Emerging role of glutathione peroxidase 4 in myeloid cell lineage development and acute myeloid leukemia.

Phospholipid Hydroperoxide Gluthatione Peroxidase also called Glutathione Peroxidase 4 is one of the 25 described human selenoproteins. It plays an essential role in eliminating toxic lipid hydroxy peroxides, thus inhibiting ferroptosis and favoring cell survival. GPX4 is differentially expressed according to myeloid differentiation stage, exhibiting lower expression in hematopoietic stem cells and polymorphonuclear leucocytes, while harboring higher level of expression in common myeloid progenitors and monocytes. In addition, GPX4 is highly expressed in most of acute myeloid leukemia (AML) subtypes compared to normal hematopoietic stem cells. High GPX4 expression is consistently correlated to poor prognosis in patients suffering AML. However, the role of GPX4 in the development of the myeloid lineage and in the initiation and progression of myeloid leukemia remains poorly explored. Given its essential role in the detoxification of lipid hydroperoxides, and its overexpression in most of myeloid malignancies, GPX4 inhibition has emerged as a promising therapeutic strategy to specifically trigger ferroptosis and eradicate myeloid leukemia cells. In this review, we describe the most recent advances concerning the role of GPX4 and, more generally ferroptosis in the myeloid lineage and in the emergence of AML. We also discuss the therapeutic interest and limitations of GPX4 inhibition alone or in combination with other drugs as innovative therapies to treat AML patients.

HSPA8 Chaperone Complex Drives Chaperone-Mediated Autophagy Regulation in Acute Promyelocytic Leukemia Cell Differentiation.

INTRODUCTION: Acute myeloid leukemia (AML) is a cancer of the hematopoietic system characterized by hyperproliferation of undifferentiated cells of the myeloid lineage. While most of AML therapies are focused toward tumor debulking, all-trans retinoic acid (ATRA) induces neutrophil differentiation in the AML subtype acute promyelocytic leukemia (APL). Macroautophagy has been extensively investigated in the context of various cancers and is often dysregulated in AML where it can have context-dependent pro- or anti-leukemogenic effects. On the contrary, the implications of chaperone-mediated autophagy (CMA) on the pathophysiology of diseases are still being explored and its role in AML remains elusive. METHODS: We took advantage of human AML primary samples and databases to analyze CMA gene expression and activity. Furthermore, we used ATRA-sensitive (NB4) and -resistant (NB4-R1) APL cells to further dissect a potential function for CMA in ATRA-mediated neutrophil differentiation. NB4-R1 cells are unique in that they do respond to retinoic acid transcriptionally but do not mature in response to retinoid signaling alone unless maturation is triggered by adding cyclic adenosine monophosphate. RESULTS: Here, we report that CMA-related mRNA transcripts are significantly higher expressed in immature hematopoietic cells as compared to neutrophils, contrasting the macroautophagy gene expression patterns. Accordingly, lysosomal degradation of an mCherry-KFERQ CMA reporter decreases during ATRA-induced differentiation of APL cells. On the other hand, using NB4-R1 cells we found that macroautophagy flux primed ATRA-resistant NB4-R1 cells to differentiate upon ATRA treatment but reduced the association of lysosome-associated membrane protein type 2A (LAMP-2A) and heat shock protein family A (Hsp70) member 8 (HSPA8), necessary for complete neutrophil maturation. Accordingly, depletion of HSPA8 attenuated CMA activity and facilitated APL cell differentiation. In contrast, maintaining high CMA activity by ectopic expression of LAMP-2A impeded APL differentiation. CONCLUSION: Overall, our findings suggest that APL neutrophil differentiation requires CMA inactivation and that this pathway predominantly depends on HSPA8 and is possibly assisted by other co-chaperones.

General practitioners and palliative care practices: a better knowledge of specific services is still needed.

