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Vaso-occlusive episodes (VOEs) are a common complication of sickle cell disease (SCD) and a significant cause of morbidity. Managing VOE pain can be difficult and complex. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been used to manage VOE pain. This systematic literature review synthesizes research published from 2010 to 2020 on the use of ketamine infusion to decrease VOE pain. The review demonstrates that ketamine, a safe and effective treatment for VOE pain, could be considered more widely. However, the significant variability among published clinical studies with regard to dosing, timing of initiation, duration of infusion, and timing of discontinuation highlights the need for standardized ketamine infusion protocols for the management of VOE pain. We conclude with a brief discussion of key components of a potential standardized protocol supported by the literature reviewed as well as areas for future investigation.

ObjectivesGiven the fundamental role of newborn bloodspot screening (NBS) to enable prompt diagnosis and optimal clinical management of individuals with sickle cell disease (SCD), we sought to systematically assess enablers and barriers to implementation of NBS programmes for SCD in Africa using established qualitative research methods.SettingChildbirth centres and NBS laboratories from six countries in East, West and Southern Africa.ParticipantsEight programme leaders involved with establishing and operating NBS programmes for SCD in Angola, Democratic Republic of Congo, Ghana, Liberia, Nigeria and Tanzania.Primary and secondary outcome measuresData obtained through a structured, phased interview approach were analysed using a combination of inductive and deductive codes and used to determine primary themes related to the implementation and sustainability of SCD NBS programmes.ResultsFour primary themes emerged from the analysis relating to governance (eg, pragmatic considerations when deploying overcommitted clinical staff to perform NBS), technical (eg, design and execution of operational processes), cultural (eg, variability of knowledge and perceptions of community-based staff) and financial (eg, issues that can arise when external funding may effectively preclude government inputs) aspects. Key learnings included perceived factors that contribute to long-term NBS programme sustainability.ConclusionsThe establishment of enduring NBS programmes is a proven approach to improving the health of populations with SCD. Organising such programmes in Africa is feasible, but initial implementation does not assure sustainability. Our analysis suggests that future programmes should prioritise government partner participation and funding from the earliest stages of programme development.

In this chapter, we present a case of back pain in an adolescent with sickle cell disease (SCD). We highlight the pathophysiology of SCD and the differential diagnoses of back pain in patients with SCD. Vaso-occlusive events, back pain as a prodromal symptom to acute chest syndrome (ACS), back pain due to osteomyelitis, and delayed hemolytic transfusion reactions (DHTR) are reviewed. A thorough history is imperative including any recent pain episodes or transfusions. The utility of imaging of the spine in a patient with SCD can be limited since many pain etiologies demonstrate similar findings. Therefore, a high index of suspicion combined with a careful history, physical examination, laboratory evaluation, and imaging is key to the diagnosis and management of back pain in patients with SCD.

Key Points Question Is blood type O associated with a higher prevalence hemorrhage in children after tonsillectomy with or without adenoidectomy? Findings In this cohort study of nearly 15 000 children who underwent tonsillectomy with or without adenoidectomy, the hemorrhage rate following surgery was 3.9%. In the cohort of children for whom a blood type was known, those with blood type O experienced bleeding as frequently as those with non-O types, despite having significantly lower baseline von Willebrand factor values. Meaning The findings of this study indicate that bleeding rates after tonsillectomy with or without adenoidectomy are similar in children with blood type O and those with non-O types., This cohort study examines whether blood type O is associated with hemorrhage after tonsillectomy with or without adenoidectomy in children., Importance Blood type (BT) O has been identified as a risk factor for bleeding complications, while non-O BTs may increase risk for thromboembolic events. Limited data are available in children undergoing tonsillectomy with or without adenoidectomy. Objective To determine whether BT O is associated with hemorrhage after tonsillectomy with or without adenoidectomy. Design, Setting, and Participants Retrospective cohort study of patients younger than 22 years who underwent tonsillectomy with or without adenoidectomy at a single institution between January 1, 2008, and August 7, 2017. Statistical analysis was performed from November 2017 to January 2019. Main Outcomes and Measures Prevalence of hemorrhage following surgery was defined as any bleeding requiring cauterization up to 1 month after the procedure. Data on sex, age, von Willebrand disease (VWD) status, BT, white blood cell counts, and platelet counts closest to date of surgery were collected from an electronic medical record system, and the association of these factors with hemorrhage following surgery was investigated. Results A total of 14 951 pediatric patients (median [range] age, 5.6 [0.8-21.9] years; 6956 [46.5%] female) underwent tonsillectomy with or without adenoidectomy. Prevalence of hemorrhage following the procedure was 3.9% (578 patients) for the full cohort and 2.8% (362 of 13 065) for patients with no BT identified or preprocedure VWD panel results at baseline. Children who had a BT identified and/or a VWD panel before surgery had higher bleeding rates (BT only, 14.9% [172 of 1156]; preprocedure VWD panel only, 4.6% [28 of 607]; and BT and preprocedure VWD panel, 13.0% [16 of 123]), all of which were significantly different from the baseline bleeding rate (P .99), mean von Willebrand factor values were statistically different (mean [SD] von Willebrand factor antigen level in O group, 86.9 [42.4] IU/dL in the O group vs 118.0 [53.8] IU/dL in the non-O group; P = .002; and mean [SD] von Willebrand factor ristocetin-cofactor in the O group, 72.2 [44.3] IU/dL vs 112.6 [68.0] IU/dL in the non-O group; P = .001). In addition, children older than 12 years had increased bleeding rates in the full cohort (8.3% vs 3.2%), in the testing-naive cohort (6.5% vs 2.3%), and in those with a preprocedure VWD panel only (13.5% vs 3.1%) compared with children aged 12 years or younger. Conclusions and Relevance Type O blood was not a risk factor associated with hemorrhage after tonsillectomy with or without adenoidectomy despite lower baseline von Willebrand factor antigen and von Willebrand factor ristocetin-cofactor values in children with BT O vs those with non-O BT in our study cohort. No association was found between VWD status and bleeding, and there was no difference in VWD panel values in those who experienced hemorrhage vs those who did not within BT groups. Further studies elucidating the utility of von Willebrand factor values for children undergoing tonsillectomy with or without adenoidectomy are needed.

