Angelika Berger

Immaturity of Infection Control in Preterm and Term Newborns Is Associated with Impaired Toll-Like Receptor Signaling

The impaired infection control related to the functional immaturity of the neonatal immune system is an important cause of infection in preterm newborns. We previously reported that constitutive Toll-like receptor (TLR) 4 expression and cytokine secretion on lipopolysaccharide (LPS) stimulation increases with gestational age. Here, we analyzed constitutive monocyte TLR2 expression and evaluated the expression profiles of the proximal downstream adapter molecule myeloid differentiation factor 88 (MyD88). We further investigated activation of protein kinases p38 and extracellular regulated kinsase (ERK) 1/2 in CD14 monocytes after ex vivo stimulation with bacterial TLR ligands (LPS and lipoteichoic acid [LTA]). The functional outcome of the stimulation was determined by cytokine secretion. Monocytes from 31 preterm newborns (<30 weeks of gestation, n=16; 30-37 weeks of gestation, n=15), 10 term newborns, and 12 adults were investigated. In contrast to TLR4 expression, TLR2 levels did not differ between age groups. However, MyD88 levels were significantly lower in preterm newborns. Activation of p38 and ERK1/2 was impaired in all newborn age groups after stimulation with TLR-specific ligands. Accordingly, after LTA stimulation, the levels of interleukin (IL)-1 beta , IL-6, and IL-8 cytokine production were substantially lower (P<.001) in preterm newborns than in adults. The reduced functional response to bacterial cell wall components appears to be part of the functional immaturity of the neonatal immune system and might predispose premature newborns to bacterial infection.

The bacterial load of Ureaplasma parvum in amniotic fluid is correlated with an increased intrauterine inflammatory response

Ureaplasma spp. are the most frequently isolated microorganisms inside the amniotic cavity and have been associated with spontaneous abortion, chorioamnionitis, premature rupture of the membranes (PROM), and preterm labor (PL). We analyzed 118 samples from amniotic fluid of preterm infants before 34 weeks of gestation by quantitative polymerase chain reaction (qPCR). Bacterial load, Ureaplasma biovar discrimination (Ureaplasma urealyticum and Ureaplasma parvum), and the level of inflammation were correlated with short-term clinical outcome. U. parvum was the predominant biovar, and increased bacterial load was significantly linked to histologic chorioamnionitis, PROM + PL, early-onset sepsis, and bronchopulmonary dysplasia. Furthermore, there was a positive correlation between the amount of U. parvum and the magnitude of inflammatory response inside the amniotic cavity observed by elevated interleukin 8 levels. We postulate that the bacterial load of Ureaplasma spp. measured by qPCR should be determined in studies investigating the potential clinical impact of intrauterine Ureaplasma spp. on the outcome of preterm infants.

The Poly(I:C)-induced maternal immune activation model in preclinical neuropsychiatric drug discovery

Increasing epidemiological and experimental evidence implicates gestational infections as one important factor involved in the pathogenesis of several neuropsychiatric disorders. Corresponding preclinical model systems based upon maternal immune activation (MIA) by treatment of the pregnant female have been developed. These MIA animal model systems have been successfully used in basic and translational research approaches, contributing to the investigation of the underlying pathophysiological mechanisms at the molecular, cellular and behavioral levels. The present article focuses on the application of a specific MIA rodent paradigm, based upon treatment of the gestating dam with the viral mimic polyinosinic-polycytidilic acid (Poly(I:C)), a synthetic analog of double-stranded RNA (dsRNA) which activates the Toll-like receptor 3 (TLR3) pathway. Important advantages and constraints of this animal model will be discussed, specifically in light of gestational infection as one vulnerability factor contributing to the complex etiology of mood and psychotic disorders, which are likely the result of intricate multi-level gene×environment interactions. Improving our currently incomplete understanding of the molecular pathomechanistic principles underlying these disorders is a prerequisite for the development of alternative therapeutic approaches which are critically needed in light of the important drawbacks and limitations of currently available pharmacological treatment options regarding efficacy and side effects. The particular relevance of the Poly(I:C) MIA model for the discovery of novel drug targets for symptomatic and preventive therapeutic strategies in mood and psychotic disorders is highlighted in this review article.

