Severe umbilical cord inflammation-a predictor of periventricular leukomalacia in very low birth weight infants

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.

Risk Factors for Periventricular Leukomalacia in Preterm Infants: A Systematic Review, Meta-analysis, and GRADE-Based Assessment of Certainty of Evidence

BACKGROUND

We analyzed the certainty of evidence (CoE) for risk factors of periventricular leukomalacia (PVL) in preterm neonates, a common morbidity of prematurity.

METHODS

Medline, CENTRAL, Embase, and CINAHL were searched. Cohort and case-control studies and randomised randomized controlled trials were included. Data extraction was performed in duplicate. A random random-effects meta-analysis was utilizedused. CoE was evaluated as per Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidelines.

RESULTS

One hundred eighty-six studies evaluating 95 risk factors for PVL were included. Of the 2,509,507 neonates assessed, 16,569 were diagnosed with PVL. Intraventricular hemorrhage [adjusted odds ratio: 3.22 (2.52-4.12)] had moderate CoE for its association with PVL. Other factors such as hypocarbia, chorioamnionitis, PPROM >48 hour, multifetal pregnancy reduction, antenatal indomethacin, lack of antenatal steroids, perinatal asphyxia, ventilation, shock/hypotension, patent ductus arteriosus requiring surgical ligation, late-onset circulatory collapse, sepsis, necrotizing enterocolitis, and neonatal surgery showed significant association with PVL after adjustment for confounders (CoE: very low to low). Amongst the risk factors associated with mother placental fetal (MPF) triad, there was paucity of literature related to genetic predisposition and defective placentation. Sensitivity analysis revealed that the strength of association between invasive ventilation and PVL decreased over time (P < 0.01), suggesting progress in ventilation strategies. Limited studies had evaluated diffuse PVL.

CONCLUSION

Despite decades of research, our findings indicate that the CoE is low to very low for most of the commonly attributed risk factors of PVL. Future studies should evaluate genetic predisposition and defective placentation in the MPF triad contributing to PVL. Studies evaluating exclusively diffuse PVL are warranted.

Acute chorioamnionitis and intra-amniotic inflammation are more severe according to outside-in neutrophil migration within the same chorio-decidua

OBJECTIVE

No information exists about whether acute histologic chorioamnionitis (acute-HCA) is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. The objective of current study is to examine this issue.

MATERIALS AND METHODS

We included 106 singleton preterm-births (gestational age at delivery: 20-34 weeks) due to either preterm-labor or preterm-PROM in the context of acute chorio-deciduitis. Study-population was divided into 3 groups according to outside-in neutrophil migration within chorio-decidua as follows: 1) group-1: 'inflammation restricted to the decidua' (n = 22); 2) group-2: 'inflammation restricted to the MT of chorion and the decidua' (n = 31); 3) group-3: 'inflammation in the CT of chorion' (n = 53). We examined the frequency of inflammation in each placental compartment beyond chorio-decidua (i.e., amnion, umbilical cord, and chorionic-plate), and total grade (1-8) of acute-HCA. Moreover, the frequency of intra-amniotic infection (defined as positive amniotic-fluid culture for aerobic and anaerobic bacteria and genital mycoplasmas) and intra-amniotic inflammation (defined as amniotic fluid WBC ≥ 19 cells/mm³), and an intra-amniotic inflammatory response gauged by amnioticfluid WBC count (cells/mm³) were examined in 50 amniotic fluid samples within 7 days of birth.

RESULTS

Amnionitis, funisitis and chorionic plate inflammation were more frequent (each for P < 0.01) and median total grade of acute-HCA was increased (P < 0.001) according to outside-in neutrophil migration within chorio-decidua (group-1vs.group-2vs.group-3). Moreover, intra-amniotic infection and inflammation were more frequent (each-for P < 0.05) and median amniotic-fluid WBC count was increased (P < 0.01) according-to outside-in neutrophil-migration within chorio-decidua (group-1 vs. group-2 vs. group-3).

CONCLUSION

Acute-HCA is more advanced and severe, and intra-amniotic inflammation is more frequent and intense according to outside in neutrophil migration within the same chorio-decidua. This finding suggests that what is now acute chorio-deciduitis should be subdivided.

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.

Fetal inflammatory response is positively correlated with the progress of inflammation in chorionic plate

INTRODUCTION

No information exists about the relationship among the progress of inflammation in chorionic-plate, fetal inflammatory response (FIR), funisitis, amnionitis and early-onset neonatal sepsis (EONS) in patients with either preterm labor or preterm premature rupture of membranes (preterm-PROM). The objective of current study is to examine this issue.

METHODS

Study population included 247 singleton preterm gestations (21.6 weeks ≤ gestational age at delivery≤36 weeks) who had either preterm-labor or preterm-PROM with acute placental inflammation. We examined the intensity of FIR, and the frequency of fetal inflammatory response syndrome (FIRS), funisitis, amnionitis and proven or suspected EONS according to the progress of inflammation in chorionic-plate. The intensity of FIR was measured with umbilical cord plasma (UCP)-CRP concentration (ng/ml) at birth, and FIRS was defined as an elevated UCP-CRP concentration (≥200 ng/ml). The progress of inflammation in chorionic-plate was divided with a slight modification from previously reported-criteria as follows: stage-0, inflammation-free chorionic-plate; stage-1, inflammation restricted to subchorionic fibrin (SCF); stage-2, inflammation in the connective tissue (CT) of chorionic-plate without chorionic vasculitis; stage-3, chorionic vasculitis.

RESULTS

1) Stage-0, stage-1, stage-2 and stage-3 of inflammation in chorionic-plate were present in 36.8% (91/247), 29.6% (73/247), 25.5% (63/247), and 8.1% (20/247) of cases; 2) UCP-CRP concentration at birth was significantly and positively correlated with the progress of inflammation in chorionic-plate (Spearman's rank correlation test, P < .000001, γ = 0.391 and Kruskal-Wallis test, P < .001); 3) Moreover, FIRS, funisitis, amnionitis, and EONS were significantly more frequent as a function of the progress of inflammation in chorionic-plate.

DISCUSSION

The intensity of FIR and the frequency of FIRS were positively correlated with the progress of inflammation in chorionic-plate in patients with either PTL or preterm-PROM. This suggests chorionic-plate may be an independent compartment for the analysis of inflammation.

