Systemic Fetal Inflammatory Response Research Articles

Recognition of Chorioamnionitis on the Cardiotocograph (CTG): The role of the “Chorio Duck Score”

Chorioamnionitis refers to the inflammation of the chorion and amnion by the bacteria and their toxins as well as by the inflammatory cytokines. Therefore, it is a fetal disease with the bacteria, their toxins as well as the fetal immunological responses involving inflammatory cytokines (interleukins, interferons, and tumour necrosis factor-alpha) exerting their detrimental effects within the fetal compartment (i.e., amniotic fluid, fetal membranes, the placenta, and fetal tissues and organs). The vast majority of fetal inflammation occurs as a result of an ascending infection (i.e., entry of the bacteria from the maternal genital tract through the cervix). Therefore, maternal signs (tachycardia and pyrexia) may not be observed until the late stages of the disease. Cardiotocograph (CTG) trace was introduced into clinical practice in the 1960s as a tool to timely recognise ongoing fetal hypoxic stress so that immediate action could be taken to avoid hypoxic ischaemic encephalopathy (HIE) and/ or intrapartum hypoxia-related perinatal deaths. Unfortunately, the CTG was introduced into clinical practice without any prior randomised controlled trials, which resulted in panicking and reacting to the observed morphology of fetal heart rate decelerations, which reflect an ongoing fetal compensatory response to reduce the myocardial workload. A sudden and reflex reduction of the heart rate in response to ongoing intermittent hypoxic stress (i.e., repetitive compression of the umbilical cord or interruptions in uteroplacental oxygenation due to uterine contractions) would ensure a reduction in myocardial oxygen demand and maintenance of aerobic metabolism to avoid the onset of anaerobic metabolism and production of lactic acid within the myocardium. Lack of understanding of fetal compensatory responses resulted in the illogical approach of grouping arbitrary features into different categories and then randomly combining them to classify the CTG traces into “Normal, Suspicious, and Pathological”. The same parameters were used in fetuses with chorioamnionitis with an alternative, inflammatory pathway of neurological injury. The international consensus guidelines of physiological interpretation of CTG produced by 44 CTG experts from 14 countries in 2018 ensured a paradigm shift and recommended classification of CTG traces based on the type of fetal hypoxia and fetal response to stress, by applying the knowledge of fetal physiology whilst interpreting CTG traces. During the last 5 years, research has highlighted CTG features in fetal neuro-inflammation, which include an absence of fetal heart rate cycling, the ZigZag Pattern, and sinusoidal patterns. The proposed “Chorio Duck Score” is a scoring system based on recently published scientific evidence on CTG features in subclinical and clinical chorioamnionitis to enable timely diagnosis of fetal systemic inflammatory response syndrome (FIRS). This will help avoid the continuation of super-imposed hypoxic stress (i.e., progressive increasing frequency, duration, and strength of uterine contractions) on the background fetal inflammation, to prevent fetal neurological injury.

Heart Rate Variability Code: Does It Exist and Can We Hack It?

A code is generally defined as a system of signals or symbols for communication. Experimental evidence is synthesized for the presence and utility of such communication in heart rate variability (HRV) with particular attention to fetal HRV: HRV contains signatures of information flow between the organs and of response to physiological or pathophysiological stimuli as signatures of states (or syndromes). HRV exhibits features of time structure, phase space structure, specificity with respect to (organ) target and pathophysiological syndromes, and universality with respect to species independence. Together, these features form a spatiotemporal structure, a phase space, that can be conceived of as a manifold of a yet-to-be-fully understood dynamic complexity. The objective of this article is to synthesize physiological evidence supporting the existence of HRV code: hereby, the process-specific subsets of HRV measures indirectly map the phase space traversal reflecting the specific information contained in the code required for the body to regulate the physiological responses to those processes. The following physiological examples of HRV code are reviewed, which are reflected in specific changes to HRV properties across the signal-analytical domains and across physiological states and conditions: the fetal systemic inflammatory response, organ-specific inflammatory responses (brain and gut), chronic hypoxia and intrinsic (heart) HRV (iHRV), allostatic load (physiological stress due to surgery), and vagotomy (bilateral cervical denervation). Future studies are proposed to test these observations in more depth, and the author refers the interested reader to the referenced publications for a detailed study of the HRV measures involved. While being exemplified mostly in the studies of fetal HRV, the presented framework promises more specific fetal, postnatal, and adult HRV biomarkers of health and disease, which can be obtained non-invasively and continuously.

