Wide use of broad-spectrum antibiotics in very low birth weight infants with spontaneous focal intestinal perforation-is it really justified?

PURPOSE

Very low birth weight (VLBW) infants are at a risk of spontaneous focal intestinal perforation (FIP). Treatment includes supportive care, antibiotics, and drainage with/without surgery. Broad-spectrum antibiotic agents like carbapenems are applied frequently, although their use is not well-supported by the limited evidence of causal pathogens. We hypothesize that the use of carbapenems may not be necessary in VLBW infants with FIP. Our primary objective was to evaluate the antimicrobial use in VLBW infants with FIP in a cohort of the German Neonatal Network (GNN). The secondary objective was to characterize a subset in detail as a benchmark for future targets of stewardship.

METHODS

Data on VLBW infants with FIP was collected prospectively within the GNN, a collaboration of 68 neonatal intensive care units (NICU). With regards to the primary objective, patient characteristics and antimicrobial treatment were extracted from the predefined GNN database. To address our secondary objective, an additional on-site assessment of laboratory and microbiological culture results were performed.

RESULTS

In the GNN cohort, 613/21,646 enrolled infants (2.8%) developed FIP requiring surgery. They were frequently treated with carbapenems (500/613 (81.6%)) and vancomycin (497/613 (81.1%)). In a subset of 124 VLBW infants, 77 (72.6%) had proof of gram-positive bacteria in the abdominal cavity, coagulase-negative staphylococci (CoNS) predominantly. Despite the low prevalence of gram-negative bacteria (n = 6 (4.8%)), the combination of meropenem and vancomycin was prescribed most frequently (n = 96 (78.0%)).

CONCLUSION

The use of carbapenems as broad-spectrum antimicrobials agents might not be justified in most VLBW infants with FIP. Knowledge on the development of the neonatal gut microbiota, local resistance patterns and individual microbiological findings should be taken into consideration when implementing antimicrobial stewardship programs (ASPs).

Extrauterine Placental Perfusion and Oxygenation in Infants With Very Low Birth Weight: A Randomized Clinical Trial

Importance

An extrauterine placental perfusion (EPP) approach for physiological-based cord clamping (PBCC) may support infants with very low birth weight (VLBW) during transition without delaying measures of support.

Objective

To test whether EPP in resuscitation of infants with VLBW results in higher hematocrit levels, better oxygenation, or improved infant outcomes compared with delayed cord clamping (DCC).

Design, Setting, and Participants

This nonblinded, single-center randomized clinical trial was conducted at a tertiary care neonatal intensive care unit. Infants with a gestational age greater than 23 weeks and birth weight less than 1500 g born by cesarean delivery between May 2019 and June 2021 were included. Data were analyzed from October through December 2021.

Intervention

Prior to cesarean delivery, participants were allocated to receive EPP or DCC. In the EPP group, infant and placenta, connected by an intact umbilical cord, were detached from the uterus and transferred to the resuscitation unit. Respiratory support was initiated while holding the placenta over the infant. The umbilical cord was clamped when infants showed regular spontaneous breathing, stable heart rates greater than 100 beats/min, and adequate oxygen saturations. In the DCC group, cords were clamped 30 to 60 seconds after birth before infants were transferred to the resuscitation unit, where respiratory support was started.

Main Outcomes and Measure

The primary outcome was the mean hematocrit level in the first 24 hours after birth. Secondary prespecified outcome parameters comprised oxygenation during transition and short-term neonatal outcome.

Results

Among 60 infants randomized and included, 1 infant was excluded after randomization; there were 29 infants in the EPP group (mean [SD] gestational age, 27 weeks 6 days [15.0 days]; 14 females [48.3%]) and 30 infants in the DCC group (mean [SD] gestational age, 28 weeks 1 day [17.1 days]; 17 females [56.7%]). The mean (SD) birth weight was 982.8 (276.6) g and 970.2 (323.0) g in the EPP and DCC group, respectively. Intention-to-treat analysis revealed no significant difference in mean hematocrit level (mean difference [MD], 2.1 percentage points; [95% CI, -2.2 to 6.4 percentage points]). During transition, infants in the EPP group had significantly higher peripheral oxygen saturation as measured by pulse oximetry (adjusted MD at 5 minutes, 15.3 percentage points [95% CI, 2.0 to 28.6 percentage points]) and regional cerebral oxygen saturation (adjusted MD at 5 minutes, 11.3 percentage points [95% CI, 2.0 to 20.6 percentage points]). Neonatal outcome parameters were similar in the 2 groups.

Conclusions and Relevance

This study found that EPP resulted in similar hematocrit levels as DCC, with improved cerebral and peripheral oxygenation during transition. These findings suggest that EPP may be an alternative procedure for PBCC in infants with VLBW.

Trial Registration

ClinicalTrials.gov Identifier: NCT03916159.

Morbidity of Respiratory Syncytial Virus (RSV) Infections: RSV Compared With Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Children Aged 0-4 Years in Cologne, Germany

The aim of this retrospective analysis was to provide information on how infections with respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in symptoms, clinical course, outcome, and utilization of hospital care. We investigated 748 polymerase chain reaction results from symptomatic children aged 0-4 years in Cologne, Germany. One hundred sixty-nine patients tested positive for RSV (22.6%) and 24 children for SARS-CoV-2 (3.2%). Symptomatic patients with RSV infection were hospitalized significantly longer. RSV-positive patients needed oxygen supplementation significantly more often as well as high-flow therapy. With regard to care efforts, RSV-infected patients put higher pressure on the hospital and utilized more hospital resources.

Peritoneal dialysis in extremely and very low-birth-weight infants

The outcome of extremely low-birth-weight (ELBW) and very low-birth-weight (VLBW) infants has substantially improved in recent years. As acute kidney injury is frequent in these infants due to various risk factors, there is an increasing demand for renal replacement therapy in these patients. Data on that topic, however, are scarce. We review the available literature on that topic and report our experience on temporary dialysis in three extremely immature infants (two ELBW and one VLBW) with acute kidney failure. Peritoneal dialysis (PD) was performed for 19, 23, and 44 days until recovery of native renal function. At recent follow-up of 18 and 24 months, two patients are in good clinical condition with chronic kidney disease stages 1 and 4, respectively. One patient deceased at the age of 12 months due to secondary liver failure. The dialysis regimen applied in our study differed significantly from older infants with extremely short dwell times and accordingly high numbers of daily cycles. The use of rigid acute PD catheters was associated with less catheter-related complications (leakage, dislocation, and obstruction) as compared to ascites drainage catheters. In summary, PD was technically feasible and effective also in extremely immature infants, but frequent adjustments of dialysis regimens and high numbers of daily cycles posed immense efforts on both, parents and medical staff.

Supporting breathing of preterm infants at birth: a narrative review

Most very preterm infants have difficulty aerating their lungs and require respiratory support at birth. Currently in clinical practice, non-invasive ventilation in the form of continuous positive airway pressure (CPAP) and positive pressure ventilation (PPV) is applied via facemask. As most very preterm infants breathe weakly and unnoticed at birth, PPV is often administered. PPV is, however, frequently ineffective due to pressure settings, mask leak and airway obstruction. Meanwhile, high positive inspiratory pressures and spontaneous breathing coinciding with inflations can generate high tidal volumes. Evidence from preclinical studies demonstrates that high tidal volumes can be injurious to the lungs and brains of premature newborns. To reduce the need for PPV in the delivery room, it should be considered to optimise spontaneous breathing with CPAP. CPAP is recommended in guidelines and commonly used in the delivery room after a period of PPV, but little data is available on the ideal CPAP strategy and CPAP delivering devices and interfaces used in the delivery room. This narrative review summarises the currently available evidence for why PPV can be inadequate at birth and what is known about different CPAP strategies, devices and interfaces used the delivery room.

