Clinically Complex LRBA Deficiency Due to a Founder Allele in the Georgian Jewish Population.

Pathogenic variants in LRBA, encoding the LPS Responsive Beige-Like Anchor (LRBA) protein, are responsible for recessive, early-onset hypogammaglobulinemia, severe multi-organ autoimmunity, and lymphoproliferation, with increased risk for malignancy. LRBA deficiency has a wide clinical spectrum with variable age of onset and disease severity. Three apparently unrelated patients with LRBA deficiency, of Georgian Jewish descent, were homozygous for LRBA c.6640C > T, p.R2214*, leading to a stop upstream of the LRBA BEACH domain. Despite carrying the same LRBA genotype, the three patients differed in clinical course: the first patient was asymptomatic until age 25 years; the second presented with failure to thrive at age 3 months; and the third presented at age 7 years with immune cytopenias and severe infections. Two of the patients developed malignancies: the first patient was diagnosed with recurrent Hodgkin's disease at age 36 years, and the second patient developed aggressive gastric cancer at age 15 years. Among Georgian Jews, the carrier frequency of the LRBA p.R2214* allele was 1.6% (4 of 236 Georgian Jewish controls). The allele was absent from other populations. Haplotype analysis showed a shared origin of the mutation. These three patients revealed a pathogenic LRBA founder allele in the Georgian Jewish population, support the diverse and complex clinical spectrum of LRBA deficiency, and support the possibility that LRBA deficiency predisposes to malignancy.

Treatment of severe Kaposiform lymphangiomatosis positive for NRAS mutation by MEK inhibition.

BACKGROUND: Kaposiform lymphangiomatosis (KLA) is a complex lymphatic anomaly involving most commonly the mediastinum, lung, skin and bones with few effective treatments. In recent years, RAS-MAPK pathway mutations were shown to underlie the pathogenesis of several complex lymphatic anomalies. Specifically, an activating NRAS mutation (p.Q61R) was found in the majority of KLA patients. Recent reports demonstrated promising results of treatment with the MEK inhibitor, Trametinib, in patients with complex lymphatic anomalies harboring gain of function mutations in ARAF and SOS1, as well as loss of function mutation in the CBL gene, a negative regulator of the RAS-MAPK pathway. We present a 9-year-old child with a severe case of KLA harboring the typical NRAS (p.Q61R) mutation detected by plasma-derived cell free DNA, responsive to trametinib therapy. METHODS: The NRAS somatic mutation was detected from plasma cfDNA using droplet digital PCR. Concurrent in-vitro studies of trametinib activity on mutant NRAS affected lymphatic endothelial cells were performed using a three-dimensional spheroid sprouting assay. RESULTS: Trametinib treatment lead to resolution of lifelong thrombocytopenia, improvement of pulmonary function tests and wellbeing, as well as weaning from prolonged systemic steroid treatment. Concurrent studies of mutant NRAS-expressing cells showed enhanced lymphangiogenic capacity along with over activation of the RAS-MAPK and PI3K-AKT-mTOR pathways, both reversed by trametinib. CONCLUSIONS: Trametinib treatment can substantially change the prognosis of patients with RAS pathway associated lymphatic anomalies. IMPACT: This is the first description of successful trametinib treatment of a patient with KLA harboring the most characteristic NRAS p.Q61R mutation. Treatment can significantly change the prognosis of patients with RAS pathway-associated lymphatic anomalies. We devised an in vitro model of KLA enabling a reproducible method for the continued study of disease pathogenesis. Mutated NRAS p.Q61R cells demonstrated increased lymphangiogenic capacity.

"Some things are even worse than telling a child he is going to die": Pediatric oncology healthcare professionals perspectives on communicating with children about cancer and end of life.