Association of Funisitis with Short-Term Outcomes of Prematurity: A Frequentist and Bayesian Meta-Analysis.

The fetal systemic inflammatory response associated with intra-amniotic inflammation may play a key role in the pathogenesis of complications of preterm birth. Funisitis is the histologic equivalent of the fetal inflammatory response, whereas chorioamnionitis represents a maternal inflammatory response. We conducted a frequentist and Bayesian model average (BMA) meta-analysis of studies investigating the effects of funisitis on short-term outcomes of prematurity. Thirty-three studies (12,237 infants with gestational age ≤ 34 weeks) were included. Frequentist meta-analysis showed that funisitis was associated with an increased risk of any bronchopulmonary dysplasia (BPD), moderate/severe BPD, retinopathy of prematurity (ROP), intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), any sepsis, early-onset sepsis (EOS), and mortality. However, Bayesian meta-analysis showed that the evidence in favor of the alternative hypothesis (i.e., funisitis is associated with an increased risk of developing the outcome) was strong for any IVH, moderate for severe IVH and EOS, and weak for the other outcomes. When the control group was restricted to infants having chorioamnionitis without funisitis, the only outcome associated with funisitis was any IVH. In conclusion, our data suggest that the presence of funisitis does not add an additional risk to preterm birth when compared to chorioamnionitis in the absence of fetal inflammatory response.

Role of Inflammatory Mediators in Endothelial Dysfunction of Umbilical Cord Vessels in Pregnant Women after Third-Trimester Nonprimary Cytomegaloviral Infection

Background. Endothelial cells are the site of productive replication, hematogenous spread and persistence for a variety of viruses, including cytomegalovirus, which play a critical role in the development of vascular complications associated with cytomegalovirus infection due to developing endothelial dysfunction.Aim: to reveal the role of inflammatory mediators (tumor necrosis factor alpha, interleukin-1β, interleukin-8) in the formation of umbilical cord vascular endothelial dysfunction in reactivation of latent cytomegalovirus infection in the third trimester of pregnancy.Material and methods. The standard method of solid-phase (“sandwich” variant) enzyme immunoassay was carried out to study pro-inflammatory cytokines (tumor necrosis factor alpha, interleukin-1β, -8), endothelin-1, nitrite anion in the blood of the umbilical cord of newborns from mothers who come through reactivation of latent cytomegalovirus infection in the third trimester of pregnancy. The work includes examination data of 78 newborns born at 38–40 weeks of gestation. Among them: 45 newborns were born by CMV-seropositive women with reactivation of latent cytomegalovirus infection in the third trimester of pregnancy (main group) and 33 – by CMV-seronegative women (control group). Umbilical vein blood serum was chosen as the material for the study.Results. In the blood of the umbilical vein of newborns from mothers with reactivation of latent cytomegalovirus infection in the third trimester of pregnancy, a high level of pro-inflammatory cytokines was detected: tumor necrosis factor alpha, interleukin-1β, interleukin-8 (p < 0.001) with a simultaneous increase in the content of endothelin-1 and nitrite anion (p < 0.001), compared with similar indicators for healthy newborns.Conclusion. Reactivation of latent cytomegalovirus infection in the third trimester of pregnancy is associated with the formation of a systemic fetal inflammatory response determined by a high concentration of inflammatory mediators (tumor necrosis factor alpha, interleukin-1β, interleukin-8) and an increase in vasoactive compounds (endothelin-1 and nitrite-anion) leading to the formation of dysfunction of the vascular endothelium of the umbilical cord.

The fetal inflammatory response syndrome: the origins of a concept, pathophysiology, diagnosis, and obstetrical implications