Intranasal breast milk for premature infants with severe intraventricular hemorrhage-an observation

For nasal application of neurotrophins and mesenchymal stem cells, successful delivery to the brain and therapeutic effects are known from experimental data in animals. Human breast milk contains neurotrophins and stem cells, but gavage tube feeding in preterm infants bypasses the naso-oropharynx. This is a first exploration on additional nasal breast milk and neuromorphological outcome after severe neonatal brain injury. We present a retrospective summary of 31 very low birth weight preterm infants with intraventricular hemorrhage °3/4 from one third-level neonatal center. All were breast milk fed. Sixteen infants additionally received nasal drops of fresh breast milk daily with informed parental consent for at least 28 days. Cerebral ultrasound courses were reviewed by a pediatric radiologist blinded to the intervention. The main outcome measure was severity of porencephalic defects before discharge. Clinical covariates were comparable in both groups. With nasal breast milk, a trend to a lower incidence for severe porencephalic defects (21% vs. 58%) was detected. Incidences were lower for progressive ventricular dilatation (71% vs. 91%) and surgery for posthemorrhagic hydrocephalus (50% vs. 67%).Conclusion: The hypothesis is generated that early intranasal application of breast milk could have a beneficial effect on neurodevelopment in preterm infants. Controlled investigation is needed. What is Known: • Successful delivery to the brain and therapeutic effects are known for nasal application of neurotrophins and mesenchymal stem cells from experimental data in animal studies. • Human breast milk contains neurotrophins and stem cells, but gavage tube feeding in preterm infants bypasses the naso-oropharynx. What is New: • This is the first report on additional nasal breast milk application in very low birth weight preterm infants with severe brain injury observing a trend for less severe porencephalic defects. • The hypothesis is generated that nasal breast milk might exert neuroprotective effects in preterm infants.

Comparison of Two Respiratory Support Strategies for Stabilization of Very Preterm Infants at Birth: A Matched-Pairs Analysis

Objective: Respiratory support for stabilizing very preterm infants at birth varies between centers. We retrospectively compared two strategies that involved either increasing continuous positive airway pressures (CPAP), or increasing oxygen supplementation. Methods: Matched-pairs of infants (<28 weeks of gestation) were born either at the Leiden University Medical Center [low-pressure: CPAP 5-8 cmH₂O and/or positive pressure ventilation (PPV) and fraction of inspired oxygen (FiO₂) 0.3-1.0; n = 27], or at the University Hospital of Cologne (high-pressure: CPAP 12-35 cmH₂O, no PPV and FiO₂ 0.3-0.4; n = 27). Respiratory support was initiated non-invasively via facemask at both units. Infants (n = 54) were matched between centers for gestational age and birth weight, to compare physiological and short-term clinical outcomes. Results: In the low-pressure group, 20/27 (74%) infants received 1-2 sustained inflations (20, 25 cm H₂O) and 22/27 (81%) received PPV (1:19-3:01 min) using pressures of 25-27 cm H₂O. Within 3 min of birth [median (IQR)], mean airway pressures [12 (6-15) vs. 19 (16-23) cmH₂O, p < 0.001] and FiO₂ [0.30 (0.28-0.31) vs. 0.22 (0.21-0.30), p < 0.001] were different in low- vs. high-pressure groups, respectively. SpO₂ and heart rates were similar. After 3 min, higher FiO₂ levels [0.62 (0.35-0.98) vs. 0.28 (0.22-0.38), p = 0.005] produced higher SpO₂ levels [77 (50-92) vs. 53 (42-69)%, p < 0.001] in the low-pressure group, but SpO₂/FiO₂ and heart rates were similar. While intubation rates during admission were significantly different (70 vs. 30%, p = 0.013), pneumothorax rates (4 vs. 19%, p = 0.125) and the occurrence of spontaneous intestinal perforations (0 vs. 15%, p = 0.125) were similar between groups. Conclusion: Infants (<28 weeks) can be supported non-invasively at birth with either higher or lower pressures and while higher-pressure support may require less oxygen, it does not eliminate the need for oxygen supplementation. Future studies need to examine the effect of high pressures and pressure titration in the delivery room.

Mask Continuous Positive Airway Pressure Therapy with Simultaneous Extrauterine Placental Transfusion for Resuscitation of Preterm Infants - A Preliminary Study

Background

Delayed cord clamping or cord milking improves cardiovascular stability and outcome of preterm infants. However, both techniques may delay initiation of respiratory support. To allow lung aeration during cord blood transfusion, we implemented an extrauterine placental transfusion (EPT) approach. This study aimed to provide a detailed description of the EPT procedure and to evaluate its impact on the outcome of infants.

Methods

A retrospective analysis was performed comprising 60 preterm infants (22^0/7 to 31^6/7 weeks of gestation). Of these, 40 were transferred to the resuscitation unit with the placenta still connected to the infant. In this EPT group, continuous positive airway pressure support was initiated while, simultaneously, placental blood was transfused by holding the placenta 40-50 cm above the infant's heart. The cords of another 20 infants were clamped before respiratory support was started (standard group). Data on the infants' outcome were compared retrospectively. In a subgroup of 22 infants (n = 14 EPT, n = 8 standard), respiratory function monitor recordings were performed and both heart rates and SpO₂ levels in the first 10 min of life were compared between groups.

Results

Although infants in the EPT group were lighter (EPT: 875 ± 355 g, standard: 1,117 ± 389 g; p = 0.02) and younger (26^6/7 weeks ± 19 days vs. 28^2/7 weeks ± 18 days; p = 0.045), there was no difference in neonatal outcome, including the incidence of intraventricular hemorrhage, bronchopulmonary disease, and red blood cell transfusions (all p > 0.1). Moreover, no differences in SpO₂ levels and heart rates were observed in the infants whose resuscitations were recorded using a respiratory function monitor.

Conclusions

In this retrospective analysis, EPT had no negative effects on the outcome of the infants, which warrants further evaluation in prospective randomized studies.

An Echocardiographic Screening Program Helps to Identify Pulmonary Hypertension in Extremely Low Birthweight Infants with and without Bronchopulmonary Dysplasia: A Single-Center Experience

BACKGROUND

Pulmonary hypertension (PH) affects 1 in 6 infants with a birthweight <1,000 g (extremely low birthweight; ELBW) and is frequently associated with bronchopulmonary dysplasia (BPD). If untreated, the mortality rates of the disease are high.

OBJECTIVES

The aim of this study was to characterize risk factors for PH in ELBW infants and to describe the timing of onset of the disease by setting up a screening program.

METHODS

ELBW infants treated at the Department of Neonatology (level III neonatal intensive care unit at the University of Cologne Medical Centre, Germany) between January 2010 and March 2015 were included. Echocardiography screening for PH was performed either before discharge or if BPD was diagnosed. Additionally, infants had at least 1 echocardiographic scan after discharge. Survival with PH, age at diagnosis of PH, and risk factors associated with PH were assessed.

RESULTS

In total, 34/188 (18%) infants had PH. Of these, 14 (41%) were identified after discharge. Another 11 (32%) were diagnosed with PH without suffering from moderate or severe BPD. The risk factors for diagnosis of PH were moderate (odds ratio, OR 4 [2-8]) or severe BPD (OR 13 [2-71]), prolonged rupture of membranes >7 days (OR 5 [1-19]), and birthweight below the 3rd percentile (OR 3 [1-9]). All infants with PH before discharge and 50% diagnosed after discharge were treated with sildenafil (2.0 mg/kg/day). PH resolved and sildenafil was discontinued in all patients after a median duration of 13 months (IQR 8-20).

CONCLUSIONS

An echocardiographic screening program may help to identify infants with PH. Examinations should include all ELBW infants irrespective of the presence of BPD and be continued after discharge.