A Randomized, Controlled Trial of the Effects of Adding Vitamin B12 and Folate to Erythropoietin for the Treatment of Anemia of Prematurity

BACKGROUND. Premature infants, especially those with birth weights of <1500 g, often suffer from anemia of prematurity and associated problems. Erythropoietin therapy is a safe effective way to prevent and to treat anemia of prematurity. We hypothesized that combined administration of vitamin B12 and folate with erythropoietin and iron would enhance erythropoietin-induced erythropoiesis. METHODS. In a randomized, controlled trial, 64 premature infants (birth weight: 801–1300 g) receiving erythropoietin and iron supplementation were assigned randomly to receive either vitamin B12 (3 μg/kg per day) and folate (100 μg/kg per day) (treatment group) or a lower dose of folate (60 μg/kg per day) (control group). RESULTS. During the 4-week observation period, vitamin B12 and folate enhanced erythropoietin-induced erythropoiesis significantly, as indicated by a 10% increase in red blood cell counts, compared with folate alone. Hemoglobin and hematocrit levels remained stable in the treatment group, whereas they decreased in the control group. Vitamin B12 levels in the treatment group increased over baseline and control values, whereas red blood cell folate levels were comparable between the groups. Subsequent analysis showed slight nonsignificant differences in baseline red blood cell count, hemoglobin level, hematocrit level, and mean corpuscular volume values, which must be addressed as a limitation. CONCLUSIONS. With the limitation of a slight imbalance in baseline data between the study groups, combined therapy with vitamin B12, folate, erythropoietin, and orally and intravenously administered iron seemed more effective in stimulating erythropoiesis among premature infants, compared with erythropoietin, iron, and low-dose folate alone. Additional trials are necessary to confirm these data.

Sedation and analgesia practices in neonatal intensive care units (EUROPAIN): results from a prospective cohort study

BACKGROUND Neonates who are in pain or are stressed during care in the intensive care unit (ICU) are often given sedation or analgesia. We investigated the current use of sedation or analgesia in neonatal ICUs (NICUs) in European countries. METHODS EUROPAIN (EUROpean Pain Audit In Neonates) was a prospective cohort study of the management of sedation and analgesia in patients in NICUs. All neonates admitted to NICUs during 1 month were included in this study. Data on demographics, methods of respiration, use of continuous or intermittent sedation, analgesia, or neuromuscular blockers, pain assessments, and drug withdrawal syndromes were gathered during the first 28 days of admission to NICUs. Multivariable linear regression models and propensity scores were used to assess the association between duration of tracheal ventilation (TV) and exposure to opioids, sedatives-hypnotics, or general anaesthetics in neonates (O-SH-GA). This study is registered with ClinicalTrials.gov, number NCT01694745. FINDINGS From Oct 1, 2012, to June 30, 2013, 6680 neonates were enrolled in 243 NICUs in 18 European countries. Mean gestational age of these neonates was 35.0 weeks (SD 4.6) and birthweight was 2384 g (1007). 2142 (32%) neonates were given TV, 1496 (22%) non-invasive ventilation (NIV), and 3042 (46%) were kept on spontaneous ventilation (SV). 1746 (82%), 266 (18%), and 282 (9%) neonates in the TV, NIV, and SV groups, respectively, were given sedation or analgesia as a continuous infusion, intermittent doses, or both (p<0.0001). In the participating NICUs, the median use of sedation or analgesia was 89.3% (70.0-100) for neonates in the TV group. Opioids were given to 1764 (26%) of 6680 neonates and to 1589 (74%) of 2142 neonates in the TV group. Midazolam was given to 576 (9%) of 6680 neonates and 536 (25%) neonates of 2142 neonates in the TV group. 542 (25%) neonates in the TV group were given neuromuscular blockers, which were administered as continuous infusions to 146 (7%) of these neonates. Pain assessments were recorded in 1250 (58%) of 2138, 672 (45%) of 1493, and 916 (30%) of 3017 neonates in the TV, NIV, and SV groups, respectively (p<0.0001). In the univariate analysis, neonates given O-SH-GA in the TV group needed a longer duration of TV than did those who were not given O-SH-GA (mean 136.2 h [SD 173.1] vs 39.8 h [94.7] h; p<0.0001). Multivariable and propensity score analyses confirmed this association (p<0.0001). INTERPRETATION Wide variations in sedation and analgesia practices occur between NICUs and countries. Widespread use of O-SH-GA in intubated neonates might prolong their need for mechanical ventilation, but further research is needed to investigate the therapeutic and adverse effects of O-SH-GA in neonates, and to develop new and safe approaches for sedation and analgesia. FUNDING European Communitys Seventh Framework Programme.