INTRODUCTION: This study explored pediatric oncology healthcare professionals' (HCPs) perspectives on direct communication with children with advanced disease about their disease, palliative care, and end-of-life (EOL) communication. METHODS: Forty-six pediatric oncologists, nurses, psychosocial team members, and other HCPs from six hospital centers in Israel participated in semi-structured interviews. The Grounded Theory method was used. Data were analyzed line-by-line with codes and categories developed inductively from participants' narratives. RESULTS: HCPs viewed communication about disease progression and EOL as vital because children were often aware of their prognosis, because lack of communication could lead to emotional distress, and because communication is a prerequisite for shared decision-making. HCPs identified several barriers for communication including HCP barriers (such as emotional strains, lack of training), parental barriers, guardianship law, and language and culture. HCPs also described strategies to promote EOL communication. Direct strategies include tailoring communication, allowing for silence, echoing children's questions, giving information gradually, and answering direct questions honestly. Indirect strategies included encouraging parents to talk to their children and teamwork with colleagues. CONCLUSIONS: Open communication with children who have cancer is essential. Nevertheless, multiple barriers persist. The rising accessibility of online information calls for urgent training of HCPs in communication so that children will not turn to unmediated and potentially misleading information online in the absence of HCP communication. Evidence-based effective communication training modules and emotional support should be offered to HCPs. Knowledge about children's development, age-appropriate communication, and cultural sensitivity should be included in this training.

Rivaroxaban treatment among children with cancer-associated thromboembolism: Real-world data.

This is the first study examining real-life data of pediatric cancer patients treated with rivaroxaban. Children with thrombocytopenia and high bleeding risk were excluded from previous clinical trials. Data regarding the safety and efficacy of rivaroxaban in pediatric cancer-associated thrombosis are scarce. Our case series included 16 children aged 7.5-17 years. Thrombus resolution rate in our study was comparable to results of previous studies. However, higher rates of thrombotic and bleeding complications were seen in our study as compared to previous reports, especially among patients with relapsed or refractory disease.

Oncologist conceptualizations of pediatric palliative care: challenges and definitions.

PURPOSE: Pediatric palliative care (PC) is an evolving field and involves a comprehensive approach to care of children with cancer. The goal of this paper was to explore how pediatric oncologists define, interpret, and practice pediatric palliative care in their clinical settings. METHODS: The study used the grounded theory approach to data collection and analysis. Twenty-one pediatric oncologists from six pediatric cancer centers across Israel were interviewed. Data was analyzed using line-by-line coding. RESULTS: The analysis resulted in a four-tiered conceptual model. This model included the following categories: (1) ill-defined concept; (2) philosophies of palliative care; (3) trajectory of palliative care; and (4) palliative care treatment goals. CONCLUSION: The findings illustrate the current conceptualizations of pediatric palliative care among the pediatric oncology community in Israel. The conceptual model documents their understanding of pediatric palliative care as a philosophical approach and the challenges they face in differentiating between palliative care and standard pediatric oncology care. Pediatric palliative care is a highly needed and valued sub-specialty. The findings from this study highlight the importance for its continued development in Israel, as it can reduce the suffering of children and their families. Concurrently, pediatric oncologists need to have more resources and access to explicit knowledge of the conceptual and practical aspects of both primary and specialized pediatric palliative care.

Organizational and individual barriers and facilitators to the integration of pediatric palliative care for children: A grounded theory study.

BACKGROUND: Pediatric palliative care has established benefits for children with cancer and their families. Overcoming organizational and healthcare provider barriers have been demonstrated as central for the provision of palliative care in pediatric oncology. A deeper understanding is needed of the influence of these barriers and the interactions between them, specifically in primary palliative care in hospital settings. AIM: To identify the organizational and healthcare provider barriers to the provision of primary pediatric palliative care. DESIGN: This study utilized the grounded theory method. Semi-structured interviews were conducted and analyzed line by line, using NVivo software. SETTING/PARTICIPANTS: Forty-six pediatric oncologists, nurses, psychosocial team members, and other healthcare providers from six academic hospital centers participated in the research. RESULTS: Organizational and healthcare provider factors were identified, each of which acted as both a barrier and facilitator to the provision of pediatric palliative care. Organizational barriers included lack of resources and management. Facilitators included external resources, resource management, and a palliative care center within the hospital. Individual barriers included attitudes toward palliative care among pediatric oncologists, pediatric oncologists' personalities, and the emotional burden of providing palliative care. Facilitators include dedication and commitment, initiative, and sense of meaning. Provider facilitators for palliative care had a buffering effect on organizational barriers. CONCLUSION: Organizational and healthcare provider factors influence the quality and quantity of palliative care given to children and their families. This finding has implications on interventions structured to promote primary palliative care for children, especially in healthcare systems and situations where resources are limited.