Molecular Classification Substitutes for the Prognostic Variables Stage, Age, and MYCN Status in Neuroblastoma Risk Assessment

BACKGROUND: Current risk stratification systems for neuroblastoma patients consider clinical, histopathological, and genetic variables, and additional prognostic markers have been proposed in recent years. We here sought to select highly informative covariates in a multistep strategy based on consecutive Cox regression models, resulting in a risk score that integrates hazard ratios of prognostic variables. METHODS: A cohort of 695 neuroblastoma patients was divided into a discovery set (n = 75) for multigene predictor generation, a training set (n = 411) for risk score development, and a validation set (n = 209). Relevant prognostic variables were identified by stepwise multivariable L1-penalized least absolute shrinkage and selection operator (LASSO) Cox regression, followed by backward selection in multivariable Cox regression, and then integrated into a novel risk score. RESULTS: The variables stage, age, MYCN status, and two multigene predictors, NB-th24 and NB-th44, were selected as independent prognostic markers by LASSO Cox regression analysis. Following backward selection, only the multigene predictors were retained in the final model. Integration of these classifiers in a risk scoring system distinguished three patient subgroups that differed substantially in their outcome. The scoring system discriminated patients with diverging outcome in the validation cohort (5-year event-free survival, 84.9 ± 3.4 vs 63.6 ± 14.5 vs 31.0 ± 5.4; P < .001), and its prognostic value was validated by multivariable analysis. CONCLUSION: We here propose a translational strategy for developing risk assessment systems based on hazard ratios of relevant prognostic variables. Our final neuroblastoma risk score comprised two multigene predictors only, supporting the notion that molecular properties of the tumor cells strongly impact clinical courses of neuroblastoma patients.

A Myc Activity Signature Predicts Poor Clinical Outcomes in Myc-Associated Cancers

Myc transcriptional activity is frequently deregulated in human cancers, but a Myc-driven gene signature with prognostic ability across multiple tumor types remains lacking. Here, we selected 18 Myc-regulated genes from published studies of Myc family targets in epithelial ovarian cancer (EOC) and neuroblastoma. A Myc family activity score derived from the 18 genes was correlated to MYC/MYCN/MYCL1 expression in a panel of 35 cancer cell lines. The prognostic ability of this signature was evaluated in neuroblastoma, medulloblastoma, diffuse large B-cell lymphoma (DLBCL), and EOC microarray gene expression datasets using Kaplan-Meier and multivariate Cox regression analyses and was further validated in 42 primary neuroblastomas using qPCR. Cell lines with high MYC, MYCN, and/or MYCL1 gene expression exhibited elevated expression of the signature genes. Survival analysis showed that the signature was associated with poor outcome independently of well-defined prognostic factors in neuroblastoma, breast cancer, DLBCL, and medulloblastoma. In EOC, the 18-gene Myc activity signature was capable of identifying a group of patients with poor prognosis in a "high-MYCN" molecular subtype but not in the overall cohort. The predictive ability of this signature was reproduced using qPCR analysis of an independent cohort of neuroblastomas, including a subset of tumors without MYCN amplification. These data reveal an 18-gene Myc activity signature that is highly predictive of poor prognosis in diverse Myc-associated malignancies and suggest its potential clinical application in the identification of Myc-driven tumors that might respond to Myc-targeted therapies. Cancer Res; 77(4); 971-81. ©2016 AACR.

Survival Among Infants Born at 22 or 23 Weeks' Gestation Following Active Prenatal and Postnatal Care

IMPORTANCE

Rates of survival for infants born at the border of viability are still low and vary considerably among neonatal intensive care units.

OBJECTIVE

To determine whether higher survival rates and better short-term outcomes for infants born at 22 or 23 weeks' gestation may be achieved by active prenatal and postnatal care.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective study of 106 infants born at 22 or 23 weeks of gestation at a level III neonatal intensive care unit at the University of Cologne Medical Centre in Cologne, Germany, between January 1, 2010, and December 31, 2014. Data analysis was performed in June 2015.

EXPOSURES

Active prenatal and postnatal care.

MAIN OUTCOMES AND MEASURES

Survival until hospital discharge and survival without neonatal or short-term severe complications (defined as high-grade intraventricular hemorrhage, surgery for abdominal complications, bronchopulmonary dysplasia, or retinopathy of prematurity).

RESULTS

Of 106 liveborn infants (45 born at 22 weeks and 61 born at 23 weeks and 6 days), 20 (19%) received palliative care (17 born at 22 weeks and 3 born at 23 weeks), and 86 (81%) received active care (28 born at 22 weeks and 58 born at 23 weeks). Of the 86 infants who received active care (mean [SD] maternal age, 32 [6] years), 58 (67%) survived until hospital discharge (17 born at 22 weeks and 41 born at 23 weeks). Eighty-five infants survived without severe complications, with 1 infant born at 22 weeks excluded because of missing data (6 of 27 [22%] born at 22 weeks, and 16 of 58 [28%] born at 23 weeks). Survival was predicted by the Apgar score after 5 minutes (odds ratio, 0.62 [95% CI, 0.46-0.84]) and birth weight (odds ratio, 0.001 [95% CI, 0.00-0.40]).

CONCLUSIONS AND RELEVANCE

One in 4 infants born at the border of viability and offered active care survived without severe complications. This finding should be considered for individualized parental approaches and decision making. Active follow-up information is required to determine childhood outcomes.

Therapeutic targeting of the MYC signal by inhibition of histone chaperone FACT in neuroblastoma

Amplification of the MYCN oncogene predicts treatment resistance in childhood neuroblastoma. We used a MYC target gene signature that predicts poor neuroblastoma prognosis to identify the histone chaperone FACT (facilitates chromatin transcription) as a crucial mediator of the MYC signal and a therapeutic target in the disease. FACT and MYCN expression created a forward feedback loop in neuroblastoma cells that was essential for maintaining mutual high expression. FACT inhibition by the small-molecule curaxin compound CBL0137 markedly reduced tumor initiation and progression in vivo. CBL0137 exhibited strong synergy with standard chemotherapy by blocking repair of DNA damage caused by genotoxic drugs, thus creating a synthetic lethal environment in MYCN-amplified neuroblastoma cells and suggesting a treatment strategy for MYCN-driven neuroblastoma.

An 18 gene expression-based score classifier predicts the clinical outcome in stage 4 neuroblastoma

Background

The prognosis of children with metastatic stage 4 neuroblastoma (NB) has remained poor in the past decade.

Patients and methods

Using microarray analyses of 342 primary tumors, we here developed and validated an easy to use gene expression-based risk score including 18 genes, which can robustly predict the outcome of stage 4 patients.

Results

This classifier was a significant predictor of overall survival in two independent validation cohorts [cohort 1 (n = 214): P = 6.3 × 10⁻⁵; cohort 2 (n = 27): P = 3.1 × 10⁻²]. The prognostic value of the risk score was validated by multivariate analysis including the established markers age and MYCN status (P = 0.027). In the pooled validation cohorts (n = 241), integration of the risk score with the age and/or MYCN status identified subgroups with significantly differing overall survival (ranging from 35 to 100 %).

Conclusion

Together, the 18-gene risk score classifier can identify patients with stage 4 NB with favorable outcome and may therefore improve risk assessment and treatment stratification of NB patients with disseminated disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0896-7) contains supplementary material, which is available to authorized users.

MYCN amplification confers enhanced folate dependence and methotrexate sensitivity in neuroblastoma

MYCN amplification occurs in 20% of neuroblastomas and is strongly related to poor clinical outcome. We have identified folate-mediated one-carbon metabolism as highly upregulated in neuroblastoma tumors with MYCN amplification and have validated this finding experimentally by showing that MYCN amplified neuroblastoma cell lines have a higher requirement for folate and are significantly more sensitive to the antifolate methotrexate than cell lines without MYCN amplification. We have demonstrated that methotrexate uptake in neuroblastoma cells is mediated principally by the reduced folate carrier (RFC; SLC19A1), that SLC19A1 and MYCN expression are highly correlated in both patient tumors and cell lines, and that SLC19A1 is a direct transcriptional target of N-Myc. Finally, we assessed the relationship between SLC19A1 expression and patient survival in two independent primary tumor cohorts and found that SLC19A1 expression was associated with increased risk of relapse or death, and that SLC19A1 expression retained prognostic significance independent of age, disease stage and MYCN amplification. This study adds upregulation of folate-mediated one-carbon metabolism to the known consequences of MYCN amplification, and suggests that this pathway might be targeted in poor outcome tumors with MYCN amplification and high SLC19A1 expression.