The relationship among the progression of inflammation in umbilical cord, fetal inflammatory response, early-onset neonatal sepsis, and chorioamnionitis

OBJECTIVES

No information exists about whether fetal inflammatory-response(FIR), early-onset neonatal sepsis(EONS) and chorioamnionitis(an advanced-stage of maternal inflammatory-response in extraplacental membranes) continuously increase according to the progression of inflammation in umbilical-cord(UC). The objective of current-study is to examine this-issue.

METHODS

Study-population included 239singleton pregnant-women(gestational-age[GA] at delivery: 21.6~36weeks) who had inflammation in extraplacental membranes or chorionic plate (CP) and either preterm-labor or preterm-PROM. We examined FIR, and the frequency of fetal inflammatory-responses syndrome(FIRS), proven-EONS, suspected-EONS and chorioamnionitis according to the progression of inflammation in UC. The progression of inflammation in UC was divided with a slight-modification from previously reported-criteria as follows: stage0, inflammation-free UC; stage-1: umbilical phlebitis only; stage-2: involvement of at least one UA and either the other UA or UV without extension into WJ; stage-3: the extension of inflammation into WJ. FIR was gauged by umbilical-cord-plasma(UCP) CRP concentration(ng/ml) at birth, and FIRS was defined as an elevated UCP CRP concentration at birth(≥200ng/ml).

RESULTS

Stage-0, stage-1, stage-2 and stage-3 of inflammation in UC were present in 48.1%, 15.5%, 6.7%, and 29.7% of cases. FIR continuously increased according to the progression of inflammation in UC(Kruskal-Wallis test,P<0.001; Spearman-rank-correlation test,P<0.000001,r = 0.546). Moreover, there was a significant and stepwise increase in the frequency of FIRS, proven-EONS, suspected-EONS and chorioamnionitis according to the progression of inflammation in UC(each for P<0.000005 in both chi-square test and linear-by-linear-association). Multiple logistic-regression analysis demonstrated that the more advanced-stage in the progression of inflammation in UC(i.e., stage-1 vs. stage-2 vs. stage-3), the better predictor of suspected-EONS (Odds-ratio[OR]3.358, 95%confidence-interval[CI]:1.020-11.057 vs. OR5.147, 95%CI:1.189-22.275 vs. OR11.040, 95%CI:4.118-29.592) and chorioamnionitis(OR6.593, 95%CI:2.717-15.999 vs. OR16.508, 95%CI:3.916-69.596 vs. OR20.167, 95%CI:8.629-47.137).

CONCLUSION

FIR, EONS and chorioamnionitis continuously increase according to the progression of inflammation in UC among preterm-gestations with inflammation in extraplacental membranes or CP. This finding may suggest that funisitis(inflammation in UC) is both qualitatively and quantitatively histologic-counterpart of FIRS, and a surrogate-marker for chorioamnionitis.

Association Between Funisitis and Childhood Intellectual Development: A Prospective Cohort Study

Background: Previous studies have suggested that prenatal inflammation could damage the immature brain of preterm infants. In this study, we aimed to investigate whether funisitis could affect childhood neurodevelopment. We hypothesized that childhood neurodevelopment would vary across groups with or without funisitis.

Material sand Methods: Using data from the U.S. Collaborative Perinatal Project (1959–1976), 29,725 subjects with available intelligence quotient (IQ) were studied. Detailed placental examinations were conducted according to a standard protocol with quality control procedures. Multivariate logistic regression models were applied to evaluate the relationship between funisitis and IQ at age 4 or 7 years after adjusting for confounders.

Results: Early preterm birth children with funisitis had a 3.0-fold (95% confidence interval 1.2, 7.3) risk of low full-scale IQ (<70) at age 4 years, which disappeared until age 7 years. Term birth children with funisitis had 1.9-fold (95% confidence interval 1.2, 3.0) risk of low performance IQ at age 7 years, but they did not have increased risk of low full-scale IQ. No difference in IQ score was found in late preterm birth children.

Conclusion: Funisitis may injure the developmental brain of infants, leading to the relative low IQ in childhood at age 4, but the negative effect is only existed in performance IQ at age of 7.

Association between perinatal hypoxic-ischemia and periventricular leukomalacia in preterm infants: A systematic review and meta-analysis

Background

Although investigators have implicated hypoxic-ischemia (HI) as a potential cause of periventricular leukomalacia (PVL), the role of clinical risk factors or markers for HI in the development of PVL remains controversial. The aim of this study was to identify perinatal HI-related factors associated with PVL.

Method

The PubMed, EMBASE, and Cochrane Library databases were searched. The last search was performed on January 2017. Summary effect estimates (pooled odds ratios [ORs]) were calculated for each risk factor using fixed or random effects models with tests for heterogeneity and publication bias.

Results

Fifteen studies with a total of 12,851 participants were included in this meta-analysis, and 14 potential risk factors were analyzed. The pooled results showed that mothers with oligohydramnios (OR, 1.55; 95% confidence interval [CI], 1.05 to 2.30), preterm infants with acidemia (OR, 1.87; 95% CI, 1.18 to 2.97), 1-minute Apgar score <7 (OR 2.69; 95% CI, 1.13 to 6.41), 5-minute Apgar score <7 (OR, 1.89; 95% CI, 1.39 to 2.56), apnea (OR, 1.76; 95% CI, 1.07 to 2.90), respiratory distress syndrome (OR, 1.46; 95% CI, 1.04 to 2.03), and seizures (OR, 4.60; 95% CI, 2.84 to 7.46) were associated with increased risk of PVL.

Conclusion

This study identified perinatal HI-related risk factors for the development of PVL in preterm infants. Future large-scale prospective clinical studies are required to validate and extend these findings.

White Matter Injury of Prematurity: Its Mechanisms and Clinical Features

A developing central nervous system is vulnerable to various insults such as infection and ischemia. While increased understanding of the dynamic nature of brain development allows a deeper insight into the pathophysiology of perinatal brain injury, the precise nature of specific fetal and neonatal brain injuries and their short- and long-term clinical consequences need special attention and further elucidation. The current review will describe the pathophysiological aspects and clinical significance of white matter injury of prematurity, a main form of perinatal brain injury in premature newborns, with a particular emphasis on its potential antenatal components.

Ultrasonographic approach to diagnosis of fetal inflammatory response syndrome: a tool for at-risk fetuses?

