Pediatric Research

Theme 1: Childhood asthma - a multifaceted disease.

The Generation R Study and the KinderHaven asthma clinic

Prof. dr. J.C. de Jongste and dr. L. Duijts (Erasmus MC-Sophia)

The Generation R Study is a population-based prospective cohort study from early fetal life of originally 9,778 children and their parents. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health during fetal life, childhood and adulthood in a multi-ethnic urban population. One of the main research areas is focused on Asthma, Allergy and Eczema. Main exposures of interest include environmental, endocrine, genetic and epigenetic, lifestyle related, nutritional and socio-demographic determinants. General follow-up rates until the age of 6 years exceed 80 %. Data collection in mothers, fathers and children include questionnaires, detailed physical and ultrasound examinations, behavioural observations, and biological samples. A genome and epigenome wide association screen is available in the participating children. From the age of 6 years, regular detailed hands-on assessments are performed in a dedicated research center including airway resistance (Rint) and exhaled nitric oxide, a noninvasive marker of asthmatic airway inflammation. Currently, children are aged 9 years and specific examinations include lung function using spirometry, lung structure evaluation using unique and advanced MR imaging, and allergic sensitization using skin prick tests. Eventually, results contribute to the development of novel strategies for optimizing health for children.

Main research projects that are presently being addressed are:

  • What are early life environmental factors that lead to adapted lung structure and lung function, and subsequent respiratory disease such as asthma?
  • What are genetic and epigenetic factors that lead to adapted lung structure and lung function, and subsequent respiratory disease such as asthma?
  • What are early life environmental factors leading to eczema and allergy?
  • What are genetic and epigenetic factors leading to eczema and allergy?

MSc students actively participate in one of the projects with the aim to write a paper suitable publication.

At our KinderHaven asthma and allergy clinic, highly protocolized care is provided to a large group of asthmatic and allergic children. Asthma treatment follows a step-up step down-approach depending on the level of asthma control and according to guidelines. All clinical data including assessments of asthma symptoms, lung function and airway inflammation, and all treatment decisions are accessible in the electronic patient record system of Erasmus MC and can be analyzed for scientific purposes.

Specific research questions related to asthma care at KinderHaven include:

  • How do the treatment steps as defined in guideline algorithms for childhood asthma relate to clinical asthma control?
  • Are there prognostic factors which predict a differential response in step 3 treatment (add on of long-acting beta agonists versus doubling doses of inhaled corticosteroids) in children with uncontrolled asthma on step 2 treatment?
  • Does including lung function measurements in clinical asthma care improve asthma outcomes like asthma control?
  • Can specific asthma phenotypes be validated in the ‘KinderHaven’ cohort?
  • Are there risk factors for accelerated lung function decline in children with asthma?

For a NIHES fellowship, the KinderHaven clinical databases, containing data from longitudinal follow-up in a clinical routine setting, will be used to answer selected questions.

Theme 2: Genetics and epigenetics of childhood diseases – the Generation R Study

Dr. J.F. Felix, Prof. dr. V.W.V. Jaddoe

The research on genetics and epigenetics of childhood diseases in Generation R focuses on the role of genetic and epigenetic factors in common childhood diseases and phenotypes, such as birth weight, obesity, insulin resistance and growth. For this, we use data from our genome-wide and epigenome-wide profiles, which are a unique source of information. The work in this group is often part of large-scale international collaborations. In the epigenetic studies, a particular focus is on the associations between maternal risk factors during pregnancy and epigenetic markers in children, as well as on epigenetic characteristics and their role in common childhood diseases.

Examples of projects in this theme are:

  • Maternal smoking and epigenetic markers in cord blood
  • Maternal folate levels and epigenetic markers in cord blood
  • Cord blood epigenetic markers and childhood obesity
  • Cord blood epigenetic markers and childhood growth

MSc students actively participate in one of the projects with the aim to write a paper that can be submitted for publication.

Theme 3: Pediatric emergency care

Triage and decision making in febrile children in an international study, Prof. dr. H.A. Moll, dr. R. Oostenbrink

Evidence based medicine is the standard for current clinical practice. Several clinical decision rules including triage tools for acute pediatric problems are developed, but only a few are validated. Decision rules aim to distinguish patients with severe (infectious) illnesses from patients with mild self-limiting illnesses.

The pediatric emergency department in the Erasmus MC-Sophia Children Hospital is visited by an urban, multi-ethnic population of nearly 9000 children per year: 75% is younger than 4 years of age and 50% presents with infectious diseases. Triage in the emergency department is used to prioritize patients by urgency of care. Triage aims to determine a patient’s acuity level in order to facilitate timely and effective care before their condition worsens. Currently available triage methods are predominantly based on the adult population. The Manchester Triage System is widely used in European hospitals. ,. We started an international study on the validity of the MTS in four different European settings with different healthcare systems. Effective triage aims to have low undertriage (incorrectly classified as low urgent), while limiting overtriage (incorrectly classified as high urgent). Undertriaged patients wait longer and the delay in diagnosis and treatment increases morbidity and mortality. Overtriage obstructs patient flow of the true urgent patients with consequent delays in treatment and quality of care. Therefore triage is an important tool, to manage patient flow safely at th ED.