Sickle cell trait (AS) confers partial protection against lethal Plasmodium falciparum malaria. Multiple mechanisms for this have been proposed, with a recent focus on aberrant cytoadherence of parasite-infected red blood cells (RBCs). Here we investigate the mechanistic basis of AS protection through detailed temporal mapping. We find that parasites in AS RBCs maintained at low oxygen concentrations stall at a specific stage in the middle of intracellular growth before DNA replication. We demonstrate that polymerization of sickle hemoglobin (HbS) is responsible for this growth arrest of intraerythrocytic P. falciparum parasites, with normal hemoglobin digestion and growth restored in the presence of carbon monoxide, a gaseous antisickling agent. Modeling of growth inhibition and sequestration revealed that HbS polymerization-induced growth inhibition following cytoadherence is the critical driver of the reduced parasite densities observed in malaria infections of individuals with AS. We conclude that the protective effect of AS derives largely from effective sequestration of infected RBCs into the hypoxic microcirculation.

Key Points P falciparum growth is not inhibited in either cord or heterozygote hereditary persistence of fetal hemoglobin erythrocytes. P falciparum growth in fetal hemoglobin erythrocytes is oxygen independent.

Hereditary xerocytosis (HX) is caused by missense mutations in either the mechanosensitive cation channel PIEZO1 or the Ca2+-activated K+channel KCNN4. All HX-associated KCNN4 mutants studied to date have revealed increased current magnitude and red cell dehydration. Baseline KCNN4 activity was increased in HX red cells heterozygous for KCNN4 mutant V282M. However, HX red cells maximally stimulated by Ca2+ionophore A23187 or by PMCA Ca2+-ATPase inhibitor orthovanadate displayed paradoxically reduced KCNN4 activity. This reduced Ca2+-stimulated mutant KCNN4 activity in HX red cells was associated with unchanged sensitivity to KCNN4 inhibitor senicapoc and KCNN4 activator Ca2+, with slightly elevated Ca2+uptake and reduced PMCA activity, and with decreased KCNN4 activation by calpain inhibitor PD150606. The altered intracellular monovalent cation content of HX red cells prompted experimental nystatin manipulation of red cell Na and K contents. Nystatin-mediated reduction of intracellular K+with corresponding increase in intracellular Na+in wild-type cells to mimic conditions of HX greatly suppressed vanadate-stimulated and A23187 -stimulated KCNN4 activity in those wild-type cells. However, conferral of wild-type cation contents on HX red cells failed to restore wild-type-stimulated KCNN4 activity to those HX cells. The phenotype of reduced, maximally stimulated KCNN4 activity was shared by HX erythrocytes expressing heterozygous PIEZO1 mutants R2488Q and V598M, but not by HX erythrocytes expressing heterozygous KCNN4 mutant R352H or PIEZO1 mutant R2456H. Our data suggest that chronic KCNN4-driven red cell dehydration and intracellular cation imbalance can lead to reduced KCNN4 activity in HX and wild-type red cells.

Sickle cell disease is the most common inherited disease in the United States. Through the effects of hemolysis and vaso-occlusion, it has the potential to incite critical illness involving multiple organ systems. Children with sickle cell disease are at risk of multiple types of shock resulting in a need for ICU care. Our youngest patients with sickle cell disease are at highest risk of infection due to lack of splenic function, and this can present with septic shock. Hypovolemic shock can occur secondary to severe acute anemia as seen with splenic sequestration or a delayed transfusion reaction. As one ages, the risk of cardiac dysfunction – diastolic and systolic dysfunction as well as pulmonary hypertension – can result in cardiogenic shock. In addition to shock, patients with sickle cell disease are at risk for respiratory failure from acute chest syndrome as well as acute neurologic deterioration from stroke. For these reasons, critical care physicians must be familiar with the unique management of sickle cell complications in order to provide the best possible care for this vulnerable population.