Preterm parturition is a syndrome that may result from many underlying mechanisms. Infection and inflammation are the prominent ones. Intrauterine infection and inflammation have an effect akin to sepsis, and that is similar to systemic inflammatory response in adults. Indeed, there is evidence to support the association of a fetal inflammatory response syndrome (FIRS) to systemic infection and inflammation. The utilization of invasive procedures for the prenatal diagnosis of FIRS is associated with a risk for complications resulting from the invasive method. The progress in the imaging quality of obstetrical ultrasound and the development of novel methods for functional anatomical assessment of the fetal organs may help to identify, noninvasively, fetuses at risk for FIRS in patients presenting with preterm labor. We review the studies describing advanced sonographic modalities and the imaging findings in the heart, thymus, kidney, adrenal glands, and spleen of these fetuses.

Sterile and microbial-associated intra-amniotic inflammation in preterm prelabor rupture of membranes

OBJECTIVE

The objectives of this study were to: (1) determine the amniotic fluid (AF) microbiology of patients with preterm prelabor rupture of membranes (PROM); and (2) examine the relationship between intra-amniotic inflammation with and without microorganisms (sterile inflammation) and adverse pregnancy outcomes in patients with preterm PROM.

METHODS

AF samples obtained from 59 women with preterm PROM were analyzed using cultivation techniques (for aerobic and anaerobic bacteria as well as genital mycoplasmas) and with broad-range polymerase chain reaction coupled with electrospray ionization mass spectrometry (PCR/ESI-MS). AF concentration of interleukin-6 (IL-6) was determined using ELISA. Results of both tests were correlated with AF IL-6 concentrations and the occurrence of adverse obstetrical/perinatal outcomes.

RESULTS

(1) PCR/ESI-MS, AF culture, and the combination of these two tests each identified microorganisms in 36% (21/59), 24% (14/59) and 41% (24/59) of women with preterm PROM, respectively; (2) the most frequent microorganisms found in the amniotic cavity were Sneathia species and Ureaplasma urealyticum; (3) the frequency of microbial-associated and sterile intra-amniotic inflammation was overall similar [ 29% (17/59)]: however, the prevalence of each differed according to the gestational age when PROM occurred; (4) the earlier the gestational age at preterm PROM, the higher the frequency of both microbial-associated and sterile intra-amniotic inflammation; (5) the intensity of the intra-amniotic inflammatory response against microorganisms is stronger when preterm PROM occurs early in pregnancy; and (6) the frequency of acute placental inflammation (histologic chorioamnionitis and/or funisitis) was significantly higher in patients with microbial-associated intra-amniotic inflammation than in those without intra-amniotic inflammation [93.3% (14/15) versus 38% (6/16); p = 0.001].

CONCLUSIONS

(1) The frequency of microorganisms in preterm PROM is 40% using both cultivation techniques and PCR/ESI-MS; (2) PCR/ESI-MS identified microorganisms in the AF of 50% more women with preterm PROM than AF culture; and (3) sterile intra-amniotic inflammation was present in 29% of these patients, and it was as or more common than microbial-associated intra-amniotic inflammation among those presenting after, but not before, 24 weeks of gestation.

Clinical study of cerebral palsy in 408 children with periventricular leukomalacia

This study aimed to investigate the high risk factors, cerebral palsy (CP) subtypes and comorbidities of periventricular leukomalacia (PVL). Based on treatment conditions at a specialist hospital, a cross-sectional clinical study and retrospective analysis of computed tomography and magnetic resonance imaging examinations was conducted to evaluate the risk factors, subtypes and comorbidities of CP in children with PVL. Among the 408 children with PVL, 8.58% were born with a weight of ≤1,500 g and 44.36% were born with a weight of ≥2,500 g. In addition, 36.76% of these children had a gestational age of ≤32 weeks and 37.75% had a gestational age of ≥37 weeks. The proportion of the children born with various high risk factors was 95.59%, including perinatal infections and hypoxia. Severe PVL was observed in preterm infants (63.41% with a gestational age of <28 weeks and 21.95% with a gestational age of 28-30 weeks) and low-birth weight infants, which were prone to quadriplegia (43.90%). The common comorbidities included visual and auditory disorders, epilepsy, mental retardation and language barriers. Visual and auditory disorders (26.96%) were the most common comorbidities. PVL was identified primarily in premature and low-birth weight infants. The degree of PVL was found to be negatively correlated with gestational age and birth weight. The degree of PVL in the full-term infants correlated with exposure to infections or hypoxia. Quadriplegia is common among the various subtypes of CP. Visual and hearing disorders are the most common comorbidities of CP; these comorbidities occurred most frequently with quadriplegia.

The diagnostic performance of the Mass Restricted (MR) score in the identification of microbial invasion of the amniotic cavity or intra-amniotic inflammation is not superior to amniotic fluid interleukin-6

OBJECTIVE

Intra-amniotic infection/inflammation are major causes of spontaneous preterm labor and delivery. However, diagnosis of intra-amniotic infection is challenging because most are subclinical and amniotic fluid (AF) cultures take several days before results are available. Several tests have been proposed for the rapid diagnosis of microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation. The aim of this study was to examine the diagnostic performance of the AF Mass Restricted (MR) score in comparison with interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8) for the identification of MIAC or inflammation.

METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 100). Intra-amniotic inflammation was defined as >100 white blood cells/mm(3) (WBCs) in AF; MIAC was defined as a positive AF culture. AF IL-6 and MMP-8 were determined using ELISA. The MR score was obtained using the Surface-Enhanced Laser Desorption Ionization Time of Flight (SELDI-TOF) mass spectrometry. Sensitivity and specificity were calculated and logistic regression models were fit to construct receiver-operating characteristic (ROC) curves for the identification of each outcome. The McNemar's test and paired sample non-parametric statistical techniques were used to test for differences in diagnostic performance metrics.

RESULTS

(1) The prevalence of MIAC and intra-amniotic inflammation was 34% (34/100) and 40% (40/100), respectively; (2) there were no significant differences in sensitivity of the three tests under study (MR score, IL-6 or MMP-8) in the identification of either MIAC or intra-amniotic inflammation (using the following cutoffs: MR score >2, IL-6 >11.4 ng/mL, and MMP-8 >23 ng/mL); (3) there was no significant difference in the sensitivity among the three tests for the same outcomes when the false positive rate was fixed at 15%; (4) the specificity for IL-6 was not significantly different from that of the MR score in identifying either MIAC or intra-amniotic inflammation when using previously reported thresholds; and (5) there were no significant differences in the area under the ROC curve when comparing the MR score, IL-6 or MMP-8 in the identification of these outcomes.