The fetus can deploy a local or systemic inflammatory response when exposed to microorganisms or, alternatively, to non-infection-related stimuli (e.g., danger signals or alarmins). The term “Fetal Inflammatory Response Syndrome” (FIRS) was coined to describe a condition characterized by evidence of a systemic inflammatory response, frequently a result of the activation of the innate limb of the immune response. FIRS can be diagnosed by an increased concentration of umbilical cord plasma or serum acute phase reactants such as C-reactive protein or cytokines (e.g., interleukin-6). Pathologic evidence of a systemic fetal inflammatory response indicates the presence of funisitis or chorionic vasculitis. FIRS was first described in patients at risk for intraamniotic infection who presented preterm labor with intact membranes or preterm prelabor rupture of the membranes. However, FIRS can also be observed in patients with sterile intra-amniotic inflammation, alloimmunization (e.g., Rh disease), and active autoimmune disorders. Neonates born with FIRS have a higher rate of complications, such as early-onset neonatal sepsis, intraventricular hemorrhage, periventricular leukomalacia, and death, than those born without FIRS. Survivors are at risk for long-term sequelae that may include bronchopulmonary dysplasia, neurodevelopmental disorders, such as cerebral palsy, retinopathy of prematurity, and sensorineuronal hearing loss. Experimental FIRS can be induced by intra-amniotic administration of bacteria, microbial products (such as endotoxin), or inflammatory cytokines (such as interleukin-1), and animal models have provided important insights about the mechanisms responsible for multiple organ involvement and dysfunction. A systemic fetal inflammatory response is thought to be adaptive, but, on occasion, may become dysregulated whereby a fetal cytokine storm ensues and can lead to multiple organ dysfunction and even fetal death if delivery does not occur (“rescued by birth”). Thus, the onset of preterm labor in this context can be considered to have survival value. The evidence so far suggests that FIRS may compound the effects of immaturity and neonatal inflammation, thus increasing the risk of neonatal complications and long-term morbidity. Modulation of a dysregulated fetal inflammatory response by the administration of antimicrobial agents, anti-inflammatory agents, or cell-based therapy holds promise to reduce infant morbidity and mortality.

Chorioamnionitis exposure remodels the unique histone modification landscape of neonatal monocytes and alters the expression of immune pathway genes.

Chorioamnionitis is an intrauterine infection involving inflammation of the chorion, amnion, and placenta. It leads to a fetal systemic inflammatory response that can alter the transcription of neonatal immune genes. We have previously shown that neonatal monocytes gain the activating histone tail modification H3K4me3 at promoter sites of immunologically important genes as development progresses from preterm neonate to adult. In this study, we applied ChIP-seq and RNA-seq to evaluate the impact of chorioamnionitis on the neonatal monocyte H3K4me3 histone modification landscape over the course of fetal and neonatal immune system development. Chorioamnionitis exposure in neonatal monocytes resulted in a net increase in total monocyte H3K4me3, primarily in introns and intergenic regions. Immune gene expression was decreased in chorioamnionitis-exposed monocytes, with the majority of enriched transcripts falling into pathways that are not linked to the immune system. Over half of all neonatal monocyte H3K4me3 peaks, independent of their location, were associated with active gene transcription. Overall, chorioamnionitis exposure resulted in the global remodeling of the neonatal monocyte H3K4me3 landscape and changes in the expression of known immune genes. These changes resulted in a less robust inflammatory response upon exposure to a secondary challenge, which may explain why chorioamnionitis-exposed neonates have an increased risk of sepsis. DATABASE: ChIP-seq data for U30/O30/Term: GEO GSE81957 ChIP-seq data for U30C/O30C/TermC: GEO GSE111873 RNA-seq data for U/L/CU/CL: GEO GSE111927.

Inflammatory and Immune Proteins in Umbilical Cord Blood: Association with Hearing Screening Test Failure in Preterm Neonates.

Objective We aimed to determine whether elevated levels of various inflammatory and immune proteins in umbilical cord blood are associated with an increased risk of newborn hearing screening (NHS) test failure in preterm neonates. Methods This retrospective cohort study included 127 premature singleton infants who were born at ≤33.6 weeks. Umbilical cord plasma at birth was assayed for interleukin (IL)-6, complement C3a and C5a, matrix metalloproteinase (MMP)-9, macrophage colony-stimulating factor (M-CSF), and endostatin levels using ELISA kits. Neonatal blood C-reactive protein (CRP) levels were measured within 2 hours of birth. The primary outcome measure was a uni- or bilateral refer result on an NHS test. Univariate and multivariate analyses were applied. Results Fifteen (11.8%) infants failed the NHS test. In the univariate analyses, high IL-6 and low C3a levels in umbilical cord plasma, funisitis, and an elevated CRP level (>5 mg/L) in the immediate postnatal period were significantly associated with NHS test failure. However, the levels of umbilical cord plasma MMP-9, C5a, M-CSF, and endostatin were not significantly different between infants who passed and those who failed the NHS test. Multiple logistic regression analyses indicated that elevated umbilical cord plasma C3a levels were independently associated with a reduced risk of NHS test failure, whereas elevated levels of umbilical cord plasma IL-6 and high CRP levels in the immediate postnatal period were significantly associated with NHS test failure. Conclusions Our data demonstrated that in preterm neonates, a systemic fetal inflammatory response reflected by umbilical cord plasma IL-6 and immediate postnatal CRP levels may contribute to the risk for NHS test failure, whereas the changes in complement activation fragments initiated in utero may have protective effect of hearing screen failure.