Newborn screening (NBS) is one of the most important public health initiatives for decreasing mortality in children with sickle cell disease (SCD). This initiative requires a solid infrastructure and national support. In 2010, newborns were screened in St Damien Hospital in Port-au-Prince, but the

Sickle cell trait has repeatedly been identified as a major human malaria resistance factor. Despite this, the exact mechanism of resistance is unclear. These studies demonstrate how the evolutionarily significant sickle hemoglobin affects Plasmodium falciparum infection success and leads to a better understanding of the molecular basis and pathogenesis of malaria infection.

Polymerization of HbS and cell sickling are the prime pathophysiological events in sickle cell disease (SCD). Over the last 30 years, a substantial understanding at the molecular level has been acquired on how a single amino acid change in the structure of the beta chain of hemoglobin leads to the explosive growth of the HbS polymer and the associated changes in red cell morphology. O2 tension and intracellular HbS concentration are the primary molecular drivers of this process, and are obvious targets for developing new therapies. However, polymerization and sickling are driving a complex network of associated cellular changes inside and outside of the erythrocyte, which become essential components of the inflammatory vasculopathy and result in a large range of potential acute and chronic organ damages. In these areas, a multitude of new targets for therapeutic developments have emerged, with several ongoing or planned new therapeutic interventions. This review outlines the key points of SCD pathophysiology as they relate to the development of new therapies, both at the pre-clinical and clinical levels.

The diagnosis of iron deficiency anemia is typically straightforward, especially when classic biochemical and hematological changes are present in a subject at risk. It can be challenging in the presence of diseases or when it is due to inherited defects of iron metabolism. The identification of iron deficiency prior to anemia development is also difficult. New hematological parameters such as reticulocyte Hb content have expanded the classic ones such as MCV, MCH and MCHC. A variety of hematology analyzers now provide novel parameters to assess cellular hypochromia and microcytosis in both reticulocytes and mature red blood cells. The repertoire of biochemical markers has also been expanded, with iron, transferrin and ferritin being supplemented by circulating transferrin receptor and hepcidin. Molecular identification of functional variants of key iron metabolism determinants has provided explanations for the heritability of some iron metabolism biomarkers. Genetic defects in some of these molecules are responsible for hereditary microcytic anemias, also called atypical microcytic anemias. In this review, we examine the most significant hematological and biochemical markers for iron metabolism, as well as relevant genetic polymorphisms and defects affecting iron handling.

Background Rhabdomyosarcoma survivors have an increased risk of developing second malignant neoplasms (SMN); this risk is traditionally attributed to the effects of multidisciplinary management required for cure. However, the impact of constitutional predisposition has not been properly analyzed. Methods We analyzed the risk of SMN among 1,151 children diagnosed with rhabdomyosarcoma and reported to the Surveillance, Epidemiology, and End Results registries (SEER-9) from 1973 to 2010. Standardized incidence ratios (SIR) and corresponding 95% confidence intervals (CI) were calculated using SEERStat 8.1.2. Results Children with pleomorphic and embryonal rhabdomyosarcoma had an increased risk of developing a SMN (SIR = 15.77, 95%CI 1.91–56.96 and SIR = 5.6, 95%CI 3.32–8.85, respectively). The risk was age-dependent; the highest was among children 10 years (SIR = 3.35, 95%CI 1.53–6.35). The risk for the youngest patients was higher for those with embryonal rhabdomyosarcoma (SIR = 14.72, 95%CI 4.01–37.70) compared to other histiotypes. Additionally, the risk of SMN was independent of the use of radiation to the primary (SIR = 6.50, 95%CI 3.97–10.03 and SIR = 4.57, 95%CI 2.09–8.68, for children receiving and not receiving radiation, respectively). The pattern of SMN observed was consistent with the Li-Fraumeni spectrum. Conclusions Children with rhabdomyosarcoma are at high risk of developing SMN. This risk is higher for a subgroup of young children with pleomorphic and embryonal histologies, and is independent of the use of radiation. This suggests that a subgroup of children with pleomorphic and embryonal rhabdomyosarcoma may have a constitutional cancer predisposition. Pediatr Blood Cancer 2015; 9999:1–6 © 2015 Wiley Periodicals, Inc.