CONCLUSIONS

IL-6 and the MR score have equivalent diagnostic performance in the identification of MIAC or intra-amniotic inflammation. Selection from among these three tests (MR score, IL-6 and MMP-8) for diagnostic purposes should be based on factors such as availability, reproducibility, and cost. The MR score requires a protein chip and a SELDI-TOF instrument which are not widely available or considered "state of the art". In contrast, immunoassays for IL-6 can be performed in the majority of clinical laboratories.

Chorioamnionitis in the pathogenesis of brain injury in preterm infants

Chorioamnionitis (or placental infection) is suspected to be a risk factor for brain injury in premature infants. The suggested association between chorioamnionitis and cystic periventricular leukomalacia and cerebral palsy is uncertain because of the variability of study designs and definitions of chorioamnionitis. Improvements in neonatal intensive care may have attenuated the impact of chorioamnionitis on brain health outcomes. Large multicenter studies using rigorous definitions of chorioamnionitis on placental pathologies and quantitative magnetic resonance techniques may offer the optimal way to clarify the complex role of chorioamnionitis in modifying brain health and long-term outcomes.

Prenatal and postnatal inflammation in relation to cortisol levels in preterm infants at 18 months corrected age

OBJECTIVE

To examine whether early inflammation is related to cortisol levels at 18 months corrected age (CA) in children born very preterm.

STUDY DESIGN

Infants born ≤ 32 weeks of gestational age were recruited in the neonatal intensive care unit (NICU), and placental histopathology, magnetic resonance imaging (MRI) and chart review were obtained. At 18 months CA, developmental assessment and collection of three salivary cortisol samples were carried out. Generalized least squares was used to analyze data from 85 infants providing 222 cortisol samples.

RESULT

Infants exposed to chorioamnionitis with funisitis had a significantly different pattern of cortisol across the samples compared with infants with chorioamnionitis alone or no prenatal inflammation (F(4, 139)=7.3996, P<0.0001). Postnatal infections, necrotizing enterocolitis and chronic lung disease were not significantly associated with the cortisol pattern at 18 months CA.

CONCLUSION

In children born very preterm, prenatal inflammatory stress may contribute to altered programming of the hypothalamic-pituitary-adrenal (HPA) axis.

Umbilical cord blood IL-6 as predictor of early-onset neonatal sepsis in women with preterm prelabour rupture of membranes

OBJECTIVE

To evaluate umbilical cord interleukin (IL)-6 and funisitis as independent predictors of early-onset neonatal sepsis (EONS) in preterm prelabor rupture of membranes (PPROM).

DESIGN

Prospective cohort study.

SETTING

Evaluation of umbilical cord IL-6 and funisitis as predictors of early-onset neonatal sepsis in PPROM.

POPULATION

176 women with PPROM between 23+0-36+6 weeks of gestation.

METHODS

Umbilical cord IL-6 was assayed by ELISA. Funisitis was defined according to the Salafia classification. Data was adjusted by gestational age at delivery and prenatal administration of corticosteroids and antibiotics.

MAIN OUTCOME MEASURES

Binary logistic regression was performed to assess the independence of umbilical cord IL-6 and funisitis to predict EONS in women complicated with PPROM.

RESULTS

The rate of EONS was 7%. Funisitis was present in 18% of women. Umbilical cord IL-6 was significantly higher in women complicated with EONS than without [median (range) 389.5 pg/mL (13.9-734.8) vs 5.2 (0.1-801-4), p<0.001]. Umbilical cord IL-6 was the only independent predictor of early-onset neonatal sepsis (odds ratio 13.6, p = 0.004).

CONCLUSION

Umbilical cord IL-6 was the only predictor of early-onset neonatal sepsis in PPROM. Contrary to what is reported, funisitis was not.

Autism spectrum disorder in children born preterm-role of exposure to perinatal inflammation

Autism Spectrum Disorder (ASD) is the collective term for neurodevelopmental disorders characterized by qualitative impairments in social interaction, communication, and a restricted range of activities and interests. Many countries, including Australia, have reported a dramatic increase in the number of diagnoses over the past three decades, with current prevalence of ASD at 1 in every 110 individuals (~1%). The potential role for an immune-mediated mechanism in ASD has been implicated by several studies, and some evidence suggests a potential link between prenatal infection-driven inflammation and subsequent development of ASD. Furthermore, a modest number of contemporary studies have reported a markedly increased prevalence of ASD in children born preterm, who are at highest risk of exposure to perinatal inflammation. However, the mechanisms that underpin the susceptibility to infection-driven inflammation during pregnancy and risk of preterm birth, and how these intersect with the subsequent development of ASD in the offspring, is not understood. This review aims to summarize and discuss the potential mechanisms and evidence for the role of prenatal infection on the central nervous system, and how it may increase the susceptibility for ASD pathogenesis in children born preterm.

DHA supplementation: current implications in pregnancy and childhood

Dietary supplementation with ω-3 long chain fatty acids including docosahexaenoic acid (DHA) has increased in popularity in recent years and adequate DHA supplementation during pregnancy and early childhood is of clinical importance. Some evidence has been built for the neuro-cognitive benefits of supplementation with long chain polyunsaturated fatty acids (LCPUFA) such as DHA during pregnancy; however, recent data indicate that the anti-inflammatory properties may be of at least equal significance. Adequate DHA availability in the fetus/infant optimizes brain and retinal maturation in part by influencing neurotransmitter pathways. The anti-inflammatory properties of LCPUFA are largely mediated through modulation of signaling either directly through binding to receptors or through changes in lipid raft formation and receptor presentation. Our goal is to review the current findings on DHA supplementation, specifically in pregnancy and infant neurodevelopment, as a pharmacologic agent with both preventative and therapeutic value. Given the overall benefits of DHA, maternal and infant supplementation may improve neurological outcomes especially in vulernable populations. However, optimal composition of the supplement and dosing and treatment strategies still need to be determined to lend support for routine supplementation.