BACKGROUND: France allows deep sedation for pain relief, but not for euthanasia. In anticipation of an increase in home-based palliative care, the role of general practitioners is central to the design of outpatient palliative care services. This study aimed to describe the knowledge, attitudes, and practices of general practitioners in mainland France regarding palliative and end of life care. METHODS: This was a national descriptive cross-sectional study within the Sentinelles network. Self-report questionnaires were distributed to general practitioners between November 2020 and November 2021. A descriptive analysis was carried out. RESULTS: Out of the 123 participating general practitioners, 84% had received academic training in palliative care (n = 104). While a significant majority (69%) expressed comfort in pain management, only a quarter (25%) declared that they were competent at indicating deep and continuous sedation for pain relief. Awareness of outpatient palliative care facilities close to their place of practice such as hospitalization at home was over 97% (n = 117/120). Awareness of hospital facilities, including identified palliative care beds on hospital wards and palliative care units, was lower (75% (n = 59/79) and 86% (n = 86/100), respectively). CONCLUSIONS: Our results suggest that French general practitioners are reasonably aware of palliative care resources available. However, there is room for improvement, particularly in understanding hospital-based facilities. Furthermore, a quarter of the general practitioners expressed discomfort with deep and continuous sedation for pain relief, highlighting the need for increased training in this specific aspect of palliative and end of life care.

Hepatitis E Virus Infection in Pediatric Oncology.

BACKGROUND: In the 2016 ESPGHAN recommendations on how to deal with hepatitis E virus infection in immunocompromised children, patients treated with chemotherapy were not specifically mentioned. OBSERVATIONS: Two teenagers treated with chemotherapy for acute leukemia and medulloblastoma, respectively, were diagnosed with hepatic cytolysis. After numerous investigations hepatitis E was found, limiting the good progress of the chemotherapy treatment. CONCLUSION: In the case of liver cytolysis in immunocompromised children treated with chemotherapy, hepatitis E virus infection has to be promptly diagnosed.

Expert survey on coverage and characteristics of pediatric palliative care in Europe - a focus on home care.

BACKGROUND: For children with life-limiting conditions home care is a key component of pediatric palliative care. However, poor information is available on service coverage and in particular on country-specific pediatric palliative home care characteristics. The aim of the study was therefore to describe the association between pediatric palliative care coverage and national activities and obtain detailed information on the pediatric palliative home care structure in different European countries. METHODS: Online survey with in-country experts from N = 33 European countries. RESULTS: Pediatric palliative home care (65.6%) represented the most pediatric palliative care units (15.6%) and the least common services. National documents constituted the most widespread national pediatric palliative care activity (59.4%) and were associated with available services. Pediatric palliative home care could be mostly accessed as a service free of charge to families (95.2%) from the time of a child's diagnosis (85.7%). In most countries, oncological and non-oncological patients were cared for in pediatric palliative home care. Only a minority of home care teams covered home-ventilated children. Pediatric palliative home care usually comprised medical care (81.0%), care coordination (71.4%), nursing care (75.0%) and social support (57.1%). Most countries had at least two professional groups working in home care teams (81.0%), mostly physicians and nurses. In many countries, pediatric palliative home care was not available in all regions and did not offer a 24 h-outreach service. CONCLUSIONS: Pediatric palliative care provision in Europe is heterogeneous. Further work on country-specific structures is needed.

Modulation of the ATM/autophagy pathway by a G-quadruplex ligand tips the balance between senescence and apoptosis in cancer cells.

G-quadruplex ligands exert their antiproliferative effects through telomere-dependent and telomere-independent mechanisms, but the inter-relationships among autophagy, cell growth arrest and cell death induced by these ligands remain largely unexplored. Here, we demonstrate that the G-quadruplex ligand 20A causes growth arrest of cancer cells in culture and in a HeLa cell xenografted mouse model. This response is associated with the induction of senescence and apoptosis. Transcriptomic analysis of 20A treated cells reveals a significant functional enrichment of biological pathways related to growth arrest, DNA damage response and the lysosomal pathway. 20A elicits global DNA damage but not telomeric damage and activates the ATM and autophagy pathways. Loss of ATM following 20A treatment inhibits both autophagy and senescence and sensitizes cells to death. Moreover, disruption of autophagy by deletion of two essential autophagy genes ATG5 and ATG7 leads to failure of CHK1 activation by 20A and subsequently increased cell death. Our results, therefore, identify the activation of ATM by 20A as a critical player in the balance between senescence and apoptosis and autophagy as one of the key mediators of such regulation. Thus, targeting the ATM/autophagy pathway might be a promising strategy to achieve the maximal anticancer effect of this compound.

Clonal selection in therapy-related myelodysplastic syndromes and acute myeloid leukemia under azacitidine treatment.