A 21 year old male student presented in 1980 as an Olympic athlete with a 12 year history of jaundice, pallor, and darkened urine induced by the atraumatic exercise of swimming (1). Physical examination at that time was remarkable only for moderate scleral icterus without hepatosplenomegaly. Hematological examination revealed moderate macrocytosis (MCV 102 fL) without anemia (Hct 50%, Hb 17 g/dL, 9% reticulocytes). The peripheral blood smear showed occasional target cells. Red cell osmotic fragility was decreased. Red cell Na content was increased and K content was decreased, with reduced total monovalent ion content. Passive red cell permeability of both Na and K were increased. A supervised 2.5 hr swimming workout increased free plasma Hb from

Introduction: We have demonstrated that sickle hemoglobin (HbS) polymerization in low oxygen (O2) is the main driver of sickle cell trait (AS) resistance to P.falciparum malaria. This suggests that homozygous sickle cell disease (SS) individuals should have even greater resistance to malaria. Instead SS individuals infected by P. falciparum often have increased malaria morbidity and mortality compared to individuals with normal hemoglobin (AA) or AS. The reasons for this paradox are poorly understood. We propose that fetal hemoglobin (HbF) inhibits polymerization thereby allowing parasite proliferation. To test this hypothesis the following experiments were performed. Methods: AA and SS erythrocytes were collected within two weeks of the assay date. P. falciparum 3D7 parasites were used for growth assays. Growth assays were performed at 1, 3, 5, 7.5, 10 and 16% O2 using synchronized schizonts obtained by magnet purification via the MACS system. Staging was performed via light microscopy analysis of May-Grünwald-Giemsa-stained cytospins. Parasite Multiplication Rate (PMR) was determined via flow cytometry using parasitemia at 64 and 16 hours post infection (hpi) as previously described. Results: In contrast to AS erythrocytes, SS RBCs contain varying amounts of HbF that differ by cell and by individual. In hypoxic SS RBCs with low (3.8%) HbF, P. falciparum parasites remain immature (early trophozoites) in 1, 3, and 5% O2 (Fig. 1) at 36 hpi, when they should have matured into schizonts. However, in SS RBCs with high (22.6%) HbF, 12, 16 and 27% of parasites matured into schizonts in 1, 3 and 5% O2 respectively compared to 0, 0, and 1% in the SS RBCs with 3.8% HbF. Preliminary data also demonstrate that the parasite multiplication rate (PMR), a surrogate of proliferation, in SS RBCs improves with increasing O2 and HbF. Using SS/Hereditary Persistence of Fetal Hemoglobin RBCs with 42% HbF, proliferation in 5% O2 or higher is exponential with a PMR of 2.6 or greater (Fig. 2). In RBCs isolated from SS patients treated with hydroxyurea with HbF of 26.4 or 21%, PMR is 2 or more in 7.5% O2 or greater. Conclusion: These data demonstrate that HbF promotes P. falciparum growth in SS erythrocytes. In addition, the data initiates a resolution of the malaria paradox. HbS in both hypoxic AS and SS surely inhibits P. falciparum growth due to HbS polymerization at low O2. But high levels of anti-sickling HbF observed in erythrocytes from many individuals with SS reverses this inhibition despite the increased content of HbS in SS individuals. Even small increases in P. falciparum proliferation within the broadly compromised SS host may enhance the malaria associated morbidity and mortality seen in this population. These data further suggest the importance of anti-malarial prophylaxis in patients with SS especially those treated with hydroxyurea or anti-sickling agents. Disclosures No relevant conflicts of interest to declare.

BACKGROUND Rhabdomyosarcoma (RMS) represents a diverse category of myogenic malignancies with marked differences in molecular alterations and histology. This study examines the question if RMS predisposition due to germline TP53 mutations correlates with certain RMS histologies. METHODS The histology of RMS tumors diagnosed in 8 consecutive children with TP53 germline mutations was reviewed retrospectively. In addition, germline TP53 mutation analysis was performed in 7 children with anaplastic RMS (anRMS) and previously unknown TP53 status. RESULTS RMS tumors diagnosed in 11 TP53 germline mutation carriers all exhibited nonalveolar, anaplastic histology as evidenced by the presence of enlarged hyperchromatic nuclei with or without atypical mitotic figures. Anaplastic RMS was the first malignant diagnosis for all TP53 germline mutation carriers in this cohort, and median age at diagnosis was 40 months (mean, 40 months ± 15 months; range, 19-67 months). The overall frequency of TP53 germline mutations was 73% (11 of 15 children) in pediatric patients with anRMS. The frequency of TP53 germline mutations in children with anRMS was 100% (5 of 5 children) for those with a family cancer history consistent with Li-Fraumeni syndrome (LFS), and 80% (4 of 5 children) for those without an LFS cancer phenotype. CONCLUSIONS Individuals harboring germline TP53 mutations are predisposed to develop anRMS at a young age. If future studies in larger anRMS cohorts confirm the findings of this study, the current Chompret criteria for LFS should be extended to include children with anRMS irrespective of family history. Cancer 2014;120:1068–1075. © 2013 American Cancer Society.