Child intellectual development in relation to cytokine levels in umbilical cord blood

Although cytokines play a dual role in the developing neurologic system and in prenatal immune reactions, relations between fetal cytokine levels and child intellectual development remain unknown. The authors investigated associations between umbilical cord serum cytokine concentrations and intellectual outcomes in 369 children within a prospective cohort study, the Eunice Kennedy Shriver National Institute of Child Health and Human Development-University of Alabama Infant Growth Study (1985-1988). Concentrations of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukins 4, 10, and 12p70 were determined. The Wechsler Preschool and Primary Scale of Intelligence-Revised was administered at age 5 years, producing verbal and performance intelligence quotients (VIQ and PIQ); associations with each cytokine were evaluated using linear and logistic regression. Log-unit increases in IFN-γ (adjusted odds ratio (aOR) = 0.67, 95% confidence interval (CI): 0.46, 0.98) and interleukin-12p70 (aOR = 0.43, 95% CI: 0.21, 0.87) were inversely associated with low PIQ (score <70). One log-unit increase in TNF-α was associated with a reduced odds ratio for low VIQ (score <70) among preterm children (aOR = 0.11, 95% CI: 0.01, 0.94) and an elevated odds ratio for low VIQ among small-for-gestational-age children (aOR = 3.96, 95% CI: 0.99, 15.9). IFN-γ, which is involved in neurogenesis and perinatal adaptive immunity, may be related to fetal neurologic development overall, while TNF-α may be a marker of intellectual development in vulnerable subgroups.

Episodes of hypocarbia and early-onset sepsis are risk factors for cystic periventricular leukomalacia in the preterm infant

BACKGROUND

Septic episodes in preterm infants recently have been reported to be associated with periventricular leukomalacia (PVL). The role of hypocarbia as an independent risk factor for PVL in clinical studies raises many questions without conclusive answers.

AIMS

To evaluate risk factors for cystic PVL focussing on the influence of hypocarbia.

STUDY DESIGN

Retrospective single centre case-control study.

SUBJECTS

Preterm infants 24 to 35 weeks of gestational age and matched (1:2 for gender, birth year, gestational age and birth weight) controls.

OUTCOME MEASURES

Multivariate analysis of perinatal factors being associated with cystic PVL diagnosed by serial ultrasound examinations.

RESULTS

Univariate analysis of risk factors revealed lower 5 and 10 min Apgar scores, and higher rates of neonatal seizures, early-onset sepsis, neonatal steroids, respiratory distress syndrome with surfactant replacement therapy, and episodes of hypocarbia significantly being associated with PVL. Multivariate analysis using a logistic regression model revealed early-onset sepsis and hypocarbia being significantly associated with PVL (p=.022 and .024, respectively). Lowest PaCO(2) values did not differ as did not the duration of hypocarbia, but the onset of hypocarbia was significantly later in PVL cases compared to controls (mean 26 vs. 15 h, p=.033). Neurodevelopmental follow-up at a median time of 46 months was poor showing 88% of the cases having an adverse neurological outcome.

CONCLUSION

We found early-onset sepsis and episodes of hypocarbia within the first days of life being independently associated with PVL.

Impact of histological chorioamnionitis, funisitis and clinical chorioamnionitis on neurodevelopmental outcome of preterm infants

BACKGROUND

The role of chorioamnionitis in neurodevelopment of preterm infants is not fully understood.

AIM

To examine the association between different indicators of intrauterine inflammation (clinical chorioamnionitis, histological chorioamnionitis and funisitis) and neurodevelopmental impairment in very preterm infants.

METHODS

Preterm infants with a birth weight of <1500 g or a gestational age of <32 weeks were included. Follow-up evaluation up to 2 years of age consisted of neurological examination, neurodevelopmental assessment and visual and audiologic tests. Outcome data were compared between the chorioamnionitis and the control groups, controlling for gestational age, birth weight and Apgar score at 5 min.

RESULTS

One hundred seventy-seven patients comprised the study population (mean gestational age 29±2 weeks, mean birth weight 1167±344 g). Histological chorioamnionitis was present in 49% of placentas, whereas funisitis was observed in 25%. In 57% cases clinical maternal chorioamnionitis was suspected. Follow-up was available for 130 (82%) patients. Infants with funisitis, compared with controls, had a significantly higher incidence of moderate to severe disability (18% vs 5%, OR 4.07; 95% CI 1.10-15.09).

CONCLUSION

The results of this study suggest that, unlike a broad definition of histological chorioamnionitis including inflammation of maternal or fetal placental tissues, funisitis may entail a higher risk of moderate to severe disability at 2 years of age in preterm infants.

Influence of premature rupture of membrane on the cerebral blood flow in low-birth-weight infant after the delivery

Cerebral white matter injury, usually called periventricular leukomalacia (PVL), is the most common form of injury to preterm infants that is associated with adverse motor and cognitive outcomes. Intrauterine infection may be an important etiological factor in PVL, and premature rupture of the membranes (PROM) can be identified antepartum. In order to investigate the pathophysiology of cerebral white matter injury induced by PROM, the cerebral blood flow (CBF) of the internal carotid artery and the vertebral artery was measured by neck ultrasonography. The CBF was determined in 84 low-birth-weight infants with gestational ages ranging from 24 to 35 weeks, including 71 infants without PROM and 13 infants with PROM. The mean blood flow velocity and diameter of each vessel were measured on postnatal days 0-70. The intravascular flow volume was determined by calculating the mean blood flow velocity and the cross-sectional area. The mean blood pressures were recorded, and the ejection fraction was determined. The total cerebral blood flow (CBF) was significantly lower in infants with PROM than in infants without PROM from day 10 to day 70. The ejection fraction was significantly higher in infants with PROM than in infants without PROM on days 0, 5, 10, 21, and 42. There was no difference in the mean blood pressure between infants with PROM and infants without PROM. The results of the present study suggest that PROM may decrease cerebral blood flow after the birth.