Abstract PR09: MYCN and is a therapeutic target in neuroblastoma

Neuroblastoma is a childhood cancer of the sympathetic nervous system. Approximately 20% of patients present with an aggressive metastatic disease characterized by amplification of the MYCN locus. However, an additional 30% of patients suffer from an equally aggressive disease, yet there are no unified genetic markers available.

To identify potential biomarkers of poor prognosis in neuroblastoma, we conducted unsupervised hierarchical clustering on 649 primary neuroblastoma tumors based on a 51 gene MYC core target signature. This demonstrated strong activation within the MYCN amplified cohort as expected, but surprisingly there was a large subset of MYCN non-amplified patients that exhibited high MYC signaling. High expression of this MYC signature proved to be strongly predictive of poor overall survival, in both the full cohort (Hazard ratio (HR): 47.6, p= 2.7x10-35, n=649) and in MYCN non-amplified patients (HR=32.8, p=1.3x10-13, n=554), suggesting that neuroblastoma can be driven by MYC signaling in the absence of MYCN amplification. To evaluate potential therapeutic targets within this MYC signature, we conducted cox regression analysis on the 51 individual members and identified that SPT16 was a particularly potent predictor of poor outcome in these 649 neuroblastoma patients (HR: 7.2, p=2.7x10-17). SPT16 is a subunit of the FACT histone chaperone complex, which together with its heterodimer partner SSRP1, has previously been shown to function in dynamic regulation of chromatin to drive transcription, DNA replication and DNA repair. Similar to SPT16, high SSRP1 expression was a strong predictor of poor prognosis in 649 neuroblastoma patients (HR: 12.5, p=5.812x10-26) implicating FACT as a mediator of MYC driven neuroblastoma.

Next we investigated the biological relationship between FACT and MYCN in neuroblastoma. siRNA experiments showed that FACT and MYCN participate in a positive feedback transcriptional loop that is essential for maintaining mutual high expression. Immunohistochemistry in sympathetic ganglia of pre-tumor TH-MYCN mouse model of neuroblastoma identified that FACT was highly expressed at tumor initiation and chemical inhibition of FACT by CBL0137 markedly reduced tumor initiation and subsequent tumorigenesis in vivo. Next we tested CBL0137 against established neuroblastoma in TH-MYCN mice. CBL0137 was highly cytotoxic to tumors either as a single agent or by synergistically promoting clinically used chemotherapeutics. This was accompanied by marked MYCN depletion and prolonged tumor regression in a majority of recipient mice. Pulsed-field electrophoresis showed that CBL0137 impaired FACT dependent DNA damage repair in the presence of genotoxic chemotherapy, thus creating a synthetic lethal environment in MYCN-amplified neuroblastoma cells. Together our data define FACT as a mediator of neuroblastoma tumorigenesis and MYCN-related treatment target. Given the current poor survival rates of children with high-risk neuroblastoma, our findings provide support for the clinical development of CBL0137 as a novel treatment approach for this refractory malignancy.

Citation Format: Daniel R. Carter, Jayne Murray, Belamy B. Cheung, Heyam Kalla, Laura Gamble, Joanna Tsang, Selina Sutton, Jessica Koach, Sarah Syed, Andrew Gifford, Natalia Issaeva, Asel Biktasova, Bernard Atmadibrata, Yuting Sun, Nicolas Sokolowski, Dora Ling, Patrick Y. Kim, Hannah Webber, Ashleigh Clark, Michelle Ruhle, Bing Liu, André Oberthuer, Matthias Fischer, Jennifer Byrne, Federica Saletta, Andrei Purmal, David Ziegler, Tao Liu, Katerina V. Gurova, Andrei V. Gudkov, Murray D. Norris, Michelle Haber, Glenn M. Marshall. MYCN and is a therapeutic target in neuroblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Myc: From Biology to Therapy; Jan 7-10, 2015; La Jolla, CA. Philadelphia (PA): AACR; Mol Cancer Res 2015;13(10 Suppl):Abstract nr PR09.

Comparison of RNA-seq and microarray-based models for clinical endpoint prediction

Background

Gene expression profiling is being widely applied in cancer research to identify biomarkers for clinical endpoint prediction. Since RNA-seq provides a powerful tool for transcriptome-based applications beyond the limitations of microarrays, we sought to systematically evaluate the performance of RNA-seq-based and microarray-based classifiers in this MAQC-III/SEQC study for clinical endpoint prediction using neuroblastoma as a model.

Results

We generate gene expression profiles from 498 primary neuroblastomas using both RNA-seq and 44 k microarrays. Characterization of the neuroblastoma transcriptome by RNA-seq reveals that more than 48,000 genes and 200,000 transcripts are being expressed in this malignancy. We also find that RNA-seq provides much more detailed information on specific transcript expression patterns in clinico-genetic neuroblastoma subgroups than microarrays. To systematically compare the power of RNA-seq and microarray-based models in predicting clinical endpoints, we divide the cohort randomly into training and validation sets and develop 360 predictive models on six clinical endpoints of varying predictability. Evaluation of factors potentially affecting model performances reveals that prediction accuracies are most strongly influenced by the nature of the clinical endpoint, whereas technological platforms (RNA-seq vs. microarrays), RNA-seq data analysis pipelines, and feature levels (gene vs. transcript vs. exon-junction level) do not significantly affect performances of the models.

Conclusions

We demonstrate that RNA-seq outperforms microarrays in determining the transcriptomic characteristics of cancer, while RNA-seq and microarray-based models perform similarly in clinical endpoint prediction. Our findings may be valuable to guide future studies on the development of gene expression-based predictive models and their implementation in clinical practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0694-1) contains supplementary material, which is available to authorized users.

Blood sampling via a peripheral artery catheter decreases cerebral oxygenation index in very low-birthweight infants

AIM

This study evaluated the impact of blood sampling via peripheral arterial catheters on cerebral oxygenation and blood volume as a function of blood sampling velocity.

METHODS

Near-infrared spectroscopy was applied to 20 very low-birthweight infants during peripheral arterial blood sampling. Changes in cerebral oxygenated, deoxygenated and total haemoglobin, cerebral blood volume and cerebral oxygenation index were recorded. Heart rate and oxygen saturation were measured continuously. To assess the impact of blood sampling velocity, both fast 40-sec and slow 70-sec sampling procedures were performed in a crossover study design, in which the order of sampling velocities was randomised for each patient.

RESULTS

Both fast and slow blood sampling procedures resulted in a significant decrease in cerebral oxygenation index (fast, p = 0.002, slow, p = 0.008), and an increase in mean heart rate (both p = 0.02) and mean blood pressure (p = 0.02 and 0.04). Oxygenated and total haemoglobin and cerebral blood volume only decreased significantly after slow blood sampling (p < 0.001).

CONCLUSION

Blood sampling from peripheral arterial catheters leads to significant fluctuations in cerebral oxygenation independent of the sampling velocity. Changes are comparable to those reported from umbilical blood sampling. We advise that blood sampling should be restricted as much as possible.

FOXP1 inhibits cell growth and attenuates tumorigenicity of neuroblastoma

BACKGROUND

Segmental genomic copy number alterations, such as loss of 11q or 3p and gain of 17q, are well established markers of poor outcome in neuroblastoma, and have been suggested to comprise tumor suppressor genes or oncogenes, respectively. The gene forkhead box P1 (FOXP1) maps to chromosome 3p14.1, a tumor suppressor locus deleted in many human cancers including neuroblastoma. FoxP1 belongs to a family of winged-helix transcription factors that are involved in processes of cellular proliferation, differentiation and neoplastic transformation.