Sustained Response to Imatinib in a Pediatric Patient with Concurrent Myeloproliferative Disease and Lymphoblastic Lymphoma Associated with a CCDC88C-PDGFRB Fusion Gene.

BACKGROUND: The WHO defined myeloid and lymphoid neoplasms (MLN) with eosinophilia associated with PDGFRB, PDGFRA, FGFR1 rearrangements as a new entity in 2016. PDGFRB-rearranged MLN sensitive to imatinib were described in adult patients. We report the first pediatric patient with PDGFRB-rearranged myeloproliferative disorder associated with T-lymphoblastic lymphoma bearing the t(5; 14)(q33;q32) translocation who was successfully treated with imatinib only. Methods/Aims: Analysis of bone marrow and peripheral blood cells by fluorescent in situ hybridization identified the PDGFRB partner as CCDC88C. Whole genome sequencing of the patient's DNA identified the exact junction site, confirmed by PCR amplification and Sanger sequencing. A real-time quantitative PCR assay was designed to quantify the fused CCDC88C-PDGFRB product. RESULTS: A 2.5-year-old boy was diagnosed with myeloproliferative disorder and eosinophilia associated with lymphoblastic lymphoma both bearing the CCDC88C-PDGFRB fusion. Imatinib therapy resulted in rapid clinical, hematological, and cytogenetic response. Molecular response to treatment was monitored by a real-time PCR assay specific for the CCDC88C- PDGFRB fusion. CONCLUSION: This is the first description of MLN with eosinophilia in the pediatric age group. Response to treatment with imatinib only was monitored by specific quantitative PCR assay with sustained remission lasting 5.5 years from diagnosis.

Syncytial variant of nodular sclerosing Hodgkin lymphoma in children: A prognostic factor?

Nodular sclerosing Hodgkin lymphoma (HL) has an excellent prognosis in children. The syncytial variant (SV) of HL in adults represents a clinic pathologic entity with a worse outcome. We report the clinical features and the course of the disease of three children with refractory HL. The three patients with SV were analyzed in a retrospective multi-institutional study conducted in Israel in 51 children diagnosed with refractory or recurrent HL between 1997 and 2014. All the three children developed multiple recurrences soon after diagnosis. All three received at least three different chemotherapy combinations with autologous bone marrow transplantation for two patients, allogenic bone marrow transplantation in one, and immunotherapy in one. One patient died of disease, one is in complete response of the disease but developed a second metastatic malignancy, and one is alive without disease. This retrospective study shows that SV histology may be a prognostic factor for poor outcome in children diagnosed with HL.

Surgical Treatment of Neuroblastoma.

BACKGROUND: Neuroblastoma is the most common non-central nervous system (CNS) solid malignant tumor in children. The surgical treatment of high-risk neuroblastoma presents a challenge, and the benefits of aggressive surgical resection have been called into question. OBJECTIVES: To examine our experience with surgical resection of neuroblastoma. METHODS: We report on a retrospective chart review of our preliminary surgical experience in 25 patients with neuroblastoma who underwent surgery performed by a single surgeon at two institutions over a 3 year period. Demographic data, including stage of tumor and risk stratification, were recorded. Primary outcome was total gross resection. Patients were followed for 3 years after surgery. RESULTS: We found that 80% of the patients, including those with high-risk neuroblastoma tumors, had total gross resection of their tumor with minimal operative morbidity and no mortality; 88% had greater than 90% resection of their tumor. Overall, 3 year survival was 84% (21/25). CONCLUSIONS: Resection of neuroblastoma, even large, high-risk, bilateral tumors, was possible when performed by surgical teams with considerable experience.

Severe eosinophilia in children: a diagnostic dilemma.

The differential diagnosis of hypereosinophilia includes both primary (clonal and idiopathic) and secondary medical conditions. Here we raise the awareness of physicians to the unusual causes of hypereosinophilic states and describe the molecular assays used in the diagnosis of hypereosinophilia. Two unusual cases of hypereosinophilia in children that were initially misdiagnosed are reported. T-cell receptor gene rearrangement, skewed X inactivation, fluorescence in situ hybridization analysis, and chromosomal karyotyping were used to reach the final correct diagnosis. Both patients displayed significant eosinophilia and were initially misdiagnosed as having parasitic infection. Nonspecific T-cell clonal expansion was diagnosed in 1 patient based on the clonality of the T-cell receptor variable γ-chain and the skewed chromosome inactivation. The second patient was diagnosed with B-lineage acute lymphoblastic leukemia with a translocation (5;14) (q13;q32) that is well known to be associated with hypereosinophilia. The level of awareness to clonal expansion of WBC subsets which can cause hypereosinophilia should be high when evaluating a patient with extreme eosinophilia. Advanced molecular assays to detect clonal expansion should be used to exclude aberrant clonal processes in such patients.

Impact of COVID-19 on Lifestyle Habits and Emotional State of Childhood Cancer Survivors and Their Parents.

OBJECTIVE: The COVID-19 pandemic and associated social distancing measures affected the physical and emotional state of children and parents worldwide. Survivors of childhood cancer may be particularly vulnerable to these effects. We aimed to evaluate the lifestyle habits and emotional states of childhood cancer survivors and their parents during the COVID-19 outbreak. METHODS: Lifestyle habits and emotional distress were assessed in 43 childhood cancer survivors (aged 8-21 years) and their parents before and during the COVID-19 lockdown, using the PROMIS anxiety and depression modules and the "Mabat Youth" questionnaire. RESULTS: Most parents (80.5%) reported eating more family meals during home confinement compared to their usual routine. Patients' physical activity levels did not change significantly during confinement, leisure-related screen time nearly doubled (p < 0.001), and sleep duration increased (p = 0.006). Anxiety levels of children (p = 0.045) and parents (p = 0.02) increased during confinement compared to pre-pandemic levels, with no significant changes in depression levels. CONCLUSIONS: Contrary to concerns regarding lifestyle habits during the COVID-19 lockdown, eating behaviors of childhood cancer survivors improved, sleep duration increased, and physical activity remained unchanged. Still, screen time increased significantly. Parents of childhood cancer survivors reported higher anxiety levels for themselves and their children during home confinement. Our findings may assist medical and psycho-social teams in guiding parents of cancer survivors during similar circumstances in the future.

Embryonic pig pancreatic tissue for the treatment of diabetes in a nonhuman primate model.

Xenotransplantation of pig tissues has great potential to overcome the shortage of organ donors. One approach to address the vigorous immune rejection associated with xenotransplants is the use of embryonic precursor tissue, which induces and utilizes host vasculature upon its growth and development. Recently, we showed in mice that embryonic pig pancreatic tissue from embryonic day 42 (E42) exhibits optimal properties as a beta cell replacement therapy. We now demonstrate the proof of concept in 2 diabetic Cynomolgus monkeys, followed for 393 and 280 days, respectively. A marked reduction of exogenous insulin requirement was noted by the fourth month after transplantation, reaching complete independence from exogenous insulin during the fifth month after transplantation, with full physiological control of blood glucose levels. The porcine origin of insulin was documented by a radioimmunoassay specific for porcine C-peptide. Furthermore, the growing tissue was found to be predominantly vascularized with host blood vessels, thereby evading hyperacute or acute rejection, which could potentially be mediated by preexisting anti-pig antibodies. Durable graft protection was achieved, and most of the late complications could be attributed to the immunosuppressive protocol. While fine tuning of immune suppression, tissue dose, and implantation techniques are still required, our results demonstrate that porcine E-42 embryonic pancreatic tissue can normalize blood glucose levels in primates. Its long-term proliferative capacity, its revascularization by host endothelium, and its reduced immunogenicity, strongly suggest that this approach could offer an attractive replacement therapy for diabetes.

Anti-Tumorigenic Effect of a Novel Derivative of 2-Hydroxyoleic Acid and the Endocannabinoid Anandamide on Neuroblastoma Cells.

Modulation of the endogenous cannabinoid system has been suggested as a potential anticancer strategy. In the search for novel and less toxic therapeutic options, structural modifications of the endocannabinoid anandamide and the synthetic derivative of oleic acid, Minerval (HU-600), were done to obtain 2-hydroxy oleic acid ethanolamide (HU-585), which is an HU-600 derivative with the anandamide side chain. We showed that treatment of SK-N-SH neuroblastoma cells with HU-585 induced a better anti-tumorigenic effect in comparison to HU-600 as evidenced by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide assay, colony-forming assay, and migration assay. Moreover, HU-585 demonstrated pro-apoptotic properties shown by increased levels of activated caspase-3 following treatment and a better senescence induction effect in comparison to HU-600, as demonstrated by increased activity of lysosomal ß-galactosidase. Finally, we observed that combined treatment of HU-585 with the senolytic drugs ABT-263 in vitro, and ABT-737 in vivo resulted in enhanced anti-proliferative effects and reduced neuroblastoma xenograft growth in comparison to treatment with HU-585 alone. Based on these results, we suggest that HU-585 is a pro-apoptotic and senescence-inducing compound, better than HU-600. Hence, it may be a beneficial option for the treatment of resistant neuroblastoma especially when combined with senolytic drugs that enhance its anti-tumorigenic effects.

Mitochondrial augmentation of hematopoietic stem cells in children with single large-scale mitochondrial DNA deletion syndromes.

Patients with single large-scale mitochondrial DNA (mtDNA) deletion syndromes (SLSMDs) usually present with multisystemic disease, either as Pearson syndrome in early childhood or as Kearns-Sayre syndrome later in life. No disease-modifying therapies exist for SLSMDs. We have developed a method to enrich hematopoietic cells with exogenous mitochondria, and we treated six patients with SLSMDs through a compassionate use program. Autologous CD34+ hematopoietic cells were augmented with maternally derived healthy mitochondria, a technology termed mitochondrial augmentation therapy (MAT). All patients had substantial multisystemic disease involvement at baseline, including neurologic, endocrine, or renal impairment. We first assessed safety, finding that the procedure was well tolerated and that all study-related severe adverse events were either leukapheresis-related or related to the baseline disorder. After MAT, heteroplasmy decreased in the peripheral blood in four of the six patients. An increase in mtDNA content of peripheral blood cells was measured in all six patients 6 to 12 months after MAT as compared baseline. We noted some clinical improvement in aerobic function, measured in patients 2 and 3 by sit-to-stand or 6-min walk testing, and an increase in the body weight of five of the six patients suffering from very low body weight before treatment. Quality-of-life measurements as per caregiver assessment and physical examination showed improvement in some parameters. Together, this work lays the ground for clinical trials of MAT for the treatment of patients with mtDNA disorders.

NCAM1/FGF module serves as a putative pleuropulmonary blastoma therapeutic target.

Pleuropulmonary blastoma (PPB) is a rare pediatric lung neoplasm that recapitulates developmental pathways of early embryonic lungs. As lung development proceeds with highly regulated mesenchymal-epithelial interactions, a DICER1 mutation in PPB generates a faulty lung differentiation program with resultant biphasic tumors composed of a primitive epithelial and mesenchymal stroma with early progenitor blastomatous cells. Deciphering of PPB progression has been hampered by the difficulty of culturing PPB cells, and specifically progenitor blastomatous cells. Here, we show that in contrast with in-vitro culture, establishment of PPB patient-derived xenograft (PDX) in NOD-SCID mice selects for highly proliferating progenitor blastoma overexpressing critical regulators of lung development and multiple imprinted genes. These stem-like tumors were sequentially interrogated by gene profiling to show a FGF module that is activated alongside Neural cell adhesion molecule 1 (NCAM1). Targeting the progenitor blastoma and these transitions with an anti-NCAM1 immunoconjugate (Lorvotuzumab mertansine) inhibited tumor growth and progression providing new paradigms for PPB therapeutics. Altogether, our novel in-vivo PPB xenograft model allowed us to enrich for highly proliferating stem-like cells and to identify FGFR and NCAM1 as two key players that can serve as therapeutic targets in this poorly understood and aggressive disease.

Integration of a palliative and terminal care center into a comprehensive pediatric oncology department.

BACKGROUND: The sharp division between curative cancer therapy and palliative care results in the late introduction of palliative care and a high incidence of suffering in children with cancer. We established a Palliative Care Unit (PCU) that is fully integrated with the Pediatric Hematology Oncology Department (PHOD). We wished to explore the impact of such integrative model on patterns of hospitalizations and exposure to palliative care of pediatric oncology patients. PROCEDURES: Retrospective search of medical records of patients admitted to the PHOD since PCU establishment in 1999, and of children who died from progressive disease between 1990 and 2005 was performed. Differences in clinical and prognostic variables between PCU and non-PCU patients, and differences in location of death before and after PCU establishment were evaluated. RESULTS: The majority (59%) of patients, who were hospitalized after the PCU establishment, were hospitalized in the PCU, including 49% of the good prognosis patients and 91% of the poor prognosis patients. Poor prognosis patients were hospitalized in the PCU earlier and with higher frequency compared to children with curable disease. After PCU opening there was a significant decline in the percentage of patients who died in the general pediatric ward, hematology-oncology ward, and at home from 40%, 26% and 28% to 4%, 8%, and 16%, respectively. CONCLUSIONS: Our integrative model results in exposure of the majority of children with cancer to palliative care. For poor prognosis patients, palliative care is introduced early enough to allow gradual transition from symptom control after diagnosis to end of life care.

In Vivo Expansion of Cancer Stemness Affords Novel Cancer Stem Cell Targets: Malignant Rhabdoid Tumor as an Example.

Cancer stem cell (CSC) identification relies on transplantation assays of cell subpopulations sorted from fresh tumor samples. Here, we attempt to bypass limitations of abundant tumor source and predetermined immune selection by in vivo propagating patient-derived xenografts (PDX) from human malignant rhabdoid tumor (MRT), a rare and lethal pediatric neoplasm, to an advanced state in which most cells behave as CSCs. Stemness is then probed by comparative transcriptomics of serial PDXs generating a gene signature of epithelial to mesenchymal transition, invasion/motility, metastasis, and self-renewal, pinpointing putative MRT CSC markers. The relevance of these putative CSC molecules is analyzed by sorting tumorigenic fractions from early-passaged PDX according to one such molecule, deciphering expression in archived primary tumors, and testing the effects of CSC molecule inhibition on MRT growth. Using this platform, we identify ALDH1 and lysyl oxidase (LOX) as relevant targets and provide a larger framework for target and drug discovery in rare pediatric cancers.

Combined analysis of morphology and fluorescence in situ hybridization in follow-up of minimal residual disease in a child with Philadelphia-positive acute lymphoblastic leukemia.

The past decade has brought new technologies to the study of minimal residual disease (MRD) in leukemia. Each of them has limitations and is far from being accurate. Recently, a new multiparametric cell scanning system (Duet) was introduced to the field of MRD detection. This system has the advantage of automatically scanning large numbers of cells and performing combined analysis of morphology and fluorescence in situ hybridization (FISH) on the same cell. We used this system to characterize the lineage and degree of maturation of the cells carrying the minor m-BCR/ABL fusion, in a follow-up of an 8-year-old boy with Philadelphia-positive (Ph(+)) acute lymphoblastic leukemia (ALL). The boy was treated using a high-risk protocol and was closely monitored with FISH analysis for cells carrying the m-BCR/ABL fusion. Consecutive analysis along 2.5 years from remission showed 0.2-4.5% m-BCR/ALB(+) cells in the peripheral blood (PB), which is within the accepted background range for this method. The combined analysis found that all the m-BCR/ABL(+) cells were mature lymphocytes. Because mature lymphocytes have a long life span in the circulation, this finding supports the fact that the patient is in remission. Moreover, since mature differentiated cells have a low proliferative capacity, there is a low risk for relapse.