INTRODUCTION: Therapy-related myelodysplastic syndrome and acute myeloid leukemia (t-MDS/AML) are defined as complications of previous cytotoxic therapy. Azacitidine (AZA), a hypomethylating agent, has showed activity in t-MDS/AML. OBJECTIVES: We evaluated the clonal dynamics of AZA-treated t-MDS/AML. METHODS: We collected bone marrow samples, at diagnosis and during treatment, from AZA-treated t-MDS/AML patients. NGS on 19 myeloid genes was performed, and candidate mutations with a variant allele frequency >5% were selected. RESULTS: Seven t-AML and 12 t-MDS were included with median age of 71 (56-82) years old, median number of AZA cycles of 6 (1-15), and median overall survival (OS) of 14 (3-29) months. We observed correlation between AZA response and clonal selection. Decrease of TP53-mutated clone was correlated with response to AZA, confirming AZA efficacy in this subgroup. In some patients, emergence of mutations was correlated with progression or relapse without impact on OS. Clones with mutations in genes for DNA methylation regulation frequently occurred with other mutations and remained stable during AZA treatment, independent of AZA response. CONCLUSION: We confirmed that the molecular complexity of t-MNs and that the follow-up of clonal selection during AZA treatment could be useful to define treatment combination.

Acadesine Circumvents Azacitidine Resistance in Myelodysplastic Syndrome and Acute Myeloid Leukemia.

Myelodysplastic syndrome (MDS) defines a group of heterogeneous hematologic malignancies that often progresses to acute myeloid leukemia (AML). The leading treatment for high-risk MDS patients is azacitidine (Aza, Vidaza®), but a significant proportion of patients are refractory and all patients eventually relapse after an undefined time period. Therefore, new therapies for MDS are urgently needed. We present here evidence that acadesine (Aca, Acadra®), a nucleoside analog exerts potent anti-leukemic effects in both Aza-sensitive (OCI-M2S) and resistant (OCI-M2R) MDS/AML cell lines in vitro. Aca also exerts potent anti-leukemic effect on bone marrow cells from MDS/AML patients ex-vivo. The effect of Aca on MDS/AML cell line proliferation does not rely on apoptosis induction. It is also noteworthy that Aca is efficient to kill MDS cells in a co-culture model with human medullary stromal cell lines, that mimics better the interaction occurring in the bone marrow. These initial findings led us to initiate a phase I/II clinical trial using Acadra® in 12 Aza refractory MDS/AML patients. Despite a very good response in one out 4 patients, we stopped this trial because the highest Aca dose (210 mg/kg) caused serious renal side effects in several patients. In conclusion, the side effects of high Aca doses preclude its use in patients with strong comorbidities.

Modular synthesis of new C-aryl-nucleosides and their anti-CML activity.

The C-aryl-ribosyles are of utmost interest for the development of antiviral and anticancer agents. Even if several synthetic pathways have been disclosed for the preparation of these nucleosides, a direct, few steps and modular approaches are still lacking. In line with our previous efforts, we report herein a one step - eco-friendly ß-ribosylation of aryles and heteroaryles through a direct Friedel-Craft ribosylation mediated by bismuth triflate, Bi(OTf)3. The resulting carbohydrates have been functionalized by cross-coupling reactions, leading to a series of new C-aryl-nucleosides (32 compounds). Among them, we observed that 5d exerts promising anti-proliferative effects against two human Chronic Myeloid Leukemia (CML) cell lines, both sensitive (K562-S) or resistant (K562-R) to imatinib, the "gold standard of care" used in this pathology. Moreover, we demonstrated that 5d kills CML cells by a non-conventional mechanism of cell death.

Implication and Regulation of AMPK during Physiological and Pathological Myeloid Differentiation.

AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine kinase consisting of the arrangement of various α ß, and γisoforms that are expressed differently depending on the tissue or the cell lineage. AMPK is one of the major sensors of energy status in mammalian cells and as such plays essential roles in the regulation of cellular homeostasis, metabolism, cell growth, differentiation, apoptosis, and autophagy. AMPK is activated by two upstream kinases, the tumor suppressor liver kinase B1 (LKB1) and the calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) through phosphorylation of the kinase on Thr172, leading to its activation. In addition, AMPK inhibits the mTOR pathway through phosphorylation and activation of tuberous sclerosis protein 2 (TSC2) and causes direct activation of unc-51-like autophagy activating kinase 1 (ULK1) via phosphorylation of Ser555, thus promoting initiation of autophagy. Although it is well established that AMPK can control the differentiation of different cell lineages, including hematopoietic stem cells (HSCs), progenitors, and mature hematopoietic cells, the role of AMPK regarding myeloid cell differentiation is less documented. The differentiation of monocytes into macrophages triggered by colony stimulating factor 1 (CSF-1), a process during which both caspase activation (independently of apoptosis induction) and AMPK-dependent stimulation of autophagy are necessary, is one noticeable example of the involvement of AMPK in the physiological differentiation of myeloid cells. The present review focuses on the role of AMPK in the regulation of the physiological and pathological differentiation of myeloid cells. The mechanisms of autophagy induction by AMPK will also be addressed, as autophagy has been shown to be important for differentiation of hematopoietic cells. In addition, myeloid malignancies (myeloid leukemia or dysplasia) are characterized by profound defects in the establishment of proper differentiation programs. Reinduction of a normal differentiation process in myeloid malignancies has thus emerged as a valuable and promising therapeutic strategy. As AMPK seems to exert a key role in the differentiation of myeloid cells, notably through induction of autophagy, we will also discuss the potential to target this pathway as a pro-differentiating and anti-leukemic strategy in myeloid malignancies.

CD9, a key actor in the dissemination of lymphoblastic leukemia, modulating CXCR4-mediated migration via RAC1 signaling.

CD9, a member of the tetraspanin family, has been implicated in hematopoietic and leukemic stem cell homing. We investigated the role of CD9 in the dissemination of B acute lymphoblastic leukemia (B-ALL) cells, by stably downregulating CD9 in REH and NALM6 cells. CD9 expression was associated with higher levels of REH cell adhesion to fibronectin and C-X-C motif chemokine receptor 4 (CXCR4)-mediated migration. Death occurred later in NOD/SCID mice receiving REH cells depleted of CD9 for transplantation than in mice receiving control cells. After C-X-C motif chemokine ligand 12 (CXCL12) stimulation, CD9 promoted the formation of long cytoplasmic actin-rich protrusions. We demonstrated that CD9 enhanced RAC1 activation, in both REH cells and blasts from patients. Conversely, the overexpression of a competing CD9 C-terminal tail peptide in REH cytoplasm decreased RAC1 activation and cytoplasmic extension formation in response to CXCL12. Finally, the inhibition of RAC1 activation decreased migration in vitro, and the depletion of RAC1 protein from transplanted REH cells increased mouse survival. Furthermore, a testis-conditioned medium induced the migration of REH and NALM6 cells, and this migration was impeded by an anti-CD9 antibody. The level of CD9 expression also influenced the homing of these cells in mouse testes. These findings demonstrate, for the first time, that CD9 plays a key role in the CXCR4-mediated migration and engraftment of B-ALL cells in the bone marrow or testis, through RAC1 activation.

Synthesis and anti-cancer activities of new sulfonamides 4-substituted-triazolyl nucleosides.

Nucleoside analogues are among the most known drugs commonly used in antiviral and anticancer chemotherapies. Among them, those featuring a five-membered ring nucleobase are of utmost interest such as the anti-cancer agent AICAR or the anti-viral drug ribavirin. Despite its low activity in vitro in different cell lines, AICAR is under clinical development for several pathologies, thanks to its original mode of action. Indeed, AICAR induced autophagy cell death and is able, following this mechanism, to circumvent resistance to apoptotic drugs including kinase inhibitors currently on the market. To improve the activity of AICAR, we report herein an efficient synthesis of new series of sulfonamide-4-substituted-1,2,3-triazolyl nucleosides using a Cu-catalyzed 1,3-dipolar cycloaddition. All these molecules have been fully characterized and evaluated against two aggressive tumor cell lines, RCC4 and MDA-MB-231. Among them, nucleoside analogue 5i belonging to the ribose series was found to be 19 to 66-fold more active than AICAR. Western blot analyses on RCC4 cells showed that 5i displayed an interesting mode of action by inducing both apoptosis and autophagy cell death, making therefore this class of molecules highly promising for further hit-to-lead optimization.

Low doses of a neonicotinoid insecticide modify pheromone response thresholds of central but not peripheral olfactory neurons in a pest insect.