Fetal inflammatory response is often present at early stages of intra-amniotic infection, and its distribution along cord is variable

This study investigates the hypotheses that (1) the fetal inflammatory response to intra-amniotic infection can occur in early stages of maternal inflammatory response and (2) a difference in early cord inflammation exists at different sites in the cord. Placentas accessioned in our department over a 4-year period with a differential in umbilical vessel inflammation between proximal and distal sections were evaluated for cord inflammation using a 0 to 4 graded scale. Cases were also evaluated for acute chorionic vasculitis and extent of maternal inflammatory response. Of 5566 placentas, 1004 (18%) had some degree of cord inflammation; 120 (12%) had a differential in inflammation between the 2 cord sites. Greater cord inflammation was divided almost equally between proximal (59) and distal (61) sections. Twenty-two cases had 1 or both arteries involved in 1 cord section only. The proximal section had the greater degree of inflammation in 21 (95%) of these cases. Early or no maternal inflammatory response was seen in 63 of 120 cases (52%). Acute chorionic vasculitis was identified in 57 of 106 cases (54%) with at least 2 chorionic vessels present. Fetal inflammatory response can be seen in early amniotic infection, occasionally without finding maternal inflammatory response. The absence of differences in cord vein inflammation depending on cord site and the finding that arteritis occurs close to the placental cord insertion site suggest that cord vessel blood flow dynamics play a role in neutrophil margination. At least 2 cord sections representing proximal and distal sites are recommended to exclude fetal inflammatory response.

[Repercussions of premature rupture of fetal membranes on neonatal morbidity and mortality]

The objective of this study was to analyze factors associated with death and survival with sequelae in neonates after premature rupture of fetal membranes (PROM). An observational historical cohort study analyzed charts of patients with PROM at < or = 34 weeks gestation. The variables were compared with neonatal death and survival with sequelae as the outcomes. In both groups, the data were submitted to bivariate analysis, and the variables showing significance were submitted to logistic regression. The final multivariate model for fetal death showed statistical significance for the following: chorioamnionitis; 5-minute Apgar score < or = 5; birth weight < or = 1,000g; and cardiopulmonary resuscitation. Survival with sequela was associated with: cervical colonization; patent ductus arteriosus; 5-minute Apgar score < or = 5; and birth weight < or = 1,000g. Infections, very low birth weight, and peripartum asphyxia were the principal variables associated with the target outcomes among newborns from gestations involving PROM.

Chorioamnionitis and brain damage in the preterm newborn

AIM

To evaluate the association between histological chorioamnionitis and brain damage (intraventricular hemorrhage and cystic periventricular leukomalacia) in the preterm newborn.

METHODS

This was a retrospective study on neonates born at less than 34 weeks gestational age, and their respective mothers, at three tertiary medical centers in the north of Portugal, from January 2001 to December 2002.

RESULTS

The study included 452 newborns (235 male/217 female; birth weight 1440 (515-2620) grams; gestational age 31 (23-33) weeks), 125 from mothers whose placenta showed signs of chorioamnionitis and 327 from mothers without the condition. The association between histological chorioamnionitis and: (1) intraventricular hemorrhage grades I-IV was OR 1.43 (95% CI 0.49-3.94); (2) intraventricular hemorrhage grades III and IV was OR 2.49 (95% CI 1.20-5.11); (3) cystic periventricular leukomalacia was OR 3.02 (95% CI 1.50-6.07). The association, adjusted for birth weight and gestational age, between chorioamnionitis and: (1) intraventricular hemorrhage grades III and IV was OR 0.94 (95% CI 0.39-2.28); (2) cystic periventricular leukomalacia was OR 1.94 (95% CI 1.03-4.61). The association between histological chorioamnionitis with funisitis and/or vasculitis and: (1) intraventricular hemorrhage grades I to IV was OR 1.27 (95% CI 0.52-3.10); (2) cystic periventricular leukomalacia was OR 2.08 (95% CI 0.72-5.98).

CONCLUSION

This study confirms the association between histological chorioamnionitis and cystic periventricular leukomalacia, but was unable to confirm the association between histological chorioamnionitis and intraventricular hemorrhage.

Prenatal lipopolysaccharide increases postnatal intestinal injury in a rat model of necrotizing enterocolitis

BACKGROUND

An increased incidence of necrotizing enterocolitis (NEC) has been noted in infants who are born to mothers with chorioamnionitis.

HYPOTHESIS

Our objective was to test the hypothesis that newborn rat pups born to mothers exposed to prenatal lipopolysaccharide during pregnancy would be more susceptible to intestinal injury in a rat model of NEC and that the increased intestinal injury is mediated by dysregulation of inducible nitric oxide synthase.

METHODS

Time-dated pregnant Sprague-Dawley dams were given an intraperitoneal injection of either 2 mg/kg of lipopolysaccharide or vehicle. Rat pups from each group of dams were delivered at term and placed in a rat NEC model. A subset of pups was given either vehicle or aminoguanidine. Intestines were harvested and graded for degree of intestinal injury.

RESULTS

Maternal prenatal lipopolysaccharide exposure increased the frequency and severity of intestinal injury in the neonatal rat NEC model. Treatment with aminoguanidine significantly decreased plasma nitric oxide levels. Additionally, aminoguanidine significantly decreased intestinal injury.

CONCLUSIONS

Intestinal injury observed may be mediated via nitric oxide synthase dysregulation.

Cystic periventricular leukomalacia in preterm infants: an analysis of obstetric risk factors

OBJECTIVE

To identify obstetric risk factors and to elucidate the effect of prolonged rupture of the membranes on the development of cystic periventricular leukomalacia (PVL) in preterm infants.

METHODS

A retrospective case-control study of 95 preterm infants with the diagnosis of PVL and 245 healthy controls matched for gestational age. A total of 52 antenatal, intrapartum and neonatal characteristics were studied by univariate methods and logistic regression.

RESULTS

Preterm premature rupture of membranes (PPROM) (odds ratio 2.1 [95% CI 1.3-3.4], P=.003), gestational age at PPROM (P=.025), prolonged rupture of membranes (P<.0001), administration of tocolytic agents (1.8 [1.1-3.0], P=.019) and antibiotics (1.9 [1.2-3.1], P=.008) were associated with PVL. The use of tocolytic agents >24 h (P=.008), prolonged latency between the increase in maternal leukocyte count and birth (P=.034), spontaneous onset of labor (1.8 [1.0-2.9], P=.026), vaginal delivery (1.7 [1.1-2.8], P=.029) and male gender (1.5 [1.0-2.0], P=.04) were found more frequently in PVL cases. Preeclampsia (0.4 [0.1-0.9], P=.034), hypertension at booking (P=.009), sonographic IUGR (P=.020), abnormal blood flow of the umbilical artery (P=.032) and cesarean section without labor (0.5 [0.3-0.8], P=.006) were found less frequently. In logistic regression analysis, prolonged rupture of the membranes (P=.748), preeclampsia (P=.973), the use of antibiotics (P=.617) and beta-sympathomimetic tocolytic agents (P=.563) lost statistical significance, whereas birth weight (P=.036) became significant.

