Wolfgang Thomas

Chorioamnionitis - the good or the evil for neonatal outcome?

Chorioamnionitis represents a major risk factor for preterm birth and contributes to prematurity-associated morbidity and mortality. Comparison of studies addressing neonatal outcome after exposure to either histological or clinical chorioamnionitis is hampered by the great heterogeneity regarding study cohorts and disease definitions which were applied. Moreover, the impact of exposure to inflammation in utero on neonatal outcome has become less evident with major advances in perinatal and neonatal care. Histologic chorioamnionitis evidently is associated with a reduction of incidence and severity of respiratory distress syndrome. Short-term maturational effects on the lungs of ventilated extremely premature infants are, however, accompanied by a greater susceptibility of the lung, eventually contributing to an increased risk of bronchopulmonary dysplasia. Chorioamnionitis has been shown associated with increased rate of early-onset sepsis but, according to recent data, histological chorioamnionitis might be protective against late-onset sepsis. Inconsistent data exist concerning the true role of chorioamnionitis in the development of brain lesions such as cystic periventricular leukomalacia, diffuse white matter disease, and intraventricular hemorrhage. However, an association with the development of cerebral palsy has been reported.

Chorioamnionitis is essential in the evolution of bronchopulmonary dysplasia - The case in favour

Bronchopulmonary dysplasia (BPD) is a major sequel of extremely premature birth. Multiple ante- and postnatal factors act in concert to injure the immature lung in the pathogenesis of the disease. Among them, chorioamnionitis--according to current evidence--plays a pivotal role. Pulmonary inflammatory processes seen in animal models of chorioamnionitis resemble those seen in premature infants who developed BPD. Chorioamnionitis can doubtlessly induce extremely preterm birth, thus contributing to a gestation-dependent risk of BPD. A gestation-independent association of chorioamnionitis with an increased risk of developing BPD has been demonstrated by a recent systematic review of clinical observational studies. Antenatal inflammation with signs of a systemic fetal response reduces the response to exogenous surfactant in infants with respiratory distress syndrome, leading to a longer need for mechanical ventilation. Moreover, chorioamnionitis increases the risk of early onset sepsis. Both mechanical ventilation and sepsis are, however, major postnatal risk factors for BPD.

Glucocorticoids potentiate IL-6-induced SP-B expression in H441 cells by enhancing the JAK-STAT signaling pathway

The respiratory distress syndrome (RDS) contributes to perinatal morbidity and mortality associated with preterm birth. Surfactant protein B (SP-B) is decreased in RDS. Both maternal antenatal steroid administration and chorioamnionitis reduce the incidence and severity of RDS. An important mediator in chorioamnionitis is IL-6 using the JAK-STAT signaling pathway for signal transduction. We hypothesized that the steroids, betamethasone (BTM) and dexamethasone (DXM), and IL-6 had synergistic effects on SP-B gene expression and STAT3 phosphorylation in H441 cells. DXM and BTM increased SP-B mRNA levels by 16.5 (13.3)-fold and IL-6 alone by 2.3-fold. After 48-h exposure of cells to DXM or BTM, IL-6 caused a significantly greater increase in SP-B mRNA levels (28.1-fold) than IL-6 or glucocorticoids alone. Whereas IL-6 stimulated tyrosine phosphorylation of STAT3 in a time- and dose-dependent way, DXM and BTM had no effect on STAT3 phosphorylation. Both DXM and BTM could potentiate IL-6-induced phosphorylation of STAT3. The synergism of glucocorticoids and IL-6 on SP-B gene expression and the effect of glucocorticoids on IL-6-induced STAT3 phosphorylation could be blocked by a JAK inhibitor. Expression level analysis showed that glucocorticoids increased the expression of the IL-6-binding α-subunit receptor (IL-6R) on mRNA and protein level. Our findings could represent an example of a pulmonary regulation system in which one role of glucocorticoids is to increase the effect of a cytokine by upregulation of its receptor. The described in vitro interaction of IL-6 and glucocorticoids could help explain the clinical observation that prenatal inflammation in preterm babies with antenatal steroid administration can attenuate severity of RDS.