IL-8 concentrations in maternal serum, amniotic fluid and cord blood in relation to different pathogens within the amniotic cavity.

Abstract Objective: The association between elevated interleukin (IL)-8 concentrations in amniotic fluid and preterm delivery is well described. Little consideration has been given to the impact of different groups of microorganisms within the amniotic cavity on IL-8 concentration. Methods: We collected amniotic fluid, placental tissue and amniotic membranes during preterm cesarean sections for bacterial culture. In addition, we determined IL-8 concentrations in maternal serum, amniotic fluid and cord blood and correlated them with the various intra-amniotic pathogens isolated by bacterial culture. Results: IL-8 concentrations were determined in amniotic fluid in 107 cases, in cord blood in 185 cases and in maternal blood in 158 cases. Women with intra-amniotic Ureaplasma urealyticum infection had significantly higher amniotic fluid concentrations of IL-8 than those without (P<0.001). In cord blood, we found significantly elevated IL-8 concentrations due to intra-amniotic infection with U. urealyticum (P=0.045) and other pathogens (P=0.04). In maternal sera, we found no significant elevation of maternal IL-8 in any of the groups. Conclusion: Intrauterine infection with U. urealyticum seems to play a profound role in the cascade of inflammation and increases IL-8 concentrations in amniotic fluid and cord blood.

In utero exposure to Ureaplasma spp. is associated with increased rate of bronchopulmonary dysplasia and intraventricular hemorrhage in preterm infants.

Abstract Aims: We determined the association between short-term neonatal morbidities, such as bronchopulmonary dysplasia (BPD) and intraventricular hemorrhage (IVH), and Ureaplasma spp. in amniotic fluid, placental and amniotic mem-brane of preterm infants. Methods: This study enrolled 257 patients who were born by cesarean section at <34 weeks’ gestation. Patients were divided into two groups according to detection of Ureaplasma spp. by culture-based and/or polymerase chain reaction (PCR) techniques. Results: Significant differences were observed between both groups for all IVH (P=0.032) and IVH grades III or IV (P=0.013), as wells as for BPD [odds ratio (OR) 5.46, 95% confidence interval (CI) 2.02–14.77], oxygen requirement at 28 days postnatal age (OR 1.93, 95% CI 1.00–3.70), and for death between 28 days and 36 postmenstrual weeks or BPD (OR 4.20, 95% CI 1.77–9.96). Ureaplasma spp. was a significant predictor (P<0.001) of BPD after correcting for birth weight (P=0.003) and positive pressure ventilation (P=0.001). Conclusions: In our study population Ureaplasma spp. was associated with BPD and IVH in preterm infants even after adjustment for multiple risk factors.

