Search

Pediatric acute myeloid leukemia (pedAML) is a heterogeneous blood cancer that affects children. Although survival rates have significantly improved over the past few decades, 20-30% of children will succumb due to treatment-related toxicity or relapse. The molecular characterization of the leukemic stem cell, shown to be responsible for relapse, is needed to improve treatment options and survival. Recently, it has become clear that non-coding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), play a role in the development of human diseases, including pediatric cancer. Nevertheless, non-coding RNA expression data in pedAML are scarce. Here, we explored lncRNA (n = 30,168) and miRNA (n = 627) expression in pedAML subpopulations (leukemic stem cells (LSCs) and leukemic blasts (L-blasts)) and their normal counterparts (hematopoietic stem cells and control myeloblasts). The potential regulatory activity of differentially expressed lncRNAs in LSCs (unique or shared with the L-blast comparison) on miRNAs was assessed. Moreover, pre-ranked gene set enrichment analyses of (anti-) correlated protein-coding genes were performed to predict the functional relevance of the differentially upregulated lncRNAs in LSCs (unique or shared with the L-blast comparison). In conclusion, this study provides a catalog of non-coding RNAs with a potential role in the pathogenesis of pedAML, paving the way for further translational research studies. ispartof: CANCERS vol:14 issue:9 ispartof: location:Switzerland status: published

Introduction. — The recently identified role of a BRAF somatic mutation in the pathophysiologyof Langerhans cell histiocytosis (LCH) offers new therapeutic options. Herein we describe thecase of a 10-month-old infant with refractory high-risk LCH successfully treated with vemu-rafenib.Observation. — The patient first presented with cutaneous LCH at the age of 2 months. Thedisease remained undiagnosed until she was 6 months old, when it rapidly evolved to a multisys-temic high-risk and life-threatening disease, refractory to 2 lines of chemotherapy. BRAFV600Emutation was found at skin biopsy, and targeted therapy with vemurafenib was started whenshe was 10 months old. The treatment induced a fast and sustained response, but rapid relapseoccurred after treatment discontinuation, leading to resumption of treatment, once moreresulting in a sustained response.Conclusion. — Our case highlights the first-line role of dermatologists in establishing the diag-nosis of LCH, especially in children, in whom the eruption may be difficult to identify, leading todelayed diagnosis. Targeted therapy with vemurafenib has recently been described in children in this indication and our results support its efficacy, highlighting the need for prolonged treat-ment and raising the question of maintenance therapy, as well as the necessity for large-scaleand long-term studies., info:eu-repo/semantics/published

Background Still 30–40% of pediatric acute myeloid leukemia (pedAML) patients relapse. Delineation of the transcriptomic profile of leukemic subpopulations could aid in a better understanding of molecular biology and provide novel biomarkers. Methods Using microarray profiling and quantitative PCR validation, transcript expression was measured in leukemic stem cells (LSC, n = 24) and leukemic blasts (L-blast, n = 25) from pedAML patients in comparison to hematopoietic stem cells (HSCs, n = 19) and control myeloblasts (C-blast, n = 20) sorted from healthy subjects. Gene set enrichment analysis was performed to identify relevant gene set enrichment signatures, and functional protein associations were identified by STRING analysis. Results Highly significantly overexpressed genes in LSC and L-blast were identified with a vast majority not studied in AML. CDKN1A, CFP, and CFD (LSC) and HOMER3, CTSA, and GADD45B (L-blast) represent potentially interesting biomarkers and therapeutic targets. Eleven LSC downregulated targets were identified that potentially qualify as tumor suppressor genes, with MYCT1, PBX1, and PTPRD of highest interest. Inflammatory and immune dysregulation appeared to be perturbed biological networks in LSC, whereas dysregulated metabolic profiles were observed in L-blast. Conclusion Our study illustrates the power of taking into account cell population heterogeneity and reveals novel targets eligible for functional evaluation and therapy in pedAML. Impact Novel transcriptional targets were discovered showing a significant differential expression in LSCs and blasts from pedAML patients compared to their normal counterparts from healthy controls. Deregulated pathways, including immune and metabolic dysregulation, were addressed for the first time in children, offering a deeper understanding of the molecular pathogenesis. These novel targets have the potential of acting as biomarkers for risk stratification, follow-up, and targeted therapy. Multiple LSC-downregulated targets endow tumor suppressor roles in other cancer entities, and further investigation whether hypomethylating therapy could result into LSC eradication in pedAML is warranted.