CONCLUSION

PPROM and prolonged rupture of the membranes may provoke adverse effects on the neurodevelopmental outcome of the preterm fetus. These findings may have implications on the obstetric management of PPROM beyond 30 weeks of gestation. Cesarean section without labor was less likely associated with the diagnosis of PVL.

Late circulatory dysfunction and decreased cerebral blood flow volume in infants with periventricular leukomalacia

Periventricular leukomalacia is a major neuropathology in preterm infants associated with adverse motor and cognitive outcome. The cerebral blood flow volume of the internal carotid artery and the vertebral artery was measured by ultrasonography at the neck in 36 low-birth-weight infants with gestational age of 25-34 weeks in order to investigate the pathophysiology of cerebral white-matter injury: 30 infants, normal and 6 infants, diagnosed as PVL. The mean blood flow velocity and diameter of each vessel were measured at postnatal days from day 0 to day 70. The intravascular flow volume was determined by calculating the mean blood flow velocity and the cross-sectional area. The mean blood pressures were recorded and PaCO(2) was determined. The total blood flow volume was significantly lower in infants with PVL than in normal infants on days 0, 1, 21, 28, 35, 42, and 63. The mean blood pressure was significantly lower in infants with PVL than in normal infants on days 7, 14, 21, 28, and 42. We suggest that the total cerebral blood supply is decreased in cases of PVL in the few days after birth and from day 21 to day 42. The results of the present study suggest that a dip in the blood flow volume in the few days after birth might result in subsequent PVL.

The fetal inflammatory response syndrome

The fetal inflammatory response syndrome (FIRS) is a condition characterized by systemic inflammation and an elevation of fetal plasma interleukin-6. This syndrome has been observed in fetuses with preterm labor with intact membranes, preterm prelabor rupture of the membranes, and also fetal viral infections such as cytomegalovirus. FIRS is a risk factor for short-term perinatal morbidity and mortality after adjustment for gestational age at delivery and also for the development of long-term sequelae such as bronchopulmonary dysplasia and brain injury. Multiorgan involvement in FIRS has been demonstrated in the hematopoietic system, thymus, adrenal glands, skin, kidneys, heart, lung, and brain. This article reviews the fetal systemic inflammatory response as a mechanism of disease. Potential interventions to control an exaggerated inflammatory response in utero are also described.

Abnormal white matter appearance on term FLAIR predicts neuro-developmental outcome at 6 years old following preterm birth

Preterm infants are at significant risk of neuro-developmental disorders at school-age. MRI is a potentially useful screening tool of such disorders. Using FLAIR imaging in the preterm infants at term, here we demonstrate that abnormal low-intensity signal in the white matter predicts the neuro-developmental outcome at 6 years.

STUDY DESIGN

Clinical factors associated with white matter appearance on MRI obtained at term were investigated in 210 preterm infants.

RESULTS

Low-intensity signal on FLAIR imaging was commonly observed (69%) at <2 months corrected-age. Its incidence correlated with corrected-age at scan, maternal pyrexia and cystic periventricular leukomalacia. Low-intensity signal on FLAIR significantly correlated with performance and full-scale developmental quotients, whereas diffuse high-intensity signal on T2-weighted imaging correlated only with the full-scale developmental quotient at 6 years (n = 75, WISC-R). FLAIR imaging, but not T2-weighted imaging, predicted mild neuro-developmental delay.

CONCLUSIONS

FLAIR appeared to detect subtle white matter injury related with neuro-developmental disorders at school-age, whereas T2-weighted imaging seemed to identify relatively more severe injury. FLAIR is a potentially sensitive screening tool that is readily available and easily interpretable.

A paradoxical temporal response of the PTHrP/PPARgamma signaling pathway to lipopolysaccharide in an in vitro model of the developing rat lung

Chorioamnionitis alters lung development, resulting in a paradoxical decrease in the incidence of respiratory distress syndrome but an increase in the incidence of bronchopulmonary dysplasia (BPD). The mechanism(s) underlying this disparity in the pulmonary outcomes is not known. We hypothesized that specific alterations in alveolar epithelial-mesenchymal interactions might explain this apparent disparity in the pulmonary outcome following chorioamnionitis. We determined the effects of lipopolysaccharide (LPS) on parathyroid hormone-related protein (PTHrP)-driven epithelial-mesenchymal interactions that are essential for normal lung development and homeostasis. Lung explants from embryonic day 19.5 Sprague-Dawley rat fetuses were treated with LPS with or without a PTHrP pathway agonist, prostaglandin J(2) (PGJ(2)). LPS treatment affected the production of proinflammatory cytokines and the expression of the key markers of the epithelial-mesenchymal paracrine interactions in a time-dependent manner. At 6 h, there was a significant increase in the expression of PTHrP and the other key markers of alveolar homeostasis without any significant effect on alpha-smooth muscle actin (alphaSMA). In contrast, at 72 h, there was a significant decrease in the expression of PTHrP and the other key markers of alveolar homeostasis accompanied by a significant increase in alphaSMA expression. The cytokine and molecular changes at 72 h were completely prevented by the concomitant treatment with PGJ(2). We speculate that these data provide a likely mechanism for the acute stimulation of lung differentiation, accompanied paradoxically by BPD following chorioamnionitis, and suggest that by specifically targeting PTHrP signaling, the inflammation-induced molecular injury that is known to result in BPD can be prevented.

Cerebral palsy and fetal inflammatory response syndrome: a review

Cerebral palsy (CP) is the most common cause of severe physical disability in childhood. The precise etiological factor for the development of the majority of cases of CP has not been identified, however, prematurity is considered to be the leading identifiable risk factor. During the last decade, intrauterine infection/inflammation has been identified as the most common cause of preterm delivery and neonatal complications. When microorganisms or their products gain access to the fetus they stimulate the production of cytokines and a systemic response termed FIRS (Fetal Inflammatory Response Syndrome). Subsequently, FIRS was implicated as a cause of fetal or neonatal injury that leads to CP and chronic lung disease. Several authors found an increase in the risk for CP in infants born to mothers with clinical chorioamnionitis, especially in preterm neonates. A relationship between CP and intra-amniotic inflammation was demonstrated, intrauterine infection may lead to activation of the cytokine network which in turn can cause white matter brain damage and preterm delivery, as well as the future development of CP. This white matter insult is identified clinically as periventricular leucomalacia (PVL) which is associated with the subsequent development of impaired neurological outcomes of variable severity including CP.