METHODS

Microarray expression profiles of 476 neuroblastoma specimens were generated and genes differentially expressed between favorable and unfavorable neuroblastoma were identified. FOXP1 expression was correlated to clinical markers and patient outcome. To determine whether hypermethylation is involved in silencing of FOXP1, methylation analysis of the 5' region of FOXP1 in 47 neuroblastomas was performed. Furthermore, FOXP1 was re-expressed in three neuroblastoma cell lines to study the effect of FOXP1 on growth characteristics of neuroblastoma cells.

RESULTS

Low expression of FOXP1 is associated with markers of unfavorable prognosis like stage 4, age >18 months and MYCN amplification and unfavorable gene expression-based classification (P < 0.001 each). Moreover, FOXP1 expression predicts patient outcome accurately and independently from well-established prognostic markers. Array-based CGH analysis of 159 neuroblastomas revealed that heterozygous loss of the FOXP1 locus was a rare event (n = 4), but if present, was associated with low FOXP1 expression. By contrast, DNA methylation analysis in 47 neuroblastomas indicated that hypermethylation is not regularly involved in FOXP1 gene silencing. Re-expression of FoxP1 significantly impaired cell proliferation, viability and colony formation in soft agar. Furthermore, induction of FOXP1 expression led to cell cycle arrest and apoptotic cell death of neuroblastoma cells.

CONCLUSIONS

Our results suggest that down-regulation of FOXP1 expression is a common event in high-risk neuroblastoma pathogenesis and may contribute to tumor progression and unfavorable patient outcome.

Revised risk estimation and treatment stratification of low- and intermediate-risk neuroblastoma patients by integrating clinical and molecular prognostic markers

PURPOSE

To optimize neuroblastoma treatment stratification, we aimed at developing a novel risk estimation system by integrating gene expression-based classification and established prognostic markers.

EXPERIMENTAL DESIGN

Gene expression profiles were generated from 709 neuroblastoma specimens using customized 4 × 44 K microarrays. Classification models were built using 75 tumors with contrasting courses of disease. Validation was performed in an independent test set (n = 634) by Kaplan-Meier estimates and Cox regression analyses.

RESULTS

The best-performing classifier predicted patient outcome with an accuracy of 0.95 (sensitivity, 0.93; specificity, 0.97) in the validation cohort. The highest potential clinical value of this predictor was observed for current low-risk patients [5-year event-free survival (EFS), 0.84 ± 0.02 vs. 0.29 ± 0.10; 5-year overall survival (OS), 0.99 ± 0.01 vs. 0.76 ± 0.11; both P < 0.001] and intermediate-risk patients (5-year EFS, 0.88 ± 0.06 vs. 0.41 ± 0.10; 5-year OS, 1.0 vs. 0.70 ± 0.09; both P < 0.001). In multivariate Cox regression models for low-risk/intermediate-risk patients, the classifier outperformed risk assessment of the current German trial NB2004 [EFS: hazard ratio (HR), 5.07; 95% confidence interval (CI), 3.20-8.02; OS: HR, 25.54; 95% CI, 8.40-77.66; both P < 0.001]. On the basis of these findings, we propose to integrate the classifier into a revised risk stratification system for low-risk/intermediate-risk patients. According to this system, we identified novel subgroups with poor outcome (5-year EFS, 0.19 ± 0.08; 5-year OS, 0.59 ± 0.1), for whom we propose intensified treatment, and with beneficial outcome (5-year EFS, 0.87 ± 0.05; 5-year OS, 1.0), who may benefit from treatment de-escalation.

CONCLUSIONS

Combination of gene expression-based classification and established prognostic markers improves risk estimation of patients with low-risk/intermediate-risk neuroblastoma. We propose to implement our revised treatment stratification system in a prospective clinical trial.

High rate of symptomatic cytomegalovirus infection in extremely low gestational age preterm infants of 22-24 weeks' gestation after transmission via breast milk

BACKGROUND

Very immature preterm infants are at risk of developing symptomatic or severe infection if cytomegalovirus is transmitted via breast milk. It is still a matter of debate whether human cytomegalovirus (HCMV) infection may lead to long-term sequelae.

OBJECTIVES

We hypothesized that symptomatic and severe HCMV infection transmitted via breast milk affects extremely immature infants at a very high rate.

METHODS

In 2012, untreated breast milk was fed to extremely low birth weight infants after parental informed consent was obtained. We retrospectively analyzed data on HCMV infection of infants born in 2012 between 22 and 24 weeks of gestation.

RESULTS

17 infants were born to HCMV IgG-seropositive mothers. 11 (65%) of these were diagnosed with symptomatic infection. In all cases, thrombocytopenia was the reason to analyze the infant's urine. HCMV infection was diagnosed at a median time of 12 weeks after birth. In 5 (45%) infants, thrombocytopenia was the only symptom and resolved without antiviral therapy or platelet transfusion. 6 (55%) infants developed sepsis-like disease with mildly elevated CRP values and showed signs of respiratory failure. 3 (27%) were able to be stabilized on CPAP, 3 (27%) had to be intubated and mechanically ventilated. 4 children were treated with ganciclovir and/or valganciclovir. 55% failed otoacoustic emissions and/or automated auditory brainstem response testing at discharge.

CONCLUSIONS

In very immature infants born at the border of viability and suffering from multiple preexisting problems, HCMV infection may trigger a severe deterioration of the clinical course.

Observations on the effects of inhaled isoflurane in long-term sedation of critically Ill children using a modified AnaConDa©-system

Long-term intravenous sedation may present problems due to dependence and side effects. Medical records of children who were administered isoflurane were reviewed. 15 patients (9 boys, 6 girls) with a mean age of 11.8 month (+2.4) were analysed.Analgesia and sedation was given in mean 9.7+1.1 days before commencing inhalation using a modified application device (AnaConDa©). Administration was given over a period of 7.2+1.4 days. Depth of sedation was monitored by using Comfort- and Hartwig-scores. Observations included continuous monitoring of heart-rate, pulse oxymetry, blood pressure and cerebral tissue oxygenation.Within 4 h post administration of isoflurane a satisfactory increase in the depth of sedation was seen and kept till extubation. 6/15 patients received tracheostomies during the observation period. None of the patients observed suffered life-critical events of the modified application of isoflurane proceeded without complications. Ketamine and clonidine infusion rates were significantly reduced (p<0.005) as well as the use and overall infusion rate of midazolam, γ-hydroxy butyrate, fentanyl and morphine (p<0.05).Isoflurane inhalation may provide an additional option for long-term sedation in a specific group of critically ill infants but neurodegenerative toxic effects will have to be taken into account when using volatile anesthetics at any time during infancy.

Hox-C9 activates the intrinsic pathway of apoptosis and is associated with spontaneous regression in neuroblastoma

Neuroblastoma is an embryonal malignancy of the sympathetic nervous system. Spontaneous regression and differentiation of neuroblastoma is observed in a subset of patients, and has been suggested to represent delayed activation of physiologic molecular programs of fetal neuroblasts. Homeobox genes constitute an important family of transcription factors, which play a fundamental role in morphogenesis and cell differentiation during embryogenesis. In this study, we demonstrate that expression of the majority of the human HOX class I homeobox genes is significantly associated with clinical covariates in neuroblastoma using microarray expression data of 649 primary tumors. Moreover, a HOX gene expression-based classifier predicted neuroblastoma patient outcome independently of age, stage and MYCN amplification status. Among all HOX genes, HOXC9 expression was most prominently associated with favorable prognostic markers. Most notably, elevated HOXC9 expression was significantly associated with spontaneous regression in infant neuroblastoma. Re-expression of HOXC9 in three neuroblastoma cell lines led to a significant reduction in cell viability, and abrogated tumor growth almost completely in neuroblastoma xenografts. Neuroblastoma growth arrest was related to the induction of programmed cell death, as indicated by an increase in the sub-G1 fraction and translocation of phosphatidylserine to the outer membrane. Programmed cell death was associated with the release of cytochrome c from the mitochondria into the cytosol and activation of the intrinsic cascade of caspases, indicating that HOXC9 re-expression triggers the intrinsic apoptotic pathway. Collectively, our results show a strong prognostic impact of HOX gene expression in neuroblastoma, and may point towards a role of Hox-C9 in neuroblastoma spontaneous regression.

Hemolytic anemia and methemoglobinemia in a preterm baby as a complication of antenatal intraamnial injection of toluidine blue

A late preterm infant was born 4.5 h after intraamniotic injection of 90 mg of Toluidine blue to confirm premature rupture of membranes. Due to the fetal exposition to the dye, the entire body of the patient was blue stained and the baby suffered from methemoglobinemia, Heinz' body positive hemolytic anemia and hyperbilirubinaemia requiring exchange transfusion. These complications underline that antenatal exposition of toluidine blue may result in considerable postnatal infant morbidity. Therefore intraamniotic application of toluidine blue should be discouraged.

Clinical significance of tumor-associated inflammatory cells in metastatic neuroblastoma

PURPOSE

Children diagnosed at age ≥ 18 months with metastatic MYCN-nonamplified neuroblastoma (NBL-NA) are at high risk for disease relapse, whereas those diagnosed at age < 18 months are nearly always cured. In this study, we investigated the hypothesis that expression of genes related to tumor-associated inflammatory cells correlates with the observed differences in survival by age at diagnosis and contributes to a prognostic signature.

METHODS

Tumor-associated macrophages (TAMs) in localized and metastatic neuroblastomas (n = 71) were assessed by immunohistochemistry. Expression of 44 genes representing tumor and inflammatory cells was quantified in 133 metastatic NBL-NAs to assess age-dependent expression and to develop a logistic regression model to provide low- and high-risk scores for predicting progression-free survival (PFS). Tumors from high-risk patients enrolled onto two additional studies (n = 91) served as independent validation cohorts.

RESULTS

Metastatic neuroblastomas had higher infiltration of TAMs than locoregional tumors, and metastatic tumors diagnosed in patients at age ≥ 18 months had higher expression of inflammation-related genes than those in patients diagnosed at age < 18 months. Expression of genes representing TAMs (CD33/CD16/IL6R/IL10/FCGR3) contributed to 25% of the accuracy of a novel 14-gene tumor classification score. PFS at 5 years for children diagnosed at age ≥ 18 months with NBL-NA with a low- versus high-risk score was 47% versus 12%, 57% versus 8%, and 50% versus 20% in three independent clinical trials, respectively.

CONCLUSION

These data suggest that interactions between tumor and inflammatory cells may contribute to the clinical metastatic neuroblastoma phenotype, improve prognostication, and reveal novel therapeutic targets.

Identification of ALK germline mutation (3605delG) in pediatric anaplastic medulloblastoma

The anaplastic lymphoma kinase (ALK) gene has been found either rearranged or mutated in several neoplasms such as anaplastic large-cell lymphoma, non-small-cell lung cancer, neuroblastoma and anaplastic thyroid cancer. Medulloblastoma (MB) is an embryonic pediatric cancer arising from nervous system, a tissue in which ALK is expressed during embryonic development. We performed an ALK mutation screening in 52 MBs and we found a novel heterozygous germline deletion of a single base in exon 23 (3605delG) in a case with marked anaplasia. This G deletion results in a frameshift mutation producing a premature stop codon in exon 25 of ALK tyrosine kinase domain. We also screened three human MB cell lines without finding any mutation of ALK gene. Quantitative expression analysis of 16 out of 52 samples showed overexpression of ALK mRNA in three MBs. In the present study, we report the first mutation of ALK found in MB. Moreover, a deletion of ALK gene producing a stop codon has not been detected in human tumors up to now. Further investigations are now required to elucidate whether the truncated form of ALK may have a role in signal transduction.

Age-dependent accumulation of genomic aberrations and deregulation of cell cycle and telomerase genes in metastatic neuroblastoma

About 50% of children with neuroblastoma (NB) show a metastatic disease and have a poor prognosis. However, disease progression is greatly variable and depends on patients' age and MYCN oncogene amplification. To investigate the role of patients' age in tumor aggressiveness, we performed array-CGH and gene expression profiles of three groups (G) of metastatic NBs: G1, stage 4S patients and MYCN single copy (MYCN-) tumors; G2, stage 4 patients, ≤ 18 months of age, MYCN- tumors and favorable outcome and G3, Stage 4 patients, ≥ 19 months with unfavorable outcome. G1 was characterized by numerical aberrations prevalently; on the contrary, all G3 tumors had structural rearrangements, whereas G2 showed an intermediate pattern. The average of numerical alterations decreased significantly from G1 to G2 to G3 (p < 0.01). Contrarily, the number of structural aberrations increased from G1 to G2 to G3 (p < 2.35 E-05). Noteworthy, G3/MYCN- NBs were characterized by several complex intrachromosome rearrangements. Expression analysis of the three groups showed significant differences in genes of Rho and Ras signaling pathways, development and adhesion, cell cycle regulation and telomerase activity. Accumulation of structural alterations increased with patients' age and was associated with a more aggressive disease. Abnormal expression of genes involved in cell cycle and telomerase in G3 may be responsible for the genomic instability in this cohort of patients. The higher DNA instability observed in G3/MYCN- NBs than in MYCN-amplified G3 may also explain why patients ≥ 19 months have a poor outcome independently by MYCN status.

A three-gene expression signature model for risk stratification of patients with neuroblastoma

PURPOSE

Neuroblastoma is an embryonal tumor with contrasting clinical courses. Despite elaborate stratification strategies, precise clinical risk assessment still remains a challenge. The purpose of this study was to develop a PCR-based predictor model to improve clinical risk assessment of patients with neuroblastoma.

EXPERIMENTAL DESIGN

The model was developed using real-time PCR gene expression data from 96 samples and tested on separate expression data sets obtained from real-time PCR and microarray studies comprising 362 patients.

RESULTS

On the basis of our prior study of differentially expressed genes in favorable and unfavorable neuroblastoma subgroups, we identified three genes, CHD5, PAFAH1B1, and NME1, strongly associated with patient outcome. The expression pattern of these genes was used to develop a PCR-based single-score predictor model. The model discriminated patients into two groups with significantly different clinical outcome [set 1: 5-year overall survival (OS): 0.93 ± 0.03 vs. 0.53 ± 0.06, 5-year event-free survival (EFS): 0.85 ± 0.04 vs. 0.042 ± 0.06, both P < 0.001; set 2 OS: 0.97 ± 0.02 vs. 0.61 ± 0.1, P = 0.005, EFS: 0.91 ± 0.8 vs. 0.56 ± 0.1, P = 0.005; and set 3 OS: 0.99 ± 0.01 vs. 0.56 ± 0.06, EFS: 0.96 ± 0.02 vs. 0.43 ± 0.05, both P < 0.001]. Multivariate analysis showed that the model was an independent marker for survival (P < 0.001, for all). In comparison with accepted risk stratification systems, the model robustly classified patients in the total cohort and in different clinically relevant risk subgroups.

CONCLUSION

We propose for the first time in neuroblastoma, a technically simple PCR-based predictor model that could help refine current risk stratification systems.

Hypothalamic JNK1 and IKKβ activation and impaired early postnatal glucose metabolism after maternal perinatal high-fat feeding

Hypothalamic inflammation has been demonstrated to be an important mechanism in the pathogenesis of obesity-induced type 2 diabetes mellitus. Feeding pregnant and lactating rodents a diet rich in saturated fatty acids has consistently been shown to predispose the offspring for the development of obesity and impaired glucose metabolism. However, hypothalamic inflammation in the offspring has not been addressed as a potential underlying mechanism. In this study, virgin female C57BL/6 mice received high-fat feeding starting at conception until weaning of the offspring at postnatal d 21. The offspring developed increased body weight, body fat content, and serum leptin concentrations during the nursing period. Analysis of hypothalamic tissue of the offspring at postnatal d 21 showed up-regulation of several members of the toll-like receptor 4 signaling cascade and subsequent activation of c-Jun N-terminal kinase 1 and IκB kinase-β inflammatory pathways. Interestingly, glucose tolerance testing in the offspring revealed signs of impaired glucose tolerance along with increased hepatic expression of the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase. In addition, significantly increased hepatic and pancreatic PGC1α expression suggests a role for sympathetic innervation in mediating the effects of hypothalamic inflammation to the periphery. Taken together, our data indicate an important role for hypothalamic inflammation in the early pathogenesis of glucose intolerance after maternal perinatal high-fat feeding.

Maximum predictive power of the microarray-based models for clinical outcomes is limited by correlation between endpoint and gene expression profile

Background

Microarray data have been used for gene signature selection to predict clinical outcomes. Many studies have attempted to identify factors that affect models' performance with only little success. Fine-tuning of model parameters and optimizing each step of the modeling process often results in over-fitting problems without improving performance.

Results

We propose a quantitative measurement, termed consistency degree, to detect the correlation between disease endpoint and gene expression profile. Different endpoints were shown to have different consistency degrees to gene expression profiles. The validity of this measurement to estimate the consistency was tested with significance at a p-value less than 2.2e-16 for all of the studied endpoints. According to the consistency degree score, overall survival milestone outcome of multiple myeloma was proposed to extend from 730 days to 1561 days, which is more consistent with gene expression profile.

Conclusion

For various clinical endpoints, the maximum predictive powers of different microarray-based models are limited by the correlation between endpoint and gene expression profile of disease samples as indicated by the consistency degree score. In addition, previous defined clinical outcomes can also be reassessed and refined more coherent according to related disease gene expression profile. Our findings point to an entirely new direction for assessing the microarray-based predictive models and provide important information to gene signature based clinical applications.

Mothers seeing their VLBW infants within 3 h after birth are more likely to establish a secure attachment behavior: evidence of a sensitive period with preterm infants?

OBJECTIVE

Close contact of mother and child in the first hours after birth is essential for the establishment of a secure attachment behavior in term infants. To date, studies investigating whether a 'sensitive period' also exists for very low birth weight (VLBW) preterm infants are lacking.

STUDY DESIGN

Attachment patterns of 62 VLBW infants were assessed using the 'strange situation' setting and correlated with the time mothers saw their child for the first time. Furthermore, maternal and infant covariates possibly influencing the attachment behavior were analyzed. As maternal factors the mother's age, social status and pregnancy history were recorded and at three time points (time 1, 2 and 3 (t-1, t-2 and t-3)), a semi-structured interview, a depression and a social support questionnaire were performed. As infant factors neonatal basic data, ventilation time and length of hospital stay were recorded. Disease severity was scored using the clinical risk index for babies, score for neonatal acute physiology (SNAP), SNAP perinatal extension and nursery neurobiological risk score. At time points t-2 and t-3, the infants were examined using the second edition of Bayley scales of infant development.

RESULTS

In all, 53.2% of the children showed a secure, 33.9% an insecure-avoidant, 3.2% an insecure-ambivalent and 9.7% an insecure-disorganized attachment behavior. Preterm infants whose mothers had seen them within 3 h after birth had a higher rate of secure attachment than preterm infants with no early contact (76 versus 41%, P=0.009). Firstborns showed a significantly higher rate of insecure attachment behavior (93 versus 67%, P=0.01). No influence on attachment behavior was shown for any other maternal or infant factor.

CONCLUSIONS

Our results support the hypothesis that the first hours after birth are a 'sensitive period' for the development of attachment behavior in VLBW infants. When a mother is enabled to see her infant shortly after birth, the 'sensitive period' right after birth may be used to help forming an important basis for the secure attachment of the preterm infant.

Chromosome 9q and 16q loss identified by genome-wide pooled-analysis are associated with tumor aggressiveness in patients with classic medulloblastoma

Medulloblastoma (MB) is one of the most aggressive pediatric brain tumor. We report genome-wide pooled-analysis of classic MB variant of patients over 3 years of age at diagnosis. We combined array comparative genomic hybridization (aCGH) results from experimental analysis (31 cases) with two public databases (55 cases) in a final evaluation of 86 MBs. The most common chromosome structural aberrations were gains of 17q (45.3%), 1q (22.1%), and losses of 8p (15.1%), 10q (19.8%), 17p (37.2%), and 16q (16.3%). Isochromome (17q) was observed in 29.1% MBs. A significant association between poor patients survival and losses of 9q (p < 0.0023), 10q (p < 0.012), and 16q (p < 0.036) was observed. Univariate analysis showed association of 9q loss (p < 0.008) and 16q loss (p = 0.05) with adverse overall survival (OS). Chromosome 6 monosomy was a protective event although statistically borderline (p = 0.066). After adjusting for confounding factors, a poor OS was found for patients whose tumor has 9q loss [hazard ratio (HR) = 3.97; p < 0.006) or 16q loss (HR = 2.41; p = 0.038). Our results highlight the importance of genomic studies in different MB histological variants and indicate a genotype-phenotype correlation.

Angiotensin II receptor blocker induced fetopathy: 7 cases

BACKGROUND

During a period of 12 months 7 newborns with a partially severe fetopathy caused most probably by maternal sartan-intake in pregnancy were treated in 5 German teaching hospitals. Sartans antagonize the effect of angiotensin II at the AT1-receptor and are used to treat arterial hypertension.

METHOD

We presented 2 cases at the yearly GNPI meeting 2010 and we were informed about similar cases in other German teaching hospitals which we brought together in this publication.

RESULTS

In the presented cases, maternal sartan intake was noticed at different times in pregnancy and was in part discontinued some weeks before delivery. In all pregnancies oligohydramnios was present and fetal kidneys displayed a hyperechogenic structure on ultrasound. The newborns' postnatal course varied: oligohydramnios sequence with lung hypoplasia, arterial hypotension and renal insufficiency were the predominant problems of the first days of life. The majority (4/7) of infants did not survive this period, in other cases there was a complete (1/7) recovery of renal function whereas others survived with renal impairment (2/7), in part requiring chronic dialysis. Further distinctive features seen frequently were disturbances of cranial ossification and flaccid paralysis of hands and feet with deviations as well as sensorineural hearing loss.

CONCLUSION

These case reports again underline the hazardousness of maternal sartan intake with potential fatal outcome for the newborn. Though the use of sartans in pregnancy is contraindicated and several case reports of sartan induced fetopathies exist, the risk of sartan treatment generally seems to be underestimated.

Life-threatening hypernatremic dehydration in a 7-week-old exclusively breastfed infant as a cause of a decline in breastmilk volume and parental language barriers in a North African family

Breast-feeding is regarded as the most appropriate source of nutrition for healthy, full-term newborns and infants. Here, we present the case of a full-term, seven week old male infant who was exclusively breast-fed but who developed severe hypernatremic dehydration as a result of declined breast milk volume that was not recognized by the parents. In order to prevent serious therapy-associated side effects due to rapid rehydration, we performed a rehydration regime providing a slow decrease of serum sodium levels by carefully infusing hypertonic saline solution. Following this approach, the patient could be discharged without any noticeable disorder. As the incidence of breast-feeding associated hypernatremic dehydration in the developed countries is increasing, strategies of prevention are discussed.