Insect pest management relies mainly on neurotoxic insecticides, including neonicotinoids, leaving residues in the environment. There is now evidence that low doses of insecticides can have positive effects on pest insects by enhancing various life traits. Because pest insects often rely on sex pheromones for reproduction, and olfactory synaptic transmission is cholinergic, neonicotinoid residues could modify chemical communication. We recently showed that treatments with different sublethal doses of clothianidin could either enhance or decrease behavioural sex pheromone responses in the male moth, Agrotis ipsilon. We investigated now effects of the behaviourally active clothianidin doses on the sensitivity of the peripheral and central olfactory system. We show with extracellular recordings that both tested clothianidin doses do not influence pheromone responses in olfactory receptor neurons. Similarly, in vivo optical imaging does not reveal any changes in glomerular response intensities to the sex pheromone after clothianidin treatments. The sensitivity of intracellularly recorded antennal lobe output neurons, however, is upregulated by a lethal dose 20 times and downregulated by a dose 10 times lower than the lethal dose 0. This correlates with the changes of behavioural responses after clothianidin treatment and suggests the antennal lobe as neural substrate involved in clothianidin-induced behavioural changes.

Autophagy is required for CSF-1-induced macrophagic differentiation and acquisition of phagocytic functions.

Autophagy is the process by which superfluous or damaged macromolecules or organelles are degraded by the lysosome. Pharmacologic and genetic evidence indicates that autophagy plays pleiotropic functions in cellular homeostasis, development, survival, and differentiation. The differentiation of human blood monocytes into macrophages is a caspase-dependent process when triggered ex vivo by colony stimulating factor-1. We show here, using pharmacologic inhibitors, siRNA approaches, and Atg7-/- mice, that autophagy initiated by ULK1 is required for proper colony stimulating factor-1-driven differentiation of human and murine monocytes. We also unravel a role for autophagy in macrophage acquisition of phagocytic functions. Collectively, these findings highlight an unexpected and essential role of autophagy during monocyte differentiation and acquisition of macrophage functions.

Hearing loss during osteosarcoma chemotherapy: when acute ifosfamide toxicity revealed unnoticed methotrexate encephalopathy.

Ifosfamide and methotrexate are widely used for the treatment of pediatric osteosarcoma. However, both these chemotherapeutic drugs can cause encephalopathy. A 17-year-old girl presented with profound hearing loss and dizziness during a postoperative course of ifosfamide, 20 days after a course of methotrexate. Cerebral magnetic resonance imaging (MRI) showed bilateral white matter hypersignal in Fluid Attenuated Inversion Recovery sequences. The clinical evolution was rapidly favorable after methylene blue infusion. This is the second reported case of acute deafness, possibly associated with ifosfamide, whereas MRI data revealed unnoticed chronic methotrexate toxicity. Systematic MRI screening and hearing evaluation may be useful in such cases.

A novel Nav1.8-FLPo driver mouse for intersectional genetics to uncover the functional significance of primary sensory neuron diversity.

The recent development of single-cell and single-nucleus RNA sequencing has highlighted the extraordinary diversity of dorsal root ganglia neurons. However, the few available genetic tools limit our understanding of the functional significance of this heterogeneity. We generated a new mouse line expressing the flippase recombinase from the scn10a locus. By crossing Nav1.8Ires-FLPo mice with the AdvillinCre and RC::FL-hM3Dq mouse lines in an intersectional genetics approach, we were able to obtain somatodendritic expression of hM3Dq-mCherry selectively in the Nav1.8 lineage. The bath application of clozapine N-oxide triggered strong calcium responses selectively in mCherry+ neurons. The intraplantar injection of CNO caused robust flinching, shaking, and biting responses accompanied by strong cFos activation in the ipsilateral lumbar spinal cord. The Nav1.8Ires-FLPo mouse model will be a valuable tool for extending our understanding of the in vivo functional specialization of neuronal subsets of the Nav1.8 lineage for which inducible Cre lines are available.

Improving nutritional status after allogeneic stem cell transplantation: results of phase 2 ALLONUT clinical trial.