Neonatal infection and long-term neurodevelopmental outcome in the preterm infant

PURPOSE OF REVIEW

The relationship between infection, the inflammatory response and adverse neurodevelopmental outcome in preterm infants is slowly being elucidated. The developing brain, particularly the periventricular white matter, is vulnerable to cytotoxic and hypoxic/ischemic injury, which places these infants at increased risk for abnormal cognitive and motor functioning. This review summarizes current data evaluating associations between infection and neurodevelopmental outcome in the preterm infant.

RECENT FINDINGS

Preterm infants are at risk for intrauterine and postnatal infections. Recent studies have linked infection/inflammation associated with chorioamnionitis, sepsis and necrotizing enterocolitis with adverse neurodevelopmental outcome and impaired growth in preterm infants. Investigators have also shown associations between infection and brain injury, including severe intraventricular hemorrhage and periventricular leukomalacia. Very-low-birth-weight preterm infants are at substantial risk for neonatal infection, with associated morbidity and mortality. It is postulated that exposure of the preterm brain to inflammatory mediators during infectious episodes contributes to brain injury and poor developmental outcome.

SUMMARY

Enhanced understanding of the interaction of infection, inflammation and brain injury will be critical to developing strategies to improve neurodevelopmental outcome in preterm infants.

Hemodynamics of the cerebral arteries of infants with periventricular leukomalacia

OBJECTIVE

This study investigated the developmental changes in blood flow in each cerebral artery among infants with and without periventricular leukomalacia (PVL), to elucidate the time of onset of PVL.

METHODS

Eight of 67 low birth weight infants were diagnosed through ultrasonography as having PVL with cyst formation. The mean cerebral blood flow velocities (CBFVs) in the anterior cerebral artery, middle cerebral arteries (MCAs), posterior cerebral arteries (PCAs), internal carotid arteries (ICAs), and basilar artery were measured with Doppler ultrasonography at postnatal days 0, 1, 2, 3, 4, 5, 7, 10, 14, 21, 28, 42, 56, and 70. Four of 8 infants with cyst formation and 1 of 59 infants without cyst formation developed cerebral palsy.

RESULTS

The mean CBFVs of infants with PVL were significantly lower in the anterior cerebral artery (days 14-70), the right MCA (days 14-70), the left MCA (days 14-70), the right PCA (days 7-70), the left PCA (days 5-70), the right ICA (days 7-70), the left ICA (days 7-70), and the basilar artery (days 14 and 28-70). The CBFVs in all arteries were also lower among those with PVL than among intact infants on day 0. The CBFVs increased postnatally in the PCAs of infants with intact brains, whereas they remained unchanged after day 14 or 21 among infants with PVL. There was a significant difference in the prevalence of cerebral palsy between the 2 groups.

CONCLUSIONS

We suggest that the total cerebral blood supply is decreased in cases of cystic PVL and that this reduction occurs just after birth, in a defined sequence, in the cerebral arteries. We conclude that the insult resulting in PVL might occur close to the time of birth.

Inflammation in white matter: Clinical and pathophysiological aspects

While the central nervous system (CNS) is generally thought of as an immunopriviledged site, immune-mediated CNS white matter damage can occur in both the perinatal period and in adults, and can result in severe and persistent neurological deficits. Periventricular leukomalacia (PVL) is an inflammatory white matter disease of premature infants that frequently results in cerebral palsy (CP). Clinical and experimental studies show that both hypoxic/ischemic and innate immune mechanisms contribute to the destruction of immature oligodendroglia and of axons in the deep cerebral white matter in PVL. No data are yet available as to whether there is any genetic predisposition to PVL or to its neurological sequelae. Multiple sclerosis (MS) is an inflammatory white matter disease that often begins in young adulthood, causes multifocal destruction of mature oligodendroglia and of axons, and eventually leads to substantial cumulative neurological disability. Certain genetic polymorphisms contribute to susceptibility to MS, and adaptive immune responses to myelin-associated self antigens, or to exogenous antigens that mimic these self antigens, play a central role in the pathophysiology of this disease.

Recruited inflammatory cells mediate endotoxin-induced lung maturation in preterm fetal lambs

RATIONALE

Chorioamnionitis is paradoxically associated with a decreased incidence of respiratory distress syndrome in preterm infants. In preterm lambs, intraamniotic endotoxin and interleukin 1 (IL-1) induce lung inflammation followed by lung maturation.

OBJECTIVE

To test if inflammatory cells are required to mediate induced lung maturation.

METHODS

Lung inflammation was induced by intraamniotic injection of endotoxin or IL-1. Inflammatory cell recruitment to the lung was inhibited by an anti-CD18 blocking antibody given intramuscularly to the fetus. Preterm lambs were delivered at 124-d gestation (term = 150 d) 2 or 7 d after exposure to endotoxin/IL-1 or endotoxin/IL-1 + anti-CD18 antibody.

MEASUREMENTS

Lung inflammation was measured by bronchoalveolar lavage fluid cell count, inflammatory scoring of lung parenchyma, and expression of proinflammatory cytokines and inducible nitric oxide synthase. Lung maturation was quantitated by surfactant protein mRNA expression, saturated phosphatidylcholine pool size, and pressure-volume curves.

MAIN RESULTS

Inhibition of CD18 significantly reduced endotoxin-induced but not IL-1-induced fetal lung inflammatory cell recruitment and activation as well as expression of proinflammatory cytokines. Compared with control lungs, both endotoxin and IL-1 induced lung maturation. Anti-CD18 antibody administration inhibited only endotoxin-induced but not IL-1-induced increases in surfactant protein mRNA and surfactant saturated phosphatidylcholine. Exposure to anti-CD18 antibody moderated endotoxin-induced increases in lung volumes but had no effect on IL-1-induced increases in lung volumes.

CONCLUSIONS

(1) Endotoxin- but not IL-1-induced inflammatory cell recruitment in the preterm fetal lamb lung is CD18 dependent; (2) recruited inflammatory cells mediate some aspects of fetal lung maturation.