Objectives Sialoblastoma is a rare congenital salivary gland tumor of epithelial origin. The objectives of this study are to review the literature regarding clinical presentation of sialoblastoma, evaluate the effectiveness of various treatment methods, and present guidelines for evaluation and management in the pediatric population. Data sources: Case presentation and literature review. Review methods A comprehensive search was conducted to identify cases of pediatric sialoblastoma in the English-language literature. The presentation, evaluation, and management of reported cases were analyzed. We also report an invasive and recurrent case in a pediatric patient to highlight the aggressive nature of these lesions. Results Sixty-two cases of pediatric sialoblastoma were reviewed. The age at initial presentation ranged from before birth to 15 years. The parotid gland was the most common location (n = 47). Surgical excision was the primary treatment in all patients. Nine patients developed metastatic disease of the lung, lymph nodes, or bone. Almost a third of patients had recurrence and over two thirds of patients were tumor-free for at least 1 year following their last treatment intervention. Conclusion Prompt and complete surgical excision should be recommended to prevent local and systemic recurrence of pediatric sialoblastoma. Chemotherapy has also shown promise in several cases, and clinical genomics may shed light on more therapy options. Patients should be closely followed for at least 12 months following diagnosis, or longer depending on the histopathological staging of the tumor.

Introduction: The risk of clinical Plasmodium falciparum malaria is significantly low in the first few months of life. Much of this protection has been attributed to maternal antibodies transmitted to the infant in utero or via breast milk, however less severe disease has also been associated with fetal hemoglobin (HbF). Impaired P. falciparum growth in cord blood erythrocytes and reduced digestion of HbF protein by recombinant plasmepsin II, a hemoglobinase, has also been observed in vitro, while in vivo studies have demonstrated decreased P. falciparum growth in high HbF-containing human gamma (γ)-transgenic murine red cells. Though inefficiency of hemoglobinase digestion of HbF appears plausible given enhanced alpha (α)/γ relative to α/beta (β) dimer and tetramer stability, it has been difficult to assess such inefficiency in vitro given the dramatic effect of current protease inhibitors on parasite growth. Instead, more focus has drifted towards oxidative stress and poor cytoadherence as mechanisms underlying the protection conferred by HbF. To test the hypothesis that HbF affects malaria infection, we mapped P. falciparum growth in cord blood and heterozygote A/HPFH erythrocytes using precise DNA replication measurements throughout the parasite blood stage cell-cycle. Methods: Adult (AA), cord, and heterozygote Hereditary Persistence of Fetal Hemoglobin (A/HPFH) samples were collected within one week of each other and within 1 month of assay date. The P. falciparum 3D7 IG06 parasite line (a gift from Daniel Goldberg, Washington University School of Medicine, St. Louis) was used for growth assays. All growth assays were performed at 1% oxygen using synchronized schizonts obtained by magnet purification via the MACS system. Average number of nuclei per parasite was determined via flow cytometry using SYBR Mean Fluorescence Intensity (MFI) as previously described. Results: By 32 hours post invasion into cord blood, a definite decrease in P. falciparum DNA replication, a sensitive marker of parasite growth, was observed compared to growth in adult erythrocytes (Figure 1A). Compared to the complete growth defect observed in deoxygenated sickle cell trait (AS), the almost 40% reduction (p=0.0002) in the average number of nuclei in cord blood RBCs was modest, allowing for growth through schizogony. The growth inhibition in cord blood erythrocytes was not sensitive to changes in oxygen levels (data not shown). Ring/early trophozoite stage parasites were morphologically similar in both adult and cord blood erythrocytes (Figure 1B), with growth differences beginning to be apparent between 28 and 32 hours, coincident with the onset of hemoglobin digestion. To ensure that the growth defect observed was not due to cord blood erythrocyte factors unrelated to HbF, we examined heterozygous A/HPFH RBCs which are similar to adult AA erythrocytes, but with expression of HbF. Parasites in A/HPFH erythrocytes (with ~20-30% HbF), demonstrated a 25% growth reduction in the average number of nuclei at 36hpi, compared to those in adult AA RBCs (Figure 2A and 2B), indicating the growth inhibitory effect of HbF. Conclusion: Though less striking compared to the severe stalling observed in deoxygenated AS RBCs, growth of P. falciparum 3D7 IG06 in cord blood erythrocytes is clearly delayed compared to growth in adult AA erythrocytes. This growth defect is oxygen independent, evidence that a different mechanism of parasite growth inhibition is involved than that observed in AS RBCs. The consistent growth delay observed in heterozygote A/HPFH confirms that parasite growth deficiency also occurs at lower percentages of HbF than those found in cord blood presumably because α2/γ-β heterodimers are also resistant to digestion by P. falciparum hemoglobinases. Finally, these data suggest that treatment of sickle cell disease by increasing fetal hemoglobin might be safer in malaria zones than would be employment of direct anti-sickling agents. Disclosures Hankins: Global Blood Therapeutics: Research Funding; NCQA: Consultancy; bluebird bio: Consultancy; Novartis: Research Funding.