Intrauterine growth retardation in preterm infants ≤32 weeks of gestation is associated with low white blood cell counts.

It is unclear if very immature preterm infants who are born small for gestational age (SGA) have similar leukocyte counts as infants who are born appropriate for gestational age (AGA). Our study included 49 preterm infants with a gestational age ≤32 weeks and without exposure to chorioamnionitis and funisitis. Blood cells were counted in the first 2 hours of life. Eighteen SGA preterm infants were compared with 31 AGA preterm infants. Gestational age, sex, rate of caesarean section, and prenatal administration of corticosteroids did not differ between the groups. Median birth weight was 583 g in the SGA group versus 1100 g in the AGA group. Infants in the SGA group had significantly lower counts of leukocytes, total neutrophils, immature neutrophils, lymphocytes, and monocytes. These findings were not affected by maternal preeclampsia. No significant difference for nucleated red blood cell counts was found. Prenatal growth retardation is an independent factor for lower counts of different leukocytes in very immature preterm infants. It is not clear if these low leukocyte counts are associated with a higher risk of neonatal infections or if lower numbers of inflammatory cells protect the lung and brain of very immature SGA infants by reducing inflammatory events postnatally.

Myocardial response in preterm fetal sheep exposed to systemic endotoxinaemia.

Exposure of the fetus to antenatal inflammation can occur from chorioamnionitis, which may progress to a fetal inflammatory response syndrome (FIRS) and to fetal sepsis. We tested whether the fetal myocardium responded to systemic Gram-negative endotoxinaemia. We hypothesized that the myocardium would respond to inflammation by changes in hypoxia-inducible factor-α (HIF-1α), inducible NO-synthase (iNOS), Toll-like receptors 2 and 4 (TLR2 and TLR4), IL-6, and phosphorylated signal transducer and activator of transcription-3 (pSTAT3). To model systemic endotoxinaemia, fetal sheep were exposed to Gram-negative endotoxin or saline i.v. 3 d before preterm delivery at 113 d of gestation (term = 147 d). All endotoxin-exposed animals developed cardiac dysfunction within these 72 h. Cardiac mRNA and protein levels of HIF-1α and TLR2 and TLR4 mRNA increased, whereas STAT3 phosphorylation decreased significantly. IL-6 and iNOS mRNA remained unchanged. Fetal systemic endotoxinaemia induced myocardial inflammation by activating TLR2 and 4. The following cardiac dysfunction seems not to be mediated via cardiac iNOS.

Airway concentrations of angiopoietin-1 and endostatin in ventilated extremely premature infants are decreased after funisitis and unbalanced with bronchopulmonary dysplasia/death.

A systemic inflammatory response of the fetus, reflected by histologic funisitis, is a risk factor for bronchopulmonary dysplasia (BPD). Impaired pulmonary angiogenesis accompanied by simplification and rarification of alveoli is a histologic hallmark of BPD. Angiopoietin-1 mediates vascular development, maturation, and stabilization. Endostatin mainly acts as an angiostatic factor. We hypothesized that funisitis was associated with changes of endostatin and angiopoietin-1 concentrations in the airways and that an imbalance between the factors might be associated with BPD or death. We measured concentrations of angiopoietin-1 and endostatin by enzyme-linked immunosorbent assay in tracheobronchial aspirate fluid samples of 42 ventilated preterm infants during postnatal days 1 through 15. The secretory component for IgA served as reference protein. A standardized histologic examination was used to distinguish three groups: chorioamnionitis, funisitis, and controls without inflammation. Concentrations of the mediators steadily decreased. Funisitis was associated with lower concentrations of both proteins, which might impair their physiologic activities in pulmonary angiogenesis. An increase of the ratio angiopoietin-1/endostatin until day 7 of life indicated a shift of the mediators potentially favoring angiogenesis. However, infants, who developed BPD or died, had a decreased ratio on days 1, 3, and 15, suggesting an imbalance toward inhibition of pulmonary angiogenesis.

