cause of neonatal morbidity and mortality. Although the pathogenesis of PTB is multifactorial, a growing body of literature supports the hypothesis that one cause of PTB is inflammation in pregnancy. Investigators have implicated mediators of inflammation, most notably proinflammatory cytokines, as being associated with and perhaps a playing a causal role in the pathogenesis of preterm labor and adverse early fetal outcomes. Though researchers have pursued the association of cytokines with preterm labor and subsequent early adverse fetal outcomes as a line of research, there has been little integration of diverse findings across studies. This systematic review appraises the empirical evidence from human studies for the association of levels of cytokines in blood with preterm labor and adverse early fetal outcome to examine the current state of the science in this important area of biobehavioral research. The most consistent finding is that increased levels of proinflammatory cytokines, particularly interleukin (IL) 6, IL-beta1, and tumor necrosis factor alpha (TNF-alpha), are associated with PTB as compared to levels found at term birth. However, there have been relatively few studies and results have not been consistent. Therefore, further research is needed to elucidate the association of these inflammatory mediators with adverse pregnancy outcomes.

Early-life programming of later-life brain and behavior: a critical role for the immune system

The immune system is well characterized for its critical role in host defense. Far beyond this limited role however, there is mounting evidence for the vital role the immune system plays within the brain, in both normal, “homeostatic” processes (e.g., sleep, metabolism, memory), as well as in pathology, when the dysregulation of immune molecules may occur. This recognition is especially critical in the area of brain development. Microglia and astrocytes, the primary immunocompetent cells of the CNS, are involved in every major aspect of brain development and function, including synaptogenesis, apoptosis, and angiogenesis. Cytokines such as tumor necrosis factor (TNF)α, interleukin [IL]-1β, and IL-6 are produced by glia within the CNS, and are implicated in synaptic formation and scaling, long-term potentiation, and neurogenesis. Importantly, cytokines are involved in both injury and repair, and the conditions underlying these distinct outcomes are under intense investigation and debate. Evidence from both animal and human studies implicates the immune system in a number of disorders with known or suspected developmental origins, including schizophrenia, anxiety/depression, and cognitive dysfunction. We review the evidence that infection during the perinatal period of life acts as a vulnerability factor for later-life alterations in cytokine production, and marked changes in cognitive and affective behaviors throughout the remainder of the lifespan. We also discuss the hypothesis that long-term changes in brain glial cell function underlie this vulnerability.

Maternal immunoglobulin E and childhood leukemia

Childhood leukemia, particularly acute lymphoblastic leukemia (ALL), has long been hypothesized to be affected by abnormal immune responses to microbial challenges stemming from a lack of immune modulation in early childhood. Studies of allergies suggest that a child's immune development may be modulated by maternal immune status. We conducted a study to explore the relationship between maternal immunoglobulin E (IgE) and childhood leukemia and to investigate whether maternal immune status can influence childhood leukemia risk. Serum total and specific IgE (respiratory and food) were measured in biological mothers of 352 children (193 healthy controls and 159 leukemia cases, including 139 ALL cases) ages <8 years who were enrolled in the Northern California Childhood Leukemia Study. Odds ratios associated with maternal IgE were calculated using unconditional logistic regression adjusted for child's age, sex, race/ethnicity, and annual household income. A positive association between childhood leukemia or ALL and elevated levels of maternal serum total IgE was observed, especially among Hispanics. In addition, a positive association was observed between childhood leukemia or ALL and maternal respiratory or food IgE status. These results suggest that maternal immune function may play a crucial role in the etiology of childhood leukemia, although additional studies need to be conducted to confirm the results of this study and provide a perspective on mechanisms.