Maternal and Placental Factors Associated with Congenital Hearing Loss in Very Preterm Neonates

Sensorineural hearing loss (SNHL) is a multifactorial disease that more frequently affects preterm newborns. Although a number of maternal conditions have been reported to be associated with preterm birth, little information is available concerning maternal risk factors for the development of SNHL. We aimed to identify maternal and placental risk factors associated with a "refer" result on the newborn hearing screening (NHS) test and subsequently confirmed SNHL in very preterm neonates. This retrospective cohort study included 267 singleton neonates who were born alive after≤32weeks. Histopathologic examination of the placenta was performed, and clinical data were retrieved from a computerized perinatal database. Cases with two abnormal findings, "refer" on the NHS test, and presence of SNHL on the confirmation test were retrospectively reviewed based on electronic medical records. Forty-two neonates (15.7%) showed a "refer" result, and, on the confirmation test, permanent SNHL was identified in 1.87% (5/267) of all neonates. Multivariate regression analysis revealed that the presence of funisitis was independently associated with a "refer" on the NHS test, whereas use of antenatal corticosteroids was statistically significantly associated with a reduced incidence of "refer" on the screening test. Neither histologic chorioamnionitis nor prematurity (as defined by low gestational age and birth weight) was associated with a "refer" on the NHS test. By contrast, multivariate analysis with occurrence of SNHL as a dependent variable identified no significant associations with the parameters studied, probably owing to the small total number of neonates with permanent SNHL. Presence of funisitis was significantly and independently associated with increased risk of abnormal NHS results, while administration of antenatal corticosteroids was related to a normal NHS result. These findings support the hypothesis that a systemic fetal inflammatory response, manifested as funisitis, might play a role in the pathogenesis of SNHL in preterm neonates.

Low level of tracheal cellular fibronectin in extremely premature infants with funisitis: Relationship with respiratory distress 1 month after birth

Funisitis reflects the fetal systemic inflammatory response in premature infants. Macrophages and neutrophils have been identified as key elements in the inflammatory process of the lungs, and secrete proteases that cause the destruction of the extracellular matrix (ECM). Fibronectin (FN) is the major constituent of the pulmonary ECM and exists in multiple isoforms arising from alternative RNA splicing. Extra domain A (EDA) is the major alternatively spliced segment, and the expression of EDA containing FN (EDA + FN) in the lungs is associated with distal pulmonary cell proliferation during alveolar formation. To study the relationship between the presence of funisitis and EDA + FN levels in the tracheal aspirate fluid (TAF) of infants of less than 28 weeks' gestation. The subjects included in this study were 26 extremely premature infants of <28 weeks' gestation at <24 hr of age, from whom the TAF was collected. These preterm infants were divided into two groups according to placental histology. The funisitis (+) group (n = 9) was compared with the funisitis (-) group (n = 17). The TAF supernatants were analyzed for IL-1β, IL-6, IL-8, neutrophil elastase, and EDA + FN using enzyme-linked immunosorbent assay (ELISA). There were no significant differences in gestational age or birthweight between these groups. The funisitis (+) group had a significantly higher ventilator setting (inspired O(2) × mean airway pressure) at Day 28 than the funisitis (-) group. In the TAF, the concentrations of IL-1β were significantly higher in the funisitis (+) group than in the funisitis (-) group, as were the concentrations of neutrophil elastase. The concentrations of EDA + FN were significantly lower in the funisitis (+) group than in the funisitis (-) group. Decreased EDA + FN in TAF might be one of the risk factors leading to respiratory distress in extremely premature infants with funisitis.