Treatment modalities of infants with upper airway obstruction--review of the literature and presentation of novel orthopedic appliances.

Objective To present a new orthopedic method for treatment of infants with Pierre Robin sequence (PRS) and upper airway obstruction (UAO) as an alternative to other established nonsurgical and surgical techniques such as positioning, nasopharyngeal or endotracheal intubation, tongue-lip adhesion, extension, distraction, or tracheostomy. Design Review of the literature and presentation of novel orthopedic appliances. Setting Department of Orthodontics, Dental Clinic, Medical Faculty of the University of Wuerzburg, Germany, Department and Clinic of Pediatrics, Medical Faculty of the University of Wuerzburg, Germany, 2005 to 2008. Patients Seven patients with significant respiratory and feeding difficulties between 0 and 6 months of age. Both patients with nonsyndromic PRS and patients with syndromic PRS were included. Interventions The type of respiratory tract obstruction was defined by nasopharyngoscopy. Patients with type 1 obstruction received a plate with an epiglottic spur; whereas, patients with obstruction type 2, 3, or 4 received a plate with a pharyngeal tube. Results All patients were successfully treated with orthopedic appliances alone. Under plate therapy they showed good oxygen saturation and could consequently be better nourished orally. Conclusions The presented novel method is a noninvasive technique in treatment of infants with UAO.

Funisitis is associated with increased interleukin-10 gene expression in cord blood mononuclear cells in preterm infants ≤32 weeks of gestation

OBJECTIVES A systemic inflammatory response after intrauterine funisitis is assumed to be an important priming factor for acute and chronic pulmonary morbidity and neurological impairment in premature infants. Fetal lymphocytes and monocytes modulate the primary immune response. Genetic regulation of the cytokine-mediated process is partially known. The objective of our study was to examine the pro-inflammatory and anti-inflammatory responses in umbilical cord blood mononuclear cells (CBMC) of preterm infants on the transcriptional level. STUDY DESIGN Fifteen preterm infants with a gestational age ≤32 weeks were enrolled in this prospective study. Funisitis was diagnosed in five of the 15 by histological examination. Gene expression of pro-inflammatory cytokines (TNF-α, IL-8, IL-1β and IL-17) and anti-inflammatory cytokines (IL-10 and TGF-β1) was examined in CBMC by real time reverse transcription polymerase chain reaction. RESULTS Gene expression of IL-10 was significantly higher in the funisitis group compared to unexposed controls (p<0.008). Expression of TGF-β1, TNF-α, IL-8 and IL-1β did not differ significantly between the funisitis and control group. IL-17 was detectable in only two samples. CONCLUSIONS Funisitis is associated with increased IL-10 gene expression in CBMC of preterm infants with a gestational age ≤32 weeks. This might contribute to modulation of postnatal immunoreactions and immunoregulation in these individuals.

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.

Immune-Mediated Severe Hemolytic Crisis with a Hemoglobin Level of 1.6 g/dl Caused by Anti-Piperacillin Antibodies in a Patient with Cystic Fibrosis

We report a 23-year-old female patient with cystic fibrosis developing severe intravascular hemolysis with a minimal hemoglobin level of 1.6 g/dl after 7 days of treatment with piperacillin, consistent with an immune-mediated hemolytic crisis. Twenty days later, the patient could leave the hospital in good condition without any neurological deficit. To our knowledge, this is the lowest reported hemoglobin value caused by hemolytic anemia with intact survival. As piperacillin is commonly used in patients with cystic fibrosis, it is important to monitor the full-blood counts of patients during treatment with piperacillin and to be aware of the potential for hemolytic anemia to develop. Anti-piperacillin antibodies should be considered whenever these patients develop hemolytic anemia or a positive direct antiglobulin test (DAT). Furthermore, drug-fever under piperacillin application could be a warning sign for the development of hemolytic anemia.