Human induced pluripotent stem cells (hiPSCs) hold remarkable capacity for disease modeling and the development of novel therapeutic treatments for sickle cell disease (SCD). hiPSCs can theoretically produce all cell types including induced red blood cells (iRBCs). Sickle cell patients, in particular, could benefit from autologous, engineered red blood cells (RBCs). Many patients possess rare Rh phenotypes, are allo-sensitized to blood products and are at risk of iron overload from recurrent transfusions. Therefore, the generation of personalized iRBCs is attractive. Yet, in vitro iRBC production has been hampered by an inability of these cells to differentiate into terminally-mature, enucleated, beta globin-expressing RBCs. Here, we describe updated strategies to improve in vitro production of iRBCs. hiPSCs from sickle cell patients as well as those with normal hemoglobin were differentiated into hematopoietic stem progenitor cells (HSPCs) and immortalized via the overexpression of a previously characterized set of transcription factors promoting self-renewal and multipotency under the control of a doxycycline-regulated promoter. Utilizing an in vitro protocol incorporating increasing concentrations of human plasma, HSPCs differentiated from these lines proceed through terminal erythroid differentiation, including the formation of CD71-/GlyA+/α4 integrin-/Band 3+ cells. Plasma-stimulated iRBCs achieved robust enucleation (11-60.7%) and underwent fetal to adult globin-switching. Further, nearly 21% of the enucleated iRBCs were RNA negative erythrocytes 5-8 microns in diameter. RNA sequencing analysis reveals similar transcriptional profiles between iRBCs and peripheral blood CD34+- derived cultured RBCs (cRBCs) yet distinct differences between SCD and WT iRBCs. SCA iRBCs have increased extracellular matrix organization, cell-cell adhesive properties and up-regulation of hypoxia-response genes. Heme metabolism, DNA repair, fatty acid metabolism and oxidative phosphorylation are all impaired in SCD iRBCs. Assessment of cell physiology exposes membrane damage in SCD iRBCs with increased phalloidin permeability in comparison to wild type controls. Intriguingly, SCD iRBCs co-expressing gamma and beta-globin also demonstrate sickling under hypoxic conditions. With the development of expandable source of erythroid progenitors capable of producing mature red cells, we now aim to utilize this platform for robust disease modeling and autologous cell therapy. Figure. Figure. Disclosures Heeney: Pfizer: Research Funding; Sancilio Pharmaceuticals: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; Ironwood: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees; Vertex/Crisper: Other: Data Monitoring Committee.

Background: Despite the global acceptance of Haldane's hypothesis that individuals with sickle cell trait (AS) are protected against malaria, an exact mechanism of resistance remains unknown. Several theories to explain the resistance such as increased splenic destruction, impaired hemoglobin digestion, reduced cytoadherence and specific translocation of host specific microRNAs have been proposed. Here we carefully examine the influence of hypoxia and its relation to parasite cytoadherence and growth in AS and normal (AA) human red blood cells (RBCs). Materials and Methods: To assess the influence of oxygen tension on parasite proliferation in AS RBCs, we followed the proliferation of tightly synchronized P. falciparum within AS and AA RBCs at 1, 5, 10, and 17% oxygen by flow cytometry and microscopy. Carbon monoxide (CO) studies were performed by introducing 100% CO gas into our enclosed chamber system every 21 hours to prevent sickling at low oxygen. Results: Flow cytometry assessment of DNA content confirms the absence of DNA replication within parasites in AS erythrocytes at low oxygen, however normal DNA replication is observed in the presence of high oxygen tension and when CO is introduced at low oxygen. Moving parasites from high to low oxygen tension greatly influences the extent of parasite maturity; parasites moved at 16 and 20 hours post invasion (hpi) do not mature beyond that of the late ring/early trophozoite stage while parasites moved at 24, 28, and 32 hpi develop increasingly more merozoites. Conclusion: Here, we show that in hypoxic conditions parasites in AS erythrocytes stall at the late ring/early trophozoite stage and do not replicate their DNA. We also show that treatment of AS erythrocytes with high oxygen tension or carbon monoxide, a potent inhibitor of sickle hemoglobin polymerization, reverses this phenotype. We propose that the mechanism of AS protection is largely due to P.falciparum's inability to digest polymerized sickle hemoglobin once the parasite sequesters in the hypoxic microvasculature. This is likely a key driver of the reduced parasite densities observed in actual infections in AS individuals. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Rhabdomyosarcoma survivors have an increased risk of developing second malignant neoplasms (SMN); this risk is traditionally attributed to the effects of multidisciplinary management required for cure. However, the impact of constitutional predisposition has not been properly analyzed.We analyzed the risk of SMN among 1,151 children diagnosed with rhabdomyosarcoma and reported to the Surveillance, Epidemiology, and End Results registries (SEER-9) from 1973 to 2010. Standardized incidence ratios (SIR) and corresponding 95% confidence intervals (CI) were calculated using SEERStat 8.1.2.Children with pleomorphic and embryonal rhabdomyosarcoma had an increased risk of developing a SMN (SIR = 15.77, 95%CI 1.91-56.96 and SIR = 5.6, 95%CI 3.32-8.85, respectively). The risk was age-dependent; the highest was among children2 years (SIR = 13.38, 95%CI 4.34-31.22) and the lowest was in children10 years (SIR = 3.35, 95%CI 1.53-6.35). The risk for the youngest patients was higher for those with embryonal rhabdomyosarcoma (SIR = 14.72, 95%CI 4.01-37.70) compared to other histiotypes. Additionally, the risk of SMN was independent of the use of radiation to the primary (SIR = 6.50, 95%CI 3.97-10.03 and SIR = 4.57, 95%CI 2.09-8.68, for children receiving and not receiving radiation, respectively). The pattern of SMN observed was consistent with the Li-Fraumeni spectrum.Children with rhabdomyosarcoma are at high risk of developing SMN. This risk is higher for a subgroup of young children with pleomorphic and embryonal histologies, and is independent of the use of radiation. This suggests that a subgroup of children with pleomorphic and embryonal rhabdomyosarcoma may have a constitutional cancer predisposition.