Characterization of the Fetal Blood Transcriptome and Proteome in Maternal Anti‐Fetal Rejection: Evidence of a Distinct and Novel Type of Human Fetal Systemic Inflammatory Response

The human fetus is able to mount a systemic inflammatory response when exposed to microorganisms. This stereotypic response has been termed the 'fetal inflammatory response syndrome' (FIRS), defined as an elevation of fetal plasma interleukin-6 (IL-6). FIRS is frequently observed in patients whose preterm deliveries are associated with intra-amniotic infection, acute inflammatory lesions of the placenta, and a high rate of neonatal morbidity. Recently, a novel form of fetal systemic inflammation, characterized by an elevation of fetal plasma CXCL10, has been identified in patients with placental lesions consistent with 'maternal anti-fetal rejection'. These lesions include chronic chorioamnionitis, plasma cell deciduitis, and villitis of unknown etiology. In addition, positivity for human leukocyte antigen (HLA) panel-reactive antibodies (PRA) in maternal sera can also be used to increase the index of suspicion for maternal anti-fetal rejection. The purpose of this study was to determine (i) the frequency of pathologic lesions consistent with maternal anti-fetal rejection in term and spontaneous preterm births; (ii) the fetal serum concentration of CXCL10 in patients with and without evidence of maternal anti-fetal rejection; and (iii) the fetal blood transcriptome and proteome in cases with a fetal inflammatory response associated with maternal anti-fetal rejection. Maternal and fetal sera were obtained from normal term (n = 150) and spontaneous preterm births (n = 150). A fetal inflammatory response associated with maternal anti-fetal rejection was diagnosed when the patients met two or more of the following criteria: (i) presence of chronic placental inflammation; (ii) ≥80% of maternal HLA class I PRA positivity; and (iii) fetal serum CXCL10 concentration >75th percentile. Maternal HLA PRA was analyzed by flow cytometry. The concentrations of fetal CXCL10 and IL-6 were determined by ELISA. Transcriptome analysis was undertaken after the extraction of total RNA from white blood cells with a whole-genome DASL assay. Proteomic analysis of fetal serum was conducted by two-dimensional difference gel electrophoresis. Differential gene expression was considered significant when there was a P < 0.01 and a fold-change >1.5. (i) The frequency of placental lesions consistent with maternal anti-fetal rejection was higher in patients with preterm deliveries than in those with term deliveries (56% versus 32%; P < 0.001); (ii) patients with spontaneous preterm births had a higher rate of maternal HLA PRA class I positivity than those who delivered at term (50% versus 32%; P = 0.002); (iii) fetuses born to mothers with positive maternal HLA PRA results had a higher median serum CXCL10 concentration than those with negative HLA PRA results (P < 0.001); (iv) the median serum CXCL10 concentration (but not IL-6) was higher in fetuses with placental lesions associated with maternal anti-fetal rejection than those without such lesions (P < 0.001); (v) a whole-genome DASL assay of fetal blood RNA demonstrated differential expression of 128 genes between fetuses with and without lesions associated with maternal anti-fetal rejection; and (vi) comparison of the fetal serum proteome demonstrated 20 proteins whose abundance differed between fetuses with and without lesions associated with maternal anti-fetal rejection. We describe a systemic inflammatory response in human fetuses born to mothers with evidence of maternal anti-fetal rejection. The transcriptome and proteome of this novel type of fetal inflammatory response were different from that of FIRS type I (which is associated with acute infection/inflammation).

The efficacy of intravenous immunoglobulin on lipopolysaccharide-induced fetal brain inflammation in preterm rats

Interleukin-1 is accepted as one of the major cytokines; it is involved in inflammatory processes and systemic fetal inflammatory response that is triggered by maternal lipopolysaccharide (LPS) injection. Because it is an antiinflammatory agent, we investigated (in the brain damage of rat pups) the role of intravenous immunoglobulin (IVIG) in decreasing interleukin-1 beta (IL-1β) expression and caspase 3 activity that was induced by maternal LPS administration. Dams were divided into 3 groups. Pyrogen-free saline solution (NS) was administered intraperitoneally to group 1; LPS (0.3mg/kg) suspension in NS was administered to groups 2 and 3 at 19 days of gestation. Two hours after the first injection, a second injection of NS was administered intravenously to group 1 (NS+ NS), of IVIG was administered intravenously to group 2 (LPS+ IVIG), and of NS was administered intravenously to group 3 (LPS+ NS). Hysterectomy was performed in one-half of the dams 2 hours after the second injection and in the other one-half of the dams 22 hours after the second injection. Pups were delivered, and the brains were extracted just after delivery. IL-1β expression and caspase 3 activity were determined in brain tissues. For the pups at 4 hours, the IL-1β expression of group 2was significantly lower than groups 1 and 3. For the pups at 24hours, the IL-1β expression of group 2 was significantly lower than group 3 but was similar to group 1. For the pups at 24 hours, caspase 3 activity of groups 1 and 2 were significantly lower than group3. Maternal IVIG administration decreased IL-1β expression and caspase 3 activity in the brain tissue of rat pups, which had been induced by maternal LPS-administration.

A signature of fetal systemic inflammatory response in the pattern of heart rate variability measures matrix: a prospective study in fetal sheep model of lipopolysaccharide (LPS)‐induced sepsis

Fetal cholinergic anti‐inflammatory pathway (CAP) provides negative feedback on systemic inflammation. This is reflected in subtle alterations of fetal heart rate (FHR) variability (fHRV). We hypothesized that distinct patterns of fHRV correlation to pro‐inflammatory cytokines will reflect CAP's spontaneous versus inflammatory response states.We induced variable degrees of inflammatory response with LPS in chronically instrumented near‐term fetal sheep (n=8). CAP activity was quantified by 99 fHRV measures using CIMVA (continuous individualized multivariate variability analysis). We correlated the time‐matched fHRV and TNF‐α, IL‐1β and IL‐6. IL‐6, but not TNF‐α and IL‐1β, peaked at 3 hours. At baseline, a distinct set of seven fHRV measures from invariant, geometric and statistical domains correlated to cytokines. During fetal inflammatory response state, another subset of thirteen fHRV measures from invariant, geometric, statistical and energetic domains correlated to these cytokines.Distinctive subsets of fHRV measures can be identified that correlate with levels of inflammation. This opens a new way to study fetal inflammatory response as a function of neuroimmunological behaviour reflected in patterns of fHRV.Funded by CIHR, FRSQ, MITACS/NeuroDevNet, Molly Towell.

Choriodecidual group B streptococcal inoculation induces fetal lung injury without intra-amniotic infection and preterm labor in Macaca nemestrina.

BackgroundEarly events leading to intrauterine infection and fetal lung injury remain poorly defined, but may hold the key to preventing neonatal and adult chronic lung disease. Our objective was to establish a nonhuman primate model of an early stage of chorioamnionitis in order to determine the time course and mechanisms of fetal lung injury in utero.Methodology/Principal FindingsTen chronically catheterized pregnant monkeys (Macaca nemestrina) at 118–125 days gestation (term = 172 days) received one of two treatments: 1) choriodecidual and intra-amniotic saline (n = 5), or 2) choriodecidual inoculation of Group B Streptococcus (GBS) 1×106 colony forming units (n = 5). Cesarean section was performed regardless of labor 4 days after GBS or 7 days after saline infusion to collect fetal and placental tissues. Only two GBS animals developed early labor with no cervical change in the remaining animals. Despite uterine quiescence in most cases, blinded review found histopathological evidence of fetal lung injury in four GBS animals characterized by intra-alveolar neutrophils and interstitial thickening, which was absent in controls. Significant elevations of cytokines in amniotic fluid (TNF-α, IL-8, IL-1β, IL-6) and fetal plasma (IL-8) were detected in GBS animals and correlated with lung injury (p<0.05). Lung injury was not directly caused by GBS, because GBS was undetectable in amniotic fluid (∼10 samples tested/animal), maternal and fetal blood by culture and polymerase chain reaction. In only two cases was GBS cultured from the inoculation site in low numbers. Chorioamnionitis occurred in two GBS animals with lung injury, but two others with lung injury had normal placental histology.Conclusions/SignificanceA transient choriodecidual infection can induce cytokine production, which is associated with fetal lung injury without overt infection of amniotic fluid, chorioamnionitis or preterm labor. Fetal lung injury may, thus, occur silently without symptoms and before the onset of the fetal systemic inflammatory response syndrome.

Myocardial Response to Chorioamnionitis in Preterm Fetal Sheep

Background and aims: Exposure of the fetus to antenatal inflammation can occur from chorioamnionitis which may progress to a systemic fetal inflammatory response syndrome (FIRS). It is not known whether the fetal myocardium participates in this FIRS. We hypothesized that the myocardium would have indicators of inflammation and injury.Methods: Fetal sheep were exposed to intra-amniotic (IA) endotoxin or saline 2d or 7d before preterm delivery at 124 ± 1 days gestational age of gestation (term 150 days). Protein and mRNA levels in hearts were determined by real-time PCR, Western blotting and immunohistochemistry.Results: After IA exposure 2d before delivery, mRNA decreased compared to controls (100%) for hypoxia-inducible factor (HIF)-1α (18%), inducible NO-synthase (iNOS) (5%), toll-like receptor 2 (TLR2) (12%) and TLR4 (16%). Interleukin (IL)-6 mRNA increased to 146% after 2d and 390% after 7d. Protein levels of phosphorylated signal transducer and activator of transcription (STAT)-3 were decreased to 37% after 7d. HIF-1α protein level in cardiomyocytes decreased to 17 % after 2d. Fetal plasma level of cardiac troponin I decreased at both time points (21%, 47%).Conclusions: Acute (2d) endotoxin-induced chorioamnionitis suppressed mediators of cellular inflammatory response whereas a 7d exposure to endotoxin caused mild cardiac inflammation. There was no indication of severe cardiac injury.

Oxidative Stress in Fetal and Neonatal Brain Development

Free radicals (FRs) are normally generated as by-products of aerobic respiration and various metabolic processes. Oxidative stress (OS) occurs when the production of FRs exceeds the capacity of antioxidant defenses. Nevertheless, a certain amount of OS is required to allow for the normal progression of embryonic and fetal growth. OS has been implicated in the regulation of reproductive processes in both animal and human, such as follicular development, ovulation, fertilization, embryogenesis, placental differentiation and growth. In contrast OS has emerged as a likely promoter of several pregnancy-related disorders, such as spontaneous abortions, embryopathies, preeclampsia, fetal growth restriction, preterm labor and low birth weight. Clinical studies suggest a link between maternal and fetal infection/inflammation and brain damage. The most common view is that intrauterine infection causes a fetal systemic inflammatory response resulting in injury to cerebral white matter. At birth, newborn is exposed to a relatively hyperoxic environment and additional FRs sources such as inflammation, hypoxia, ischemia-reperfusion, glutamate and non protein bound iron (NPBI) release may enhance OS. The susceptibility of the developing brain in extreme low gestational age newborn is due to the intrinsic vascular derangements in the autoregulation of cerebral blood flow and the local metabolic vulnerability, furthermore asphyxia causes an increase in NPBI, that significantly correlates with neurodevelopmental outcome. As matter of fact, a positive correlation exists between the development of IVH and NPBI levels in cord blood suggesting the dangerous potential of NPBI on oligodendrocytes. Brain injury is a leading cause of mortality and disability. The improvement in understanding the pathophysiological mechanisms involved in perinatal brain lesions will allow to identify new neuroprotective strategies.

THE INFLUENCE OF THE FETAL INFLAMMATORY RESPONSE SYNDROME ON POSTNATAL ADAPTATION OF THE NEWBORNS

The fetal inflammatory response syndrome associates with inflammation in placenta which expansion determinates the course of neonatal period. The authors show the role of the inflammation of the fetal part of placenta in the development of systemic fetal inflammatory response syndrome, endothelial activation and neuro-endocrine-immune imbalance. It is possible to conclude that this disorders play important role in manifestation of the clinical symptoms of antenatal infection in the early neonatal period.

Soluble receptor for advanced glycation end products (sRAGE) in tracheobronchial aspirate fluid and cord blood of very low birth weight infants with chorioamnionitis and funisitis

BackgroundA systemic fetal inflammatory response, reflected by histological funisitis is associated with pulmonary morbidity and increased mortality after premature birth. The receptor for advanced glycation end products (RAGE) is a membrane-bound multiligand receptor with a key role in inflammation. Soluble RAGE (sRAGE) is created by alternative mRNA splicing or shedding of the receptor's extracellular domain and can inhibit RAGE-activation. AimsTo assess the association of funisitis with airway and systemic concentrations of sRAGE in very premature infants. MethodsForty-two ventilated infants (gestational age: 27.4±1.8weeks, birth weight: 1017±229g [mean±SD]) were studied. sRAGE concentrations were measured in tracheobronchial aspirate fluid (TAF) on days of life 1, 3, 5, 7 and 10 and in umbilical cord serum of 28 infants by ELISA. The secretory component for IgA (SC) served as reference protein in TAF. Placental tissue, membranes and umbilical cords were examined microscopically to distinguish three groups: chorioamnionitis (n=9), funisitis (n=17) and controls (n=16). ResultsThe funisitis group had lower sRAGE concentrations than both other groups in cord blood serum (median: 0.52ng/ml [25th–75th centile: 0.32–0.91]; control, 1.72 [1.02–2.69]; chorioamnionitis, 1.44 [0.92–1.63], p<0.01) and TAF on day 1 (290ng/ngSC [140–400]; control, 2750 [1470–28920]; chorioamnionitis, 2150 [1220–7140], p<0.01). sRAGE in TAF remained lower in the funisitis than in the chorioamnionitis group on days 3 and 10, p<0.01 respectively. ConclusionsDecreased sRAGE in airways and circulation after funisitis may contribute to an imbalance between pro- and anti-inflammatory factors priming very premature infants for pulmonary injury and increasing the risk of adverse outcome.