Malnutrition increases the risk of non-relapse mortality after allogeneic stem cell transplantation (aHSCT). Here are the results of the ALLONUT clinical trial designed to improve the nutritional outcome of patients receiving aHSCT. ALLONUT is a prospective open label phase 2 clinical trial assessing the efficacy of a close tailored nutritional support and management with traditional and original solutions to improve patients nutritional status following aHSCT. Nutritional status evaluation was performed before transplantation, on Day 0, 30, 100 and one year after transplantation. The study involved 70 patients treated by aHSCT. 10% of patients were moderately or severely malnutrition at baseline and 26.9 were severely malnutrition at D30. Patients' nutritional status improved thanks to the cooking classes and the personalized outpatient nutrition program. At D100, 23% were still malnutrition, while only 10.8% were severely malnutrition one year after transplantation. The QLQ-C30 show that quality of life (QoL) decreased until D30, and improve to reach the pre-transplant level on D100 before exceeding it on D360. The study confirmed that a close, personalized nutritional program combining traditional and original measures can improve both nutritional status and QoL for patients suffering from moderate or severe malnutrition after aHCST.

Paediatric palliative care: why transfuse?

Should indication for transfusion in paediatric palliative care be based on the child's perspective rather than the biological results? An 8-year-old boy presenting a relapse of a stage IV neuroblastoma received regular blood transfusions. A severe exophtalmia led the doctors to question the transfusion strategy. Over 7.5 months, the child received 56 red blood cell units and 31 platelet units. He was hospitalised 50 times. Indication for blood test and transfusion may be regularly and collegially reassessed. Transfusion needs in a palliative strategy can be as high as in a curative strategy. Practices, benefits but also ethical and public health dimensions should be more studied.

The generation, activation, and polarization of monocyte-derived macrophages in human malignancies.

Macrophages are immune cells that originate from embryogenesis or from the differentiation of monocytes. They can adopt numerous phenotypes depending on their origin, tissue distribution and in response to different stimuli and tissue environment. Thus, in vivo, macrophages are endowed with a continuum of phenotypes that are rarely strictly pro-inflammatory or anti-inflammatory and exhibit a broad expression profile that sweeps over the whole polarization spectrum. Schematically, three main macrophage subpopulations coexist in human tissues: naïve macrophages also called M0, pro-inflammatory macrophages referred as M1 macrophages, and anti-inflammatory macrophages also known as M2 macrophages. Naïve macrophages display phagocytic functions, recognize pathogenic agents, and rapidly undergo polarization towards pro or anti-inflammatory macrophages to acquire their full panel of functions. Pro-inflammatory macrophages are widely involved in inflammatory response, during which they exert anti-microbial and anti-tumoral functions. By contrast, anti-inflammatory macrophages are implicated in the resolution of inflammation, the phagocytosis of cell debris and tissue reparation following injuries. Macrophages also play important deleterious or beneficial roles in the initiation and progression of different pathophysiological settings including solid and hematopoietic cancers. A better understanding of the molecular mechanisms involved in the generation, activation and polarization of macrophages is a prerequisite for the development of new therapeutic strategies to modulate macrophages functions in pathological situations.

Nationwide Study of Continuous Deep Sedation Practices Among Pediatric Palliative Care Teams.

CONTEXT: Palliative sedation practices evolved in France when the Claeys-Leonetti law passed in 2016 authorized patient-requested continuous deep sedation (CDS) until death. Its implementation in the pediatric setting is less frequently encountered and can pose several clinical and ethical challenges for health care teams and families. OBJECTIVES: Our study aimed to describe CDS requests and practices of patients receiving specialized pediatric palliative care in France since its legalization in 2016. METHODS: We conducted a nationwide multicentric, descriptive, retrospective study using a self-report questionnaire completed by all Pediatric Palliative Care (PPC) Teams that were involved in a CDS case between January 2017 and December 2019. RESULTS: Six PPC teams had cared for six patients that had requested CDS, predominantly male adolescents/young adults diagnosed with a solid tumour. The refractory symptoms were diverse (pain, bleeding, and sensory loss) and always coupled with psycho-existential suffering. Each request was analyzed in multidisciplinary collegial meetings. Parental consent was always obtained regardless of age. Sedation typically required the use of multiple drugs including Midazolam (n = 5 cases), Chlorpromazine (n = 3), Ketamine (n = 2), and Propofol (n = 2). Despite close monitoring, achieving a satisfactory level of deep sedation was challenging and most patients unexpectedly awoke during CDS. Death occurred between 27 and 96 hours after induction. CONCLUSION: Managing patient-requested CDS in pediatrics is challenging due to its rarity, multi-factorial refractory symptoms and drug tolerance despite polytherapy. Few recommendations exist to guide CDS practice for pediatricians. Further studies investigating pediatric CDS practices across various cultural and legal settings, refractory symptom management and specific pharmacology are warranted.