Neonatal screening for sickle cell disease (SCD), when linked to early diagnostic testing, parental education, and comprehensive care, markedly reduces morbidity and mortality from the disease in infancy and early childhood (1, 2). Largely unaddressed, the inability to diagnose SCD rapidly, reliably, and at low cost continues to be a significant contributor to high morbidity and mortality in many resource-limited settings. Until recently, few practical and reliable point-of-care methods for the diagnosis of SCD existed. The recent call by major organizations, such as the National Heart, Lung, and Blood Institute and the World Health Organization for simple, rapid and low-cost diagnostic techniques for SCD, has led to more research dedicated to solving this global problem. In 2013, Milligan et al. proposed the use of hemolysis in deoxygenated isosmotic sucrose solution as a method to diagnose SCD (3). In that same year, Yang et al. described a paper-based solubility test able to differentiate between SCD, sickle cell trait, and nonhemoglobin S-containing blood (4). In PNAS, Kumar et al. present an innovative approach to SCD point-of-care testing using density gradients created by aqueous multiphase systems (AMPS) (5).

Hematologic malignancies, a diverse population of malignant diseases further subdivided into leukemia and lymphoma, account for nearly 45% of childhood cancers. Both leukemia and lymphoma can present with head and neck lesions. Acute lymphoblastic leukemia and acute myeloid leukemia can present with either lymphadenopathy or granulocytic sarcoma, a mass of immature cells more common in acute myeloid leukemia where it can occur in up to 10% of patients. Hodgkin lymphoma and Non-Hodgkin lymphoma frequently present with cervical lymphadenopathy. Excisional biopsy of an affected lymph node coupled with bone marrow aspirate and biopsy allow for accurate diagnosis. Once a diagnosis has been made, treatment typically consists of chemotherapy and in some cases includes radiation therapy. Details of treatment decisions may be based on the type of disease, sites of involvement, rist group or stage, as well as factors such as chromosomal abnormalities with known prognostic significance and response to therapy. Most children diagnosed with pediatric leukemia or lymphoma are expected to be long-term, event free survivors.

Rhabdomyosarcoma (RMS) represents a diverse category of myogenic malignancies with marked differences in molecular alterations and histology. This study examines the question if RMS predisposition due to germline TP53 mutations correlates with certain RMS histologies.The histology of RMS tumors diagnosed in 8 consecutive children with TP53 germline mutations was reviewed retrospectively. In addition, germline TP53 mutation analysis was performed in 7 children with anaplastic RMS (anRMS) and previously unknown TP53 status.RMS tumors diagnosed in 11 TP53 germline mutation carriers all exhibited nonalveolar, anaplastic histology as evidenced by the presence of enlarged hyperchromatic nuclei with or without atypical mitotic figures. Anaplastic RMS was the first malignant diagnosis for all TP53 germline mutation carriers in this cohort, and median age at diagnosis was 40 months (mean, 40 months ± 15 months; range, 19-67 months). The overall frequency of TP53 germline mutations was 73% (11 of 15 children) in pediatric patients with anRMS. The frequency of TP53 germline mutations in children with anRMS was 100% (5 of 5 children) for those with a family cancer history consistent with Li-Fraumeni syndrome (LFS), and 80% (4 of 5 children) for those without an LFS cancer phenotype.Individuals harboring germline TP53 mutations are predisposed to develop anRMS at a young age. If future studies in larger anRMS cohorts confirm the findings of this study, the current Chompret criteria for LFS should be extended to include children with anRMS irrespective of family history.