Comparison of performance of one-color and two-color gene-expression analyses in predicting clinical endpoints of neuroblastoma patients

Microarray-based prediction of clinical endpoints may be performed using either a one-color approach reflecting mRNA abundance in absolute intensity values or a two-color approach yielding ratios of fluorescent intensities. In this study, as part of the MAQC-II project, we systematically compared the classification performance resulting from one- and two-color gene-expression profiles of 478 neuroblastoma samples. In total, 196 classification models were applied to these measurements to predict four clinical endpoints, and classification performances were compared in terms of accuracy, area under the curve, Matthews correlation coefficient and root mean-squared error. Whereas prediction performance varied with distinct clinical endpoints and classification models, equivalent performance metrics were observed for one- and two-color measurements in both internal and external validation. Furthermore, overlap of selected signature genes correlated inversely with endpoint prediction difficulty. In summary, our data strongly substantiate that the choice of platform is not a primary factor for successful gene expression based-prediction of clinical endpoints.

Prognostic impact of gene expression-based classification for neuroblastoma

PURPOSE

To evaluate the impact of a predefined gene expression-based classifier for clinical risk estimation and cytotoxic treatment decision making in neuroblastoma patients.

PATIENTS AND METHODS

Gene expression profiles of 440 internationally collected neuroblastoma specimens were investigated by microarray analysis, 125 of which were examined prospectively. Patients were classified as either favorable or unfavorable by a 144-gene prediction analysis for microarrays (PAM) classifier established previously on a separate set of 77 patients. PAM classification results were compared with those of current prognostic markers and risk estimation strategies.

RESULTS

The PAM classifier reliably distinguished patients with contrasting clinical courses (favorable [n = 249] and unfavorable [n = 191]; 5-year event free survival [EFS] 0.84 +/- 0.03 v 0.38 +/- 0.04; 5-year overall survival [OS] 0.98 +/- 0.01 v 0.56 +/- 0.05, respectively; both P < .001). Moreover, patients with divergent outcome were robustly discriminated in both German and international cohorts and in prospectively analyzed samples (P <or= .001 for both EFS and OS for each). In subgroups with clinical low-, intermediate-, and high-risk of death from disease, the PAM predictor significantly separated patients with divergent outcome (low-risk 5-year OS: 1.0 v 0.75 +/- 0.10, P < .001; intermediate-risk: 1.0 v 0.82 +/- 0.08, P = .042; and high-risk: 0.81 +/- 0.08 v 0.43 +/- 0.05, P = .001). In multivariate Cox regression models based on both EFS and OS, PAM was a significant independent prognostic marker (EFS: hazard ratio [HR], 3.375; 95% CI, 2.075 to 5.492; P < .001; OS: HR, 11.119, 95% CI, 2.487 to 49.701; P < .001). The highest potential clinical impact of the classifier was observed in patients currently considered as non-high-risk (n = 289; 5-year EFS: 0.87 +/- 0.02 v 0.44 +/- 0.07; 5-year OS: 1.0 v 0.80 +/- 0.06; both P < .001).

CONCLUSION

Gene expression-based classification using the 144-gene PAM predictor can contribute to improved treatment stratification of neuroblastoma patients.

Accurate outcome prediction in neuroblastoma across independent data sets using a multigene signature

PURPOSE

Reliable prognostic stratification remains a challenge for cancer patients, especially for diseases with variable clinical course such as neuroblastoma. Although numerous studies have shown that outcome might be predicted using gene expression signatures, independent cross-platform validation is often lacking.

EXPERIMENTAL DESIGN

Using eight independent studies comprising 933 neuroblastoma patients, a prognostic gene expression classifier was developed, trained, tested, and validated. The classifier was established based on reanalysis of four published studies with updated clinical information, reannotation of the probe sequences, common risk definition for training cases, and a single method for gene selection (prediction analysis of microarray) and classification (correlation analysis).

RESULTS

Based on 250 training samples from four published microarray data sets, a correlation signature was built using 42 robust prognostic genes. The resulting classifier was validated on 351 patients from four independent and unpublished data sets and on 129 remaining test samples from the published studies. Patients with divergent outcome in the total cohort, as well as in the different risk groups, were accurately classified (log-rank P < 0.001 for overall and progression-free survival in the four independent data sets). Moreover, the 42-gene classifier was shown to be an independent predictor for survival (odds ratio, >5).

CONCLUSION

The strength of this 42-gene classifier is its small number of genes and its cross-platform validity in which it outperforms other published prognostic signatures. The robustness and accuracy of the classifier enables prospective assessment of neuroblastoma patient outcome. Most importantly, this gene selection procedure might be an example for development and validation of robust gene expression signatures in other cancer entities.

Predicting outcomes for children with neuroblastoma using a multigene-expression signature: a retrospective SIOPEN/COG/GPOH study

BACKGROUND

More accurate prognostic assessment of patients with neuroblastoma is required to better inform the choice of risk-related therapy. The aim of this study is to develop and validate a gene-expression signature to improve outcome prediction.

METHODS

59 genes were selected using an innovative data-mining strategy, and were profiled in the largest neuroblastoma patient series (n=579) to date using real-time quantitative PCR starting from only 20 ng of RNA. A multigene-expression signature was built using 30 training samples, tested on 313 test samples, and subsequently validated in a blind study on an independent set of 236 tumours.

FINDINGS

The signature has a performance, sensitivity, and specificity of 85.4% (95% CI 77.7-93.2), 84.4% (66.5-94.1), and 86.5% (81.1-90.6), respectively, to predict patient outcome. Multivariate analysis indicates that the signature is a significant independent predictor of overall survival and progression-free survival after controlling for currently used risk factors: patients with high molecular risk have a higher risk of death from disease and higher risk of relapse or progression than patients with low molecular risk (odds ratio 19.32 [95% CI 6.50-57.43] and 3.96 [1.97-7.97] for overall survival and progression-free survival, respectively, both p<0.0001). Patients at an increased risk of an adverse outcome can also be identified in the current treatment groups, showing the potential of this signature for improved clinical management. These results were confirmed in the validation study, in which the signature was also independently statistically significant in a model adjusted for MYCN status, age, International Neuroblastoma Staging System stage, ploidy, International Neuroblastoma Pathology Classification grade of differentiation, and mitosis karyorrhexis index (odds ratios between 4.81 and 10.53 depending on the model for overall survival and 3.68 [95% CI 2.01-6.71] for progression-free survival).

INTERPRETATION

The 59-gene expression signature is an accurate predictor of outcome in patients with neuroblastoma. The signature is an independent risk predictor, identifying patients with an increased risk of poor outcome in the current clinical-risk groups. The method and signature is suitable for routine laboratory testing, and should be evaluated in prospective studies.

FUNDING

The Belgian Foundation Against Cancer, the Children Cancer Fund Ghent, the Belgian Society of Paediatric Haematology and Oncology, the Belgian Kid's Fund and the Fondation Nuovo-Soldati (JV), the Fund for Scientific Research Flanders (KDP, JH), the Fund for Scientific Research Flanders, the Institute for the Promotion of Innovation by Science and Technology in Flanders, Strategisch basisonderzoek, the Fondation Fournier Majoie pour l'Innovation, the Instituto Carlos III, the Italian Neuroblastoma Foundation, the European Community under the FP6, and the Belgian programme of Interuniversity Poles of Attraction.

Molecular characterization and classification of neuroblastoma

For many decades, neuroblastoma has remained a challenging disease for both clinicians and researchers. Now, techniques that efficiently specify both comprehensive genetic and gene-expression alterations of neuroblastoma tumors have provided molecular markers that indicate tumor behavior and patient outcome with very high accuracy. Once the anticipated value of these markers has been confirmed in ongoing studies, patients may profit from more accurate risk assessment by integrating these markers into clinical routine. Moreover, disclosing further tumor-initiating events, such as the recently revealed oncogenic mutations of ALK, will further promote the elucidation of the genetic etiology of the disease. Together with recent information on altered signaling pathways in aggressively growing tumors, this knowledge will help to establish therapeutic strategies specifically targeting molecular key factors of neuroblastoma tumor progression.