Clara Cell Secretory Protein in Tracheobronchial Aspirates and Umbilical Cord Serum of Extremely Premature Infants with Systemic Inflammation

Background: A systemic fetal inflammatory response, reflected by chorioamnionitis with funisitis, is a risk factor for bronchopulmonary dysplasia. Clara cell secretory protein (CC10), a product of pulmonary Clara cells, has anti-inflammatory properties. Local down-regulation of CC10 has been associated with inflammatory lung disease. Increased serum levels of CC10 can indicate injury to alveolar-capillary integrity. Objective: We hypothesized that extremely premature infants with a systemic fetal inflammatory response would have decreased concentrations of CC10 in tracheobronchial aspirates and that CC10 concentrations in umbilical cord serum of these infants would be increased, reflecting alveolar epithelial damage. Methods: We measured CC10 concentrations in tracheobronchial aspirates of 42 ventilated extremely premature infants during their first week of life and in umbilical cord serum of 24 of them by ELISA. Standardized histological examination of the placenta, membranes and umbilical cord was used to identify infants with funisitis. Results: Seventeen infants with funisitis had lower CC10 concentrations in tracheobronchial aspirates on days 1 (p < 0.01) and 3 (p < 0.05) than the remaining 25. Exogenous surfactant treatment was associated with higher CC10 concentrations on day 1 (p < 0.05). Initial leukocyte count correlated inversely with CC10 in tracheobronchial aspirates on days 1–5. Umbilical cord serum concentrations of CC10 did not differ between the infants with funisitis and the controls. Conclusions: Reduced anti-inflammatory CC10 concentrations in airways of extremely premature infants with a fetal inflammatory response might make their lungs susceptible for further postnatal injuries. Umbilical cord serum CC10 is not an indicator for a fetal systemic inflammatory reaction.

Fetal inflammatory response and brain injury in the preterm newborn.

Preterm birth can be caused by intrauterine infection and maternal/fetal inflammatory responses. Maternal inflammation (chorioamnionitis) is often followed by a systemic fetal inflammatory response characterized by elevated levels of proinflammatory cytokines in the fetal circulation. The inflammation signal is likely transmitted across the blood-brain barrier and initiates a neuroinflammatory response. Microglial activation has a central role in this process and triggers excitotoxic, inflammatory, and oxidative damage in the developing brain. Neuroinflammation can persist over a period of time and sensitize the brain to subinjurious insults in early and chronic phases but may offer relative tolerance in the intermediate period through activation of endogenous anti-inflammatory, protective, and repair mechanisms. Neuroinflammatory injury not only destroys what exists but also changes what develops.

Chronic Hypoxemia Absent Bacterial Infection Is One Cause of the Fetal Inflammatory Response Syndrome (FIRS)

The object of the investigation was to determine whether chronic fetal hypoxemia triggers a systemic fetal inflammatory response absent bacterial infection. Chronically hypoxemic (10.5% O(2)) and lipopolysaccharide (LPS; 400 microg/kg of maternal body weight) injected intrauterine (but extra-amniotic) treated pregnant guinea pigs were used with appropriate controls. The presence of bacteria in the amniotic cavity was sought using polymerase chain reaction (PCR). Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) protein levels were measured in fetal sera and amniotic fluid (AF) by a commercially available, sensitive enzyme-linked immunosorbent assay (ELISA; IL-6 and TNF-alpha messenger RNA (mRNA) were also quantified in multiple fetal organs using real-time PCR. Prokaryotic DNA was not amplified from any sample, confirming the animals were not infected. Chronic hypoxemia dramatically increased IL-6 and TNF-alpha proteins in fetal sera and mRNA in lung, heart, and brain. There were no significant changes in either cytokine observed in the AF, fetal membranes, or fetal liver. Intrauterine but extra amniotic LPS also increased IL-6 and TNF-alpha protein in fetal sera and mRNA in lung, heart, and brain, plus increased the levels of both cytokines (protein/mRNA) in AF, fetal membranes, and fetal liver. Thus, an elevation in fetal blood IL-6 is not a specific marker of infection-induced fetal inflammatory response syndrome (FIRS). And in contrast to the fetal blood, an elevation in AF IL-6 seems associated only with LPS-induced FIRS.