Effects of a Combined Therapy of Erythropoietin, Iron, Folate, and Vitamin B12 on the Transfusion Requirements of Extremely Low Birth Weight Infants

OBJECTIVES. Erythropoietin is frequently administered to premature infants to stimulate erythropoiesis. The primary goal of erythropoietin therapy is to reduce transfusions, but the efficacy of erythropoietin has not been convincingly demonstrated in this regard. The aim of this trial was to investigate whether combined administration of vitamin B12, folic acid, iron, and erythropoietin could decrease transfusion requirements in extremely low birth weight infants. PATIENTS AND METHODS. In a randomized, controlled trial, extremely low birth weight infants with a birth weight ≤800g and a gestational age ≤32 weeks were randomly assigned to a group receiving combination treatment or a control arm. RESULTS. The treatment increased levels of folate in red blood cells, vitamin B12, ferritin, transferrin receptor levels in plasma, and reticulocyte counts. The proportion of infants requiring no transfusions was lower in the treatment group (38%) as compared with controls (5%). The treatment group and the need for mechanical ventilation were independent predictors of the number of transfusions in multiple regression analysis. Cox regression analysis indicated that combined therapy resulted in a 79% risk reduction for any transfusion. CONCLUSION. Combined treatment with erythropoietin, intravenous iron, folate, and vitamin B12 during the first weeks reduces the need for transfusion in extremely low birth weight infants.

Probiotics ( Lactobacillus acidophilus and Bifidobacterium bifidum ) prevent NEC in VLBW infants fed breast milk but not formula

Background:Specific probiotics prevent necrotizing enterocolitis (NEC). A mixture of lactobacilli and bifidobacteria (Infloran) was highly effective in Asian very-low-birth-weight (VLBW) infants. We analyzed the effect of Infloran on NEC, NEC severity, and the influence of enteral feedings (breast milk vs. formula) on NEC prevention in a cohort of European VLBW infants.Methods:Infloran was implemented for routine use at our department. VLBW infants receiving probiotics were prospectively followed (2010–2012) and compared with historic controls (2008–2009). Data on NEC, neonatal morbidity, feeding tolerance, and descriptive parameters on NEC cases were analyzed.Results:Infloran had no statistically significant impact on NEC (controls: 24/233 (10.3%); probiotics: 16/230 (7%); P = 0.2). However, NEC was significantly reduced in infants of the probiotics group who were fed any breast milk (20/179 (11.2%) vs. 10/183 (5.5%); P = 0.027), whereas it was ineffective in infants exclusively fed formula (4/54 (7.4%) vs. 6/44 (13.6%); P = 0.345). Occurrence of severe NEC (IIIb), time until full feeds, and gastric residuals were similar.Conclusion:Infloran was of lower efficacy in a European VLBW cohort and showed a reduction of NEC only in infants fed breast milk. Future studies should investigate the influence of feeding formula or breast milk on the effect of probiotics.

Changes in thrombopoiesis and platelet reactivity in extremely low birth weight infants undergoing erythropoietin therapy for treatment of anaemia of prematurity.

Erythropoietin (Epo) is frequently administered to premature infants to stimulate erythropoiesis. There is evidence from studies in animals and healthy adults that Epo also interacts with thrombopoiesis and platelet function. This study investigates the effect of Epo therapy on platelet reactivity, peripheral platelet counts and thiazole orange-positive (TO+) platelets in extremely low birth weight (ELBW) infants. In a randomised-controlled trial, ELBW infants with a birth weight < or =800 g and a gestational age < or =32 weeks were either randomised to a group receiving Epo during the first weeks of life or to a control group. Our results show that thrombin receptor-activating peptide (TRAP-6) -induced expression of P-selectin increased significantly during the first two weeks of Epo treatment. With the exception of week five, the number of TO+ platelets was significantly higher during the first eight weeks in Epo-treated infants compared to controls. The increase of TO+ platelets was not paralleled by an increase in total platelet count. We can conclude that Epo therapy has a short-lasting effect on platelet reactivity toTRAP-6 in ELBW infants during the first two weeks of life. Furthermore, Epo therapy is associated with an increase in the number of TO+ platelets compared to controls.