Fever is one of the most common acute illnesses in children visiting the emergency department and constitutes a diagnostic and therapeutic dilemma for paediatricians. The causes of the fever vary from meningitis, sepsis, pneumonia and other serious bacterial infections to mild viral diseases. The challenge is to identify children with possible serious infections based on clinical symptoms and laboratory tests.

In our research we focus on the validation and modification of decision rules in the pediatric population. In this study, data on triage, initial patient evaluation, diagnostics, treatment and follow-up are collected of 100.000 children visiting emergency departments in Europe. Data collection in these settings is part of the research as participating in patient evaluation at the pediatric emergency care of the Sophia’s children’s Hospital – Erasmus MC.

Aim: The project aims to modify and validate triage for the pediatric population in order to determine the best initial management for the acutely ill child. The following research questions will be assessed:

  • What is the efficacy of the Manchester Triage System for pediatric patients in different European settings?
  • How can we modify the system for pediatric patients at the emergency department based on the international results?
  • The project subsequently focuses on the validation of prediction rules in children with fever in pediatric emergency care.

We address the following questions:

  • What is the diagnostic value of new diagnostic tests in the evaluation of children with fever in addition to clinical signs and symptoms or specific prediction rules?
  • How can we improve and reduce antibiotic use in febrile children What is the actual impact of the implementation of clinical decision rules with the use information technology (clinical decision support system) in the emergency department?

Theme 4: Biological determinants of outcome and development of targeted therapies in childhood cancer

Prof. dr. Rob Pieters, Prof. dr. Monique L. den Boer, dr. Jules Meijerink (UHD), dr. M. Fornerod (UHD), dr. Max van Noesel, dr. Ronald Stam, dr. Michel Zwaan (UHD), dr. Marry M. van den Heuvel-Eibrink (UHD)

The pediatric oncology translational research program has the following aims: 1) Developing clinically and biologically relevant classification of leukemia. Identification of molecules associated with chemotherapy resistance, and identification of new therapeutic targets as well as development of new treatment strategies for children with cancer. 2) Clinical phase I and II studies in children. (The Department of Pediatric Oncology of the Erasmus MC-Sophia Children’s Hospital is part of the European network of centers to perform these studies. The research laboratory of Pediatric Oncology is selected by the European ITCC (Innovative Therapies for Children with Cancer) network to perform the preclinical studies in especially leukemia for Europe). 3) translational research on pediatric solid tumours. 4) Early and late side effects of treatment, and palliative care. The umbrella of the research program is to develop targeted therapies for children with cancer. This should lead to more effective and less toxic treatment strategies.

For the Research Master Health Sciences & Research Master Clinical Research for Medical Students the following projects are available for NIHES students:

Subtheme 4.1. Molecular markers and drugable targets in pediatric acute leukemia

(working group leader Prof. dr. Monique L. den Boer)

For childhood ALL the cure rates are about 80%. Further optimization of therapy requires insights in the biology of leukemia cells and its microenvironment. This will lead to more specific therapies with more efficacy and less side effects. Our work focusses on the following topics:

  • improving classification of leukemia by identifying novel genetic ALL-types that are clinically relevant,
  • elucidating causes of cellular drug resistance,
  • studying the contribution of the mesenchymal niche in maintenance of leukemic cells,
  • identifying genes functionally important to viability of leukemic cells that may be targeted by specific drugs,
  • preclinical testing of the efficacy and specificity of targeted drugs (ALL xenograft mouse models).

Student project 1. In the last years we have shown that new genetic types of ALL can be identified by gene expression signatures (mRNA level) and genomics (DNA level). In ongoing studies we determine the clinical application of these genomic abnormalities, e.g. the genomic EBF1-PDGFRB fusion was found in a highly unfavorable prognostic group of BCR-ABL1-like ALL that we recently discovered by gene expression studies. In the student’s project we will characterize the genetic and molecular defects of this novel subtype aiming to point to drugable targets.

Student project 2. Besides biological variation between patients’ leukemic cells, we hypothesize that also the microenvironment in which leukemic cells reside contributes to the fate of the leukemic cell (and hence response of a patient to chemotherapy). At present, information about the bone marrow niche is lacking and therefore not used for therapeutic purposes. In the student’s project we investigate the characteristics of the mesenchymal stromal cells which are taken from patients and determine which genes may be suitable to target the nurturing stromal cells and whether treatment directed towards the stromal cells works synergistically or antagonistically with current combination chemotherapy.

Subtheme 4.2 Molecular unraveling of pediatric myeloid malignancies

(Workgroup leaders: dr. M.M. van den Heuvel-Eibrink, dr. M. Fornerod, prof. dr. C.M. Zwaan)

Although acute myeloid leukemia (AML) accounts for only 15-20% of pediatric leukemias, primary refractory and relapsed pediatric AML lead to a significant number of childhood cancer deaths. Despite the current chemotherapeutic regimens, survival rates have plateaued at 60-70% and further treatment intensification is not feasible. Thus, there is a need to develop new drugs for pediatric AML. In adult AML and myelodysplastic syndromes, epigenetic regulation, and in particular hypermethylation of relevant tumor suppressor genes have been shown to be involved in leukemogenesis.

Based on this demethylating agents have been succesfully been applied in clinical settings. Prelimary data showed that also in children with MDS hypermethylation occurs, but studies on the frequency of epigenenetic regulator gene mutations are scarce and numbers are small. This project is aimed at identifying differences in methylation patterns in pediatric AML especially focused on, MPL-RARA and AML1-ETO subgroups based on genome-wide DNA methylation profiling analysis. This, to provide the rational for treatment of pediatric AML patients with demethylating-agents and to identify novel deregulated genes in pediatric AML.

Student project 3(MDS) and 4(AML). In the current project, selected epigenetic regulator genes will be studied in a national and international collected cohort of children with MDS(n=110) as well as in the selected above mentioned selected subgroup of pediatric AMLcohort (n=500). Approval of this study and ethical committee consent has been obtained. The results may provide further evidence that epigenetic regulation is important, and that demethylating agents may be of value for children with MDS and AML. In both projects, apart from studying epigenetic mutation status, available methylation array findings on loci of interest. In PML-RARA and/or AML1-ETO patients and other AML subgroups will be validated by means of MS-PCR and bisulfite sequencing. Correlation of methylation status and expression levels of genes of interest in the different AML and MDS subgroups will be performed by comparingmethylation array data to gene expression array data and qPCR. In addition expression of the genes of interest that are regulated through methylation will be further functionally validated by means of in vitro assays using demethylating-agents.

Subtheme 4.3 Preclinical validation of drug targets for phase I and II studies in pediatric cancer

(Principal investigator prof. dr. C.M. Zwaan)

Student project 5. Most novel anti-cancer drugs introduced in pediatric oncology have first been developed in adult oncology. In order to understand their potential value for use in pediatric oncology pre-clinical studies are needed including target identification and validation in pediatric cancers. Various types of drugs are studied in our lab for this purpose, including nuclear transport inhibitors, DOT1L-inhibitors, ibrutinib, PD-1L inhibitors and various others. The results will be used to generate early clinical trials in pediatric oncology

Subtheme 4.4. Research on pediatric solid abdominal tumours.
(Pis M.M. van Noesel and M.M. van den Heuvel-Eibrink)

No projects this year

Subtheme 4.5 Early and late side effects of treatment

(Principal investigators dr. M.M. van den Heuvel-Eibrink, pediatric oncologist, dr. S. Pluijm, epidemiologist, dr. S. Neggers, Internal Medicine)

As childhood cancer survival rates are improving, the number of survivors is increasing. Therefore direct long term side effects are of great interest for identifying determinants that may lead to identification of risk groups, that may benefit from early intervention

Student project 6. Designing a prediction model for osteogenic side effects in children with acute lymphoblastic leukemia (ALL)

(Principal investigators dr. M.M. van den Heuvel-Eibrink/dr. S. Pluijm).

In a well-documented national cohort of children with ALL, bone mineral density has been studied over time(n>700 patients). Results show that osteopenia occurs in over 40% of all cases and osteoporosis in 16% of the cases. Variables that determine the risk of bone loss have now been identified, however risk models, including genetic variation as well as clinical predictors of bone loss are lacking. The current study aims to design such a model in order to identify subjects at risk and to apply intervention studies that may prevent such serious sequelae.

Student project 7. Identification of socio-economic sequelae of childhood cancer survival

(Principal investigators dr. M.M. van den Huevel-Eibrink/ dr. S. Pluijm/ dr. S. Neggers).

In a well-documented cohort of 700 long term adult childhood cancer survivors(CCS), treated in the Erasmus MC-Sophia Children’s Hospital, by questionnaires, data were collected on health status, educational level and socio-economic status, employment, problems with insurances and health perception. These data will be analysed in the current descriptive project with regard to disease type, age at diagnosis, gender, treatment, era of treatment and be linked to emotional distress status data. The results will give insight in the socio-economic sequelae long after discontinuating treatment of childhood cancer.