On January 12, 2010, Haiti experienced one of the worst disasters in human history, a magnitude 7.0 earthquake, resulting in the deaths of approximately 222,000 Haitians and grievous injury to hundreds of thousands more. International agencies, academic institutions, nongovernmental organizations, and associations responded by sending thousands of medical professionals, including nurses, doctors, medics, and physical therapists, to support the underresourced Haitian health system. The volunteers who came to provide medical care to disaster victims worked tirelessly under extremely challenging conditions, but in many cases they had no previous work experience in resource-limited settings, minimal training in tropical disease, and no knowledge of the historical background that contributed to the catastrophe. Often, this lack of preparedness hindered their ability to care adequately for their patients. The authors of this perspective argue that the academic medicine community must prepare medical trainees not only to treat the illnesses of patients in resource-limited settings but also to fight the injustice that fosters disease and allows such catastrophes to unfold. The authors advocate purposeful attention to building global health curricula; providing adequate time, funding, and opportunity to work in resource-limited international settings; and ensuring sufficient supervision for trainees to work safely. They also call for an interdisciplinary approach to global health that both affirms health care as a fundamental human right and explores the historical, economic, and political causes of inequitable health care.

222 Background: Given the risk of serious bacterial infection in immunocompromised cancer patients, fever should be promptly treated with empiric antibiotics. Our institutional standard is to administer antibiotics in ≤ 60 minutes from on-site fever or from arrival time with known fever. Review of our febrile outpatient pediatric oncology clinic patients from October-December 2013 revealed that 53% met this metric. Our aim: To achieve a sustained rate of 80% of febrile patients receiving antibiotics in ≤ 60 minutes within 8 weeks. Methods: We developed and implemented a fever fast track tool in our pediatric oncology clinic. Providers time stamped each step in the process from fever to antibiotic administration; additional time points were collected from the medical record. Interviews with staff were conducted to identify barriers. Five revisions of the fever fast track tool were made. We also streamlined same-day encounters for febrile patients in order to flag their acute visits and facilitate pre-arrival order entry. Results: 21 patients were treated for fever between 2/26/14 and 4/17/14. 4 fevers were documented in clinic. Time to antibiotics ranged from 23 minutes to 165 minutes. The median time to antibiotic administration was reduced from 58 minutes during the first four weeks to 40 minutes after the second 4-week block. Over the same period, patients receiving antibiotics in ≤ 60 minutes increased from 62% to 88%. Conclusions: Use of a fever fast track tool improved the proportion of febrile patients receiving antibiotics in ≤ 60 minutes. Modifications facilitating antibiotic order entry and pre-arrival awareness of febrile patients should prove helpful in sustaining this success.

10042 Background: Germline TP53 mutations have been recently described in children with anaplastic EMRS, suggesting a possible association with Li-Fraumeni syndrome (LFS). In this population-based ...

Hemoglobinopathies, including sickle cell disease (SCD) and thalassemia syndromes, represent the commonest monogenic diseases in the world. Although their pathogenicity is well established, the diverse clinical manifestations and the varying degree of severity are less understood and are thought to be governed, in part, by genetic modifiers. Despite the identification and characterization of a few genetic modifiers by previous studies, these are as yet insufficient to guide treatment recommendations or stratify patients reliably. Larger, multi-ethnic studies are needed to identify and validate further disease modifiers that can be used for patient stratification and personalized treatment. There is a growing need for deeper insight with the availability of novel targeted therapies and potentially curative options like gene therapy in both SCD and thalassemia. The International Hemoglobinopathy Research Network (INHERENT) is a recently established network with the aim of investigating the role of genetic modifiers in hemoglobinopathies, through a large-scale, multi-ethnic genome-wide association study (GWAS). INHERENT brings together nine existing international or regional consortia in the field of hemoglobinopathies, namely ITHANET, RADeep, ARISE, SPARCO, SADaCC, REDAC, the HVP Global Globin Network, the International Health Repository, and the ClinGen Hemoglobinopathy VCEP. The activities of INHERENT are currently divided into five working groups, as follows: clinical, genotyping, data management and analysis, ethics, and knowledge translation. Participation in INHERENT is open for any group that can submit a minimum number of samples with their core phenotypic description. INHERENT membership is international and interdisciplinary and, currently, includes over 160 experts from 89 organizations, spanning 36 countries worldwide (Figure). INHERENT aims to recruit over 30,000 hemoglobinopathy patients, which is over one order of magnitude larger than any previous GWAS in the field. We demonstrate that the current membership of INHERENT has the potential to reach this sample size target. The large increase in the sample size and the diversity in the studied populations will enable novel discoveries and expand knowledge on hemoglobinopathy genetics, thus paving the way for advancing the science of personalized diagnosis and treatment. Figure 1 Figure 1. Disclosures Archer: Haemonetics: Current equity holder in publicly-traded company. Kuo: Bluebird Bio: Consultancy; Celgene: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Research Funding; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees. Maggio: Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corp: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees. Mañú Pereira: Novartis: Research Funding; Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding.