Identification of TP53 germline variants in pediatric patients undergoing tumor testing: strategy and prevalence.

BACKGROUND: TP53 alterations are common in certain pediatric cancers, making identification of putative germline variants through tumor genomic profiling crucial for patient management. METHODS: We analyzed TP53 alterations in 3123 tumors from 2788 pediatric patients sequenced using tumor-only or tumor-normal paired panels. Germline confirmatory testing was performed when indicated. Somatic and germline variants were classified following published guidelines. RESULTS: In 248 tumors from 222 patients, 284 Tier 1/2 TP53 sequence and small copy number variants were detected. Following germline classification, 73.9% of 142 unique variants were pathogenic/likely pathogenic (P/LP). Confirmatory testing on 118 patients revealed germline TP53 variants in 28 patients (23 P/LP and 5 uncertain significance), suggesting a minimum Li-Fraumeni syndrome (LFS) incidence of 0.8% (23/2788) in this cohort, 10.4% (23/222) in patients with TP53 variant-carrying tumors, and 19.5% (23/118) with available normal samples. About 25% (7/28) of patients with germline TP53 variants did not meet LFS diagnostic/testing criteria while 20.9% (28/134) with confirmed or inferred somatic origins did. TP53 biallelic inactivation occurred in 75% of germline carrier tumors and was also prevalent in other groups, causing an elevated tumor-observed variant allelic fraction (VAF). However, somatic evidence including low VAF correctly identified only 27.8% (25/90) of patients with confirmed somatic TP53 variants. CONCLUSION: The high incidence and variable phenotype of LFS in this cohort highlights the importance of assessing germline status of TP53 variants identified in all pediatric tumors. Without clear somatic evidence, distinguishing somatic from germline origins is challenging. Classifying germline and somatic variants should follow appropriate guidelines.

Early changes in tumor-naive cell-free methylomes and fragmentomes predict outcomes in pembrolizumab-treated solid tumors.

Early kinetics of circulating tumor DNA (ctDNA) in plasma predict response to pembrolizumab, but typically requires sequencing of matched tumor tissue or fixed gene panels. We analyzed genome-wide methylation and fragment length profiles using cell-free methylated DNA immunoprecipitation and sequencing (cfMeDIP-seq) in 204 plasma samples from 87 patients before and during treatment with pembrolizumab from a pan-cancer phase II investigator-initiated trial (INSPIRE). We trained a pan-cancer methylation signature using independent methylation array data from The Cancer Genome Atlas to quantify a cancer-specific methylation (CSM) and fragment length score (FLS) for each sample. CSM and FLS are strongly correlated with tumor-informed ctDNA levels. Early kinetics of CSM predict overall survival and progression-free survival, independently of tumor type, PD-L1, and tumor mutation burden. Early kinetics of FLS are associated with overall survival independently of CSM. Our tumor-naïve mutation-agnostic ctDNA approach integrating methylomics and fragmentomics could predict outcomes in patients treated with pembrolizumab.

Genomic profiling of pediatric hematologic malignancies and diagnosis of cancer predisposition syndromes: tumor-only versus paired tumor-normal sequencing.

Not available.

Early Cancer Detection in Li-Fraumeni Syndrome with Cell-Free DNA.

People with Li-Fraumeni syndrome (LFS) harbor a germline pathogenic variant in the TP53 tumor suppressor gene, face a near 100% lifetime risk of cancer, and routinely undergo intensive surveillance protocols. Liquid biopsy has become an attractive tool for a range of clinical applications, including early cancer detection. Here, we provide a proof-of-principle for a multimodal liquid biopsy assay that integrates a targeted gene panel, shallow whole-genome, and cell-free methylated DNA immunoprecipitation sequencing for the early detection of cancer in a longitudinal cohort of 89 LFS patients. Multimodal analysis increased our detection rate in patients with an active cancer diagnosis over uni-modal analysis and was able to detect cancer-associated signal(s) in carriers prior to diagnosis with conventional screening (positive predictive value = 67.6%, negative predictive value = 96.5%). Although adoption of liquid biopsy into current surveillance will require further clinical validation, this study provides a framework for individuals with LFS. SIGNIFICANCE: By utilizing an integrated cell-free DNA approach, liquid biopsy shows earlier detection of cancer in patients with LFS compared with current clinical surveillance methods such as imaging. Liquid biopsy provides improved accessibility and sensitivity, complementing current clinical surveillance methods to provide better care for these patients. See related commentary by Latham et al., p. 23. This article is featured in Selected Articles from This Issue, p. 5.

Current and new frontiers in hereditary cancer surveillance: Opportunities for liquid biopsy.

At least 5% of cancer diagnoses are attributed to a causal pathogenic or likely pathogenic germline genetic variant (hereditary cancer syndrome-HCS). These individuals are burdened with lifelong surveillance monitoring organs for a wide spectrum of cancers. This is associated with substantial uncertainty and anxiety in the time between screening tests and while the individuals are awaiting results. Cell-free DNA (cfDNA) sequencing has recently shown potential as a non-invasive strategy for monitoring cancer. There is an opportunity for high-yield cancer early detection in HCS. To assess clinical validity of cfDNA in individuals with HCS, representatives from eight genetics centers from across Canada founded the CHARM (cfDNA in Hereditary and High-Risk Malignancies) Consortium in 2017. In this perspective, we discuss operationalization of this consortium and early data emerging from the most common and well-characterized HCSs: hereditary breast and ovarian cancer, Lynch syndrome, Li-Fraumeni syndrome, and Neurofibromatosis type 1. We identify opportunities for the incorporation of cfDNA sequencing into surveillance protocols; these opportunities are backed by examples of earlier cancer detection efficacy in HCSs from the CHARM Consortium. We seek to establish a paradigm shift in early cancer surveillance in individuals with HCSs, away from highly centralized, regimented medical screening visits and toward more accessible, frequent, and proactive care for these high-risk individuals.

Identifying Mechanisms of Resistance by Circulating Tumor DNA in EVOLVE, a Phase II Trial of Cediranib Plus Olaparib for Ovarian Cancer at Time of PARP Inhibitor Progression.

PURPOSE: To evaluate the use of blood cell-free DNA (cfDNA) to identify emerging mechanisms of resistance to PARP inhibitors (PARPi) in high-grade serous ovarian cancer (HGSOC). EXPERIMENTAL DESIGN: We used targeted sequencing (TS) to analyze 78 longitudinal cfDNA samples collected from 30 patients with HGSOC enrolled in a phase II clinical trial evaluating cediranib (VEGF inhibitor) plus olaparib (PARPi) after progression on PARPi alone. cfDNA was collected at baseline, before treatment cycle 2, and at end of treatment. These were compared with whole-exome sequencing (WES) of baseline tumor tissues. RESULTS: At baseline (time of initial PARPi progression), cfDNA tumor fractions were 0.2% to 67% (median, 3.25%), and patients with high ctDNA levels (>15%) had a higher tumor burden (sum of target lesions; P = 0.043). Across all timepoints, cfDNA detected 74.4% of mutations known from prior tumor WES, including three of five expected BRCA1/2 reversion mutations. In addition, cfDNA identified 10 novel mutations not detected by WES, including seven TP53 mutations annotated as pathogenic by ClinVar. cfDNA fragmentation analysis attributed five of these novel TP53 mutations to clonal hematopoiesis of indeterminate potential (CHIP). At baseline, samples with significant differences in mutant fragment size distribution had shorter time to progression (P = 0.001). CONCLUSIONS: Longitudinal testing of cfDNA by TS provides a noninvasive tool for detection of tumor-derived mutations and mechanisms of PARPi resistance that may aid in directing patients to appropriate therapeutic strategies. With cfDNA fragmentation analyses, CHIP was identified in several patients and warrants further investigation.

p35 is a Crucial Player in NK-cell Cytotoxicity and TGFß-mediated NK-cell Dysfunction.

Natural killer (NK) cells are innate lymphocytes with cytotoxic activity. Understanding the factors regulating cytotoxicity is crucial for improving NK-cell adoptive therapies. Here, we studied a previously unknown role of p35 (CDK5R1), a coactivator of cyclin-dependent kinase 5 (CDK5) in NK-cell function. p35 expression was thought to be neuronal-specific and the majority of studies are still focused on neuronal cells. Here, we show that CDK5 and p35 are expressed in NK cells and are kinase-active. NK cells from p35 knockout mice were analyzed and showed significantly increased cytotoxicity against murine cancer cells, while they did not show any differences in cell numbers or maturation stages. We confirmed this using human NK cells transduced with p35 short hairpin RNA (shRNA), showing similar increase in cytotoxicity against human cancer cells. Overexpression of p35 in NK cells resulted in moderate decrease in cytotoxicity, while expressing a kinase-dead mutant of CDK5 displayed increased cytotoxicity. Together, these data suggest that p35 negatively regulates NK-cell cytotoxicity. Surprisingly, we found that TGFß, a known negative regulator of NK-cell cytotoxicity, induces p35 expression in NK cells. NK cells cultured with TGFß exhibit reduced cytotoxicity, while NK cells transduced with p35 shRNA or mutant CDK5 expression exhibited partial reversal of this inhibitory effect pointing to an interesting hypothesis that p35 plays an important role in TGFß-mediated NK-cell exhaustion. Significance: This study reports a role for p35 in NK-cell cytotoxicity and this might help to improve NK-cell adoptive therapy.

GlycoCAP: A Cell-Free, Bacterial Glycosylation Platform for Building Clickable Azido-Sialoglycoproteins.

Glycan-binding receptors known as lectins represent a class of potential therapeutic targets. Yet, the therapeutic potential of targeting lectins remains largely untapped due in part to limitations in tools for building glycan-based drugs. One group of desirable structures is proteins with noncanonical glycans. Cell-free protein synthesis systems have matured as a promising approach for making glycoproteins that may overcome current limitations and enable new glycoprotein medicines. Yet, this approach has not been applied to the construction of proteins with noncanonical glycans. To address this limitation, we develop a cell-free glycoprotein synthesis platform for building noncanonical glycans and, specifically, clickable azido-sialoglycoproteins (called GlycoCAP). The GlycoCAP platform uses an Escherichia coli-based cell-free protein synthesis system for the site-specific installation of noncanonical glycans onto proteins with a high degree of homogeneity and efficiency. As a model, we construct four noncanonical glycans onto a dust mite allergen (Der p 2): α2,3 C5-azido-sialyllactose, α2,3 C9-azido-sialyllactose, α2,6 C5-azido-sialyllactose, and α2,6 C9-azido-sialyllactose. Through a series of optimizations, we achieve more than 60% sialylation efficiency with a noncanonical azido-sialic acid. We then show that the azide click handle can be conjugated with a model fluorophore using both strain-promoted and copper-catalyzed click chemistry. We anticipate that GlycoCAP will facilitate the development and discovery of glycan-based drugs by granting access to a wider variety of possible noncanonical glycan structures and also provide an approach for functionalizing glycoproteins by click chemistry conjugation.

Integrated, Longitudinal Analysis of Cell-free DNA in Uveal Melanoma.

Uveal melanomas are rare tumors arising from melanocytes that reside in the eye. Despite surgical or radiation treatment, approximately 50% of patients with uveal melanoma will progress to metastatic disease, most often to the liver. Cell-free DNA (cfDNA) sequencing is a promising technology due to the minimally invasive sample collection and ability to infer multiple aspects of tumor response. We analyzed 46 serial cfDNA samples from 11 patients with uveal melanoma over a 1-year period following enucleation or brachytherapy (n = ∼4/patient) using targeted panel, shallow whole genome, and cell-free methylated DNA immunoprecipitation sequencing. We found detection of relapse was highly variable using independent analyses (P = 0.06-0.46), whereas a logistic regression model integrating all cfDNA profiles significantly improved relapse detection (P = 0.02), with greatest power derived from fragmentomic profiles. This work provides support for the use of integrated analyses to improve the sensitivity of circulating tumor DNA detection using multi-modal cfDNA sequencing. Significance: Here, we demonstrate integrated, longitudinal cfDNA sequencing using multi-omic approaches is more effective than unimodal analysis. This approach supports the use of frequent blood testing using comprehensive genomic, fragmentomic, and epigenomic techniques.

A low-cost recombinant glycoconjugate vaccine confers immunogenicity and protection against enterotoxigenic Escherichia coli infections in mice.

Enterotoxigenic Escherichia coli (ETEC) is the primary etiologic agent of traveler's diarrhea and a major cause of diarrheal disease and death worldwide, especially in infants and young children. Despite significant efforts over the past several decades, an affordable vaccine that appreciably decreases mortality and morbidity associated with ETEC infection among children under the age of 5 years remains an unmet aspirational goal. Here, we describe robust, cost-effective biosynthetic routes that leverage glycoengineered strains of non-pathogenic E. coli or their cell-free extracts for producing conjugate vaccine candidates against two of the most prevalent O serogroups of ETEC, O148 and O78. Specifically, we demonstrate site-specific installation of O-antigen polysaccharides (O-PS) corresponding to these serogroups onto licensed carrier proteins using the oligosaccharyltransferase PglB from Campylobacter jejuni. The resulting conjugates stimulate strong O-PS-specific humoral responses in mice and elicit IgG antibodies that possess bactericidal activity against the cognate pathogens. We also show that one of the prototype conjugates decorated with serogroup O148 O-PS reduces ETEC colonization in mice, providing evidence of vaccine-induced mucosal protection. We anticipate that our bacterial cell-based and cell-free platforms will enable creation of multivalent formulations with the potential for broad ETEC serogroup protection and increased access through low-cost biomanufacturing.

Targeting negative energy balance with calorie restriction and mitochondrial uncoupling in db/db mice.

OBJECTIVE: Calorie restriction is a first-line treatment for overweight individuals with metabolic impairments. However, few patients can adhere to long-term calorie restriction. An alternative approach to calorie restriction that also causes negative energy balance is mitochondrial uncoupling, which decreases the amount of energy that can be extracted from food. Herein we compare the metabolic effects of calorie restriction with the mitochondrial uncoupler BAM15 in the db/db mouse model of severe hyperglycemia, obesity, hypertriglyceridemia, and fatty liver. METHODS: Male db/db mice were treated with ∼50% calorie restriction, BAM15 at two doses of 0.1% and 0.2% (w/w) admixed in diet, or 0.2% BAM15 with time-restricted feeding from 5 weeks of age. Mice were metabolically phenotyped over 4 weeks with assessment of key readouts including body weight, glucose tolerance, and liver steatosis. At termination, liver tissues were analysed by metabolomics and qPCR. RESULTS: Calorie restriction and high-dose 0.2% BAM15 decreased body weight to a similar extent, but mice treated with BAM15 had far better improvement in glucose control. High-dose BAM15 treatment completely normalized fasting glucose and glucose tolerance to levels similar to lean db/+ control mice. Low-dose 0.1% BAM15 did not affect body mass but partially improved glucose tolerance to a similar degree as 50% calorie restriction. Both calorie restriction and high-dose BAM15 significantly improved hyperglucagonemia and liver and serum triglyceride levels. Combining high-dose BAM15 with time-restricted feeding to match the time that calorie restricted mice were fed resulted in the best metabolic phenotype most similar to lean db/+ controls. BAM15-mediated improvements in glucose control were associated with decreased glucagon levels and decreased expression of enzymes involved in hepatic gluconeogenesis. CONCLUSIONS: BAM15 and calorie restriction treatments improved most metabolic disease phenotypes in db/db mice. However, mice fed BAM15 had superior effects on glucose control compared to the calorie restricted group that consumed half as much food. Submaximal dosing with BAM15 demonstrated that its beneficial effects on glucose control are independent of weight loss. These data highlight the potential for mitochondrial uncoupler pharmacotherapies in the treatment of metabolic disease.

A Low-Cost, Thermostable, Cell-Free Protein Synthesis Platform for On-Demand Production of Conjugate Vaccines.

Cell-free protein synthesis systems that can be lyophilized for long-term, non-refrigerated storage and transportation have the potential to enable decentralized biomanufacturing. However, increased thermostability and decreased reaction cost are necessary for further technology adoption. Here, we identify maltodextrin as an additive to cell-free reactions that can act as both a lyoprotectant to increase thermostability and a low-cost energy substrate. As a model, we apply optimized formulations to produce conjugate vaccines for ∼$0.50 per dose after storage at room temperature (∼22 °C) or 37 °C for up to 4 weeks, and ∼$1.00 per dose after storage at 50 °C for up to 4 weeks, with costs based on raw materials purchased at the laboratory scale. We show that these conjugate vaccines generate bactericidal antibodies against enterotoxigenic Escherichia coli (ETEC) O78 O-polysaccharide, a pathogen responsible for diarrheal disease, in immunized mice. We anticipate that our low-cost, thermostable cell-free glycoprotein synthesis system will enable new models of medicine biosynthesis and distribution that bypass cold-chain requirements.

In Utero Enzyme-Replacement Therapy for Infantile-Onset Pompe's Disease.

Patients with early-onset lysosomal storage diseases are ideal candidates for prenatal therapy because organ damage starts in utero. We report the safety and efficacy results of in utero enzyme-replacement therapy (ERT) in a fetus with CRIM (cross-reactive immunologic material)-negative infantile-onset Pompe's disease. The family history was positive for infantile-onset Pompe's disease with cardiomyopathy in two previously affected deceased siblings. After receiving in utero ERT and standard postnatal therapy, the current patient had normal cardiac and age-appropriate motor function postnatally, was meeting developmental milestones, had normal biomarker levels, and was feeding and growing well at 13 months of age.

Recent Progress in the Discovery and Design of Antimicrobial Peptides Using Traditional Machine Learning and Deep Learning.

Antimicrobial resistance has become a critical global health problem due to the abuse of conventional antibiotics and the rise of multi-drug-resistant microbes. Antimicrobial peptides (AMPs) are a group of natural peptides that show promise as next-generation antibiotics due to their low toxicity to the host, broad spectrum of biological activity, including antibacterial, antifungal, antiviral, and anti-parasitic activities, and great therapeutic potential, such as anticancer, anti-inflammatory, etc. Most importantly, AMPs kill bacteria by damaging cell membranes using multiple mechanisms of action rather than targeting a single molecule or pathway, making it difficult for bacterial drug resistance to develop. However, experimental approaches used to discover and design new AMPs are very expensive and time-consuming. In recent years, there has been considerable interest in using in silico methods, including traditional machine learning (ML) and deep learning (DL) approaches, to drug discovery. While there are a few papers summarizing computational AMP prediction methods, none of them focused on DL methods. In this review, we aim to survey the latest AMP prediction methods achieved by DL approaches. First, the biology background of AMP is introduced, then various feature encoding methods used to represent the features of peptide sequences are presented. We explain the most popular DL techniques and highlight the recent works based on them to classify AMPs and design novel peptide sequences. Finally, we discuss the limitations and challenges of AMP prediction.

Integrated proteomic analysis of low-grade gliomas reveals contributions of 1p-19q co-deletion to oligodendroglioma.

Diffusely infiltrative low-grade gliomas (LGG) are primary brain tumours that arise predominantly in the cerebral hemispheres of younger adults. LGG can display either astrocytic or oligodendroglial histology and do not express malignant histological features. Vast majority of LGG are unified by IDH mutations. Other genomic features including ATRX as well as copy number status of chromosomes 1p and 19q serve to molecularly segregate this tumor group. Despite the exponential gains in molecular profiling and understanding of LGG, survival rates and treatment options have stagnated over the past few decades with few advancements. In this study, we utilize low grade glioma RNA-seq data from the Cancer Genome Atlas (TCGA-LGG) and tandem mass-spectrometry on an in-house cohort of 54 formalin-fixed paraffin-embedded (FFPE) LGG specimens to investigate the transcriptomic and proteomic profiles across the three molecular subtypes of LGG (Type I: IDH mutant - 1p19q co-deleted, Type II: IDH mutant - 1p19q retained, Type III: IDH wildtype). Within the 3 LGG subtypes, gene expression was driven heavily by IDH mutation and 1p19q co-deletion. In concordance with RNA expression, we were able to identify decreased expressions of proteins coded in 1p19q in Type I LGG. Further proteomic analysis identified 54 subtype specific proteins that were used to classify the three subtypes using a multinomial regression model (AUC = 0.911). Type I LGG were found to have increased protein expression of several metabolic proteins while Type III LGG were found to have increased immune infiltration and inflammation related proteins. Here we present the largest proteomic cohort of LGG and show that proteomic profiles can be successfully analyzed from FFPE tissues. We uncover previously known and novel subtype specific markers that are useful for the proteomic classification of LGG subtypes.

Inhibition of O-GlcNAcylation Decreases the Cytotoxic Function of Natural Killer Cells.

Natural killer (NK) cells mediate killing of malignant and virus-infected cells, a property that is explored as a cell therapy approach in the clinic. Various cell intrinsic and extrinsic factors affect NK cell cytotoxic function, and an improved understanding of the mechanism regulating NK cell function is necessary to accomplish better success with NK cell therapeutics. Here, we explored the role of O-GlcNAcylation, a previously unexplored molecular mechanism regulating NK cell function. O-GlcNAcylation is a post-translational modification mediated by O-GlcNAc transferase (OGT) that adds the monosaccharide N-acetylglucosamine to serine and threonine residues on intracellular proteins and O-GlcNAcase (OGA) that removes the sugar. We found that stimulation of NK cells with the cytokines interleukin-2 (IL-2) and IL-15 results in enhanced O-GlcNAcylation of several cellular proteins. Chemical inhibition of O-GlcNAcylation using OSMI-1 was associated with a decreased expression of NK cell receptors (NKG2D, NKG2A, NKp44), cytokines [tumor necrosis factor (TNF)-α, interferon (IFN-γ)], granulysin, soluble Fas ligand, perforin, and granzyme B in NK cells. Importantly, inhibition of O-GlcNAcylation inhibited NK cell cytotoxicity against cancer cells. However, increases in O-GlcNAcylation following OGA inhibition using an OGA inhibitor or shRNA-mediated suppression did not alter NK cell cytotoxicity. Finally, we found that NK cells pretreated with OSMI-1 to inhibit O-GlcNAcylation showed compromised cytotoxic activity against tumor cells in vivo in a lymphoma xenograft mouse model. Overall, this study provides the seminal insight into the role of O-GlcNAcylation in regulating NK cell cytotoxic function.

Ocular findings associated with FADD deficiency resemble familial exudative vitreoretinopathy.

PURPOSE: We report the first known case of eye findings associated with a Fas-associated protein with death domain (FADD) gene mutation, an exceedingly rare entity. OBSERVATIONS: A 7-year-old boy was referred for decreased vision and eye examination revealed cystoid macular edema and peripheral retinal ischemia in both eyes and progression to tractional retinal detachment in the right eye. CONCLUSIONS AND IMPORTANCE: This case suggests that baseline and annual ophthalmic screening may be beneficial in individuals with FADD mutations. However, greater documentation of cases may be necessary before deriving a clear interval screening recommendation.

A BAFF ligand-based CAR-T cell targeting three receptors and multiple B cell cancers.

B cell-activating factor (BAFF) binds the three receptors BAFF-R, BCMA, and TACI, predominantly expressed on mature B cells. Almost all B cell cancers are reported to express at least one of these receptors. Here we develop a BAFF ligand-based chimeric antigen receptor (CAR) and generate BAFF CAR-T cells using a non-viral gene delivery method. We show that BAFF CAR-T cells bind specifically to each of the three BAFF receptors and are effective at killing multiple B cell cancers, including mantle cell lymphoma (MCL), multiple myeloma (MM), and acute lymphoblastic leukemia (ALL), in vitro and in vivo using different xenograft models. Co-culture of BAFF CAR-T cells with these tumor cells results in induction of activation marker CD69, degranulation marker CD107a, and multiple proinflammatory cytokines. In summary, we report a ligand-based BAFF CAR-T capable of binding three different receptors, minimizing the potential for antigen escape in the treatment of B cell cancers.

Perceptions of Healthy Lifestyles Among Children With Complex Heart Disease and Their Caregivers.

BACKGROUND: Children with complex heart problems may be at higher risk for sedentary lifestyle morbidities than their healthy peers. This project examined perceptions, barriers, and supports that influence healthy active lifestyles among children with complex heart problems and their caregivers, to enable effective health and quality-of-life interventions. METHODS: Inductive thematic analysis was conducted of semi-structured guided discussions from 6 focus groups (young child [n = 2]; older child [n = 4]; parents of young child [n = 4]; parents of older child [n = 4]; pediatric cardiologist [n = 5]; pediatric cardiac nurse [n = 5]) and individual interviews with 7 parents, 5 parent/child dyads, 2 adults with complex heart problems, 6 pediatric cardiologists, 3 pediatric cardiac nurses, 4 pediatric cardiology mental health professionals, and 14 recreation professionals. RESULTS: Four interrelated themes were identified: (i) "It takes a village"-coordinated and collaborative interdisciplinary support; (ii) clear healthy lifestyle communication among children, families, and professionals is critically important; (iii) Ccreating supportive environments by building professional expertise; (iv) inspiring healthy lifestyles in the children's own environments. All groups identified a need to improve knowledge about childhood heart conditions among education and recreation professionals and to encourage effective communication between healthcare professionals and families. Participants indicated that these changes would support families, educators, and recreation professionals in engaging children with heart problems in healthy lifestyles in home, school, and community settings. CONCLUSIONS: Important healthy lifestyle barriers were identified within individuals and in their interactions. There is a profound need to enhance knowledge of childhood heart conditions and improve interactions among key stakeholders-children and families, educators, and recreation and healthcare professionals.

CONTEXTE: Les enfants atteints d'un trouble cardiaque complexe pourraient être exposés à un risque plus élevé d'états morbides associés à la sédentarité que leurs pairs en bonne santé. Notre projet visait à étudier auprès d'enfants atteints d'un trouble cardiaque complexe et de leurs aidants les perceptions, les obstacles et les mesures de soutien qui influent sur l'adoption d'un mode de vie actif sain, afin de mettre en place des interventions efficaces pour améliorer la santé et la qualité de vie de ces patients. MÉTHODOLOGIE: Nous avons mené une analyse thématique inductive comprenant des discussions dirigées semi-structurées auprès de six groupes (jeunes enfants [n = 2]; enfants plus âgés [n = 4]; parents de jeunes enfants [n = 4]; parents d'enfants plus âgés [n = 4]; cardiologues-pédiatres [n = 5]; infirmières en cardiologie pédiatrique [n = 5]) et des entrevues individuelles auprès de 7 parents, 5 dyades parent-enfant, 2 adultes atteints d'un trouble cardiaque complexe, 6 cardiologues-pédiatres, 3 infirmières en cardiologie pédiatrique, 4 professionnels de la santé mentale en cardiologie pédiatrique et 14 professionnels du loisir. RÉSULTATS: Nous avons dégagé quatre thèmes interreliés : i) « il faut tout un village ¼ ­ soutien interdisciplinaire coordonné et axé sur la collaboration; ii) communication claire de ce qu'est un mode de vie sain entre enfants, familles et professionnels (élément d'une importance cruciale); iii) création de milieux favorables par le développement des expertises professionnelles; iv) stimulation de l'adoption d'un mode de vie sain dans les milieux que fréquentent les enfants. Tous les groupes interrogés ont signalé la nécessité d'améliorer les connaissances des professionnels de l'éducation et du loisir quant aux problèmes cardiaques de l'enfance et d'encourager une communication efficace entre les professionnels de la santé et les familles. Les participants ont indiqué que de tels changements aideraient les familles, les enseignants et les professionnels du loisir à donner aux enfants atteints d'un trouble cardiaque la chance d'adopter un mode de vie sain à la maison, à l'école et dans la communauté. CONCLUSIONS: Des obstacles importants à l'adoption d'un mode de vie sain ont été cernés à l'échelle individuelle et sur le plan des interactions. Il existe un besoin profond de rehausser les connaissances en matière de troubles cardiaques de l'enfance et d'améliorer les interactions entre les principaux intervenants ­ les enfants et leurs familles, les enseignants et les professionnels de la santé et du loisir.

Alternative to Body Surface Area as a Solution to Correct Systematic Bias in Pediatric Echocardiography z Scores.

BACKGROUND: Z scores are the method of choice to report dimensions in pediatric echocardiography. Z scores based on body surface area (BSA) have been shown to cause systematic biases in overweight and obese children. Using aortic valve (AoV) diameters as a paradigm, the aims of this study were to assess the magnitude of z score underestimation in children with increased body mass index z score (BMI-z) and to determine if a predicting model with height and weight as independent predictors would minimise this bias. METHODS: In this multicentre, retrospective, cross-sectional study, 15,006 normal echocardiograms in healthy children 1-18 years old were analyzed. Residual associations with body size were assessed for previously published z score. BSA-based and alternate prediction models based on height and weight were developed and validated in separate training and validation samples. RESULTS: Existing BSA-based z scores incompletely adjusted for weight, BSA, and BMI-z and led to an underestimation of > 0.8 z score units in subjects with higher BMI-z compared with lean subjects. BSA-based models led to overestimation of predicted AoV diameters with increasing weight or BMI-z. Models using height and weight as independent predictors improved adjustment with body size, including in children with higher BMI-z. CONCLUSIONS: BSA-based models result in underestimation of z scores in patients with high BMI-z. Prediction models using height and weight as independent predictors minimise residual associations with body size and generate well fitted predicted values that could apply to all children, including those with low or high BMI-z.