SARS-CoV-2 causes a hypercoagulable state that predisposes patients to thromboembolic events. We report two adolescents with Sickle Cell Disease (SCD) who developed pulmonary embolism (PE) during acute chest syndrome (ACS) episode associated with a possible SARS-CoV-2 infection. Both SCD and SARS-CoV-2 infection predisposes to thromboembolic disease. Thromboprophylaxis with LMWH should be considered in adolescent with ACS, related or not to COVID-19 disease.

Immunotherapeutic strategies targeting the rare leukemic stem cell compartment might provide salvage to the high relapse rates currently observed in acute myeloid leukemia (AML). We applied gene expression profiling for comparison of leukemic blasts and leukemic stem cells with their normal counterparts. Here, we show that the T-cell receptor γ chain alternate reading frame protein (TARP) is over-expressed in de novo pediatric (n=13) and adult (n=17) AML sorted leukemic stem cells and blasts compared to hematopoietic stem cells and normal myeloblasts (15 healthy controls). Moreover, TARP expression was significantly associated with a fms-like tyrosine kinase receptor-3 internal tandem duplication in pediatric AML. TARP overexpression was confirmed in AML cell lines (n=9), and was found to be absent in B-cell acute lymphocytic leukemia (n=5) and chronic myeloid leukemia (n=1). Sequencing revealed that both a classical TARP transcript, as described in breast and prostate adenocarcinoma, and an AML-specific alternative TARP transcript, were present. Protein expression levels mostly matched transcript levels. TARP was shown to reside in the cytoplasmic compartment and showed sporadic endoplasmic reticulum co-localization. TARP-T-cell receptor engineered cytotoxic T-cells in vitro killed AML cell lines and patient leukemic cells co-expressing TARP and HLA-A*0201. In conclusion, TARP qualifies as a relevant target for immunotherapeutic T-cell therapy in AML. ispartof: HAEMATOLOGICA vol:105 issue:5 pages:1306-1316 ispartof: location:Italy status: published

BACKGROUND Chronic transfusion in sickle cell disease (SCD) remains the gold standard therapy for stroke prevention and for patients with severe disease despite adequate hydroxyurea treatment. The aim of our study was to assess the safety and efficacy of automated red blood cell exchange (aRBX) in patients with SCD previously treated with manual exchange transfusion (MET). Costs related to transfusion and chelation overtime were evaluated. STUDY DESIGN AND METHODS Beginning in January 2012, children with SCD who weighed 30 kg or more on MET could switch to aRBX. Clinical, biological, and procedures' data, including costs, were recorded for the last 6 months on MET and compared to those after the first and the second year on aRBX. RESULTS Ten patients switched from MET to aRBX at a median age of 11.8 years. After the switch, median hemoglobin S (HbS) increased significantly (33.5% on MET compared to 45% on aRBX; p

PV, NR and MMP contributed equally Introduction Patients with red blood cell disorders (RBCD), chronic life threating multisystemic disorders in their severe forms, are likely to be at increased risk of complications from SARS-Cov-2 (Covid-19), but evidence in this population is scarce due to its low frequency and heterogeneous distribution. ERN-EuroBloodNet, the European Reference Network in rare hematological disorders, established a European registry to determine the impact of COVID-19 on RBCD patients and identify risk factors predicting severe outcomes. Methods The ERN-EuroBloodNet registry was established in March 2020 by Vall d'Hebron Research Institute based on REDcap software in accordance with the Regulation (EU) 2016/679 on personal data. The local Research Ethics Committee confirmed that the exceptional case of the pandemic justifies the waiver of informed consent. The ERN-EuroBloodNet registry on RBCD and COVID-19 is endorsed by the European Hematology Association (EHA). Eligible patients had confirmed RBCD and COVID-19. Data collected included demographics, diagnosis, comorbidities, treatments, and COVID-19 (severity grade, clinical manifestations, acute events, treatments, hospitalization, intensive care unit, death). For analysis of COVID-19 severity, two groups were established 1) Mild: asymptomatic or mild symptoms without clinical pneumonia and 2) Severe: pneumonia requiring oxygen/respiratory support and/or admission to intensive care unit. Continuous variables were compared using the Wilcoxon rank-sum test or Kruskall Wallis test, while categorical variables were analyzed using the Chi-square test or Fisher's Exact test. Relevant factors influencing disease or severity were examined by the logistic regression adjusted for age. Results As of June 2021, 42 medical centers from 10 EU countries had registered 373 patients: 191 Sickle cell disease (SCD), 156 Thalassemia major and intermedia (THAL) and 26 other RBCD. 84% of the SCD patients were reported by Spain, Belgium, Italy and The Netherlands and 92% of the THAL patients by Italy and Greece. The mean age of SCD was lower (22.5y) than of THAL (39.6y) with pediatric population accounting for 50.5% in SCD and 9% in THAL (p Age and BMI correlated with COVID-19 severity, as described in the general population (p=0.002, p Potential risk factors such as elevated ferritin, current chelation or history of splenectomy did not confer additional risk for developing severe COVID-19 in any patient group. Only diabetes as a comorbidity correlated with severity grade in SCD (p=0.011) and hypertension in THAL (p=0.014). While severe COVID-19 infection in SCD was associated with both ACS (p Overall, 14.8% RBC patients needed oxygen/respiratory support, 4.4% were admitted to ICU with an overall mortality rate of 0.8% (no deaths were registered in pediatric age), much lower than reported in other similar cohorts. Discussion Results obtained so far show that severe COVID-19 occurs at younger ages in more aggressive forms of SCD and THAL. Current preventive approaches (shielding, vaccinations) focus on age over disease severity. Our data highlights the risk of severe COVID-19 infection in some young patients, particularly those with SS/SB0 SCD, suggesting that immunization should be considered in this pediatric group as well. Results between similar sized cohorts of RBCD patients vary between each other and those presented here, highlighting the importance of collecting all of these small cohorts together to ensure adequate statistical power so that definitive risk factors (eg. age, genotype, comorbidities) can be reliably identified and used to guide management of patients with these rare disorders in the light of the ongoing pandemic. Figure 1 Figure 1. Disclosures Longo: Bristol Myers Squibb: Honoraria; BlueBird Bio: Honoraria. Bardón-Cancho: Novartis Oncology Spain: Research Funding. Flevari: PROTAGONIST COMPANY: Research Funding; ADDMEDICA: Consultancy, Research Funding; BMS: Research Funding; IMARA COMPANY: Research Funding; NOVARTIS COMPANY: Research Funding. Voskaridou: BMS: Consultancy, Research Funding; IMARA: Research Funding; NOVARTIS: Research Funding; ADDMEDICA: Consultancy, Research Funding; GENESIS: Consultancy, Research Funding; PROTAGONIST: Research Funding. Biemond: GBT: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau; Novo Nordisk: Honoraria; Celgene: Honoraria; Sanquin: Research Funding. Nur: Celgene: Speakers Bureau; Roche: Speakers Bureau; Novartis: Research Funding, Speakers Bureau. Beneitez-Pastor: Agios: Honoraria; Alexion: Honoraria; Novartis: Honoraria; Forma Therapeutics: Honoraria. Pepe: Chiesi Farmaceutici S.p.A: Other: no profit support; Bayer S.p.A.: Other: no profit support. de Montalembert: Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Addmedica: Membership on an entity's Board of Directors or advisory committees; BlueBirdBio: Membership on an entity's Board of Directors or advisory committees; Vertex: Membership on an entity's Board of Directors or advisory committees. Glenthøj: Agios: Consultancy; Novo Nordisk: Honoraria; Novartis: Consultancy; Alexion: Research Funding; Bluebird Bio: Consultancy; Bristol Myers Squibb: Consultancy; Saniona: Research Funding; Sanofi: Research Funding. Benghiat: Novartis: Consultancy; BMS: Consultancy. Labarque: Novartis: Consultancy; Bayer: Consultancy; Sobi: Consultancy; NovoNordisk: Consultancy; Octapharma: Consultancy. Diamantidis: Genesis Pharma: Honoraria; Uni-Pharma: Honoraria; Bristol Myers Squibb: Consultancy; IONIS Pharmaceuticals: Research Funding; NOVARTIS, Genesis Pharma SA: Research Funding. Kerkhoffs: Sanofi: Research Funding; Terumo BCT: Research Funding. Iolascon: Celgene: Other: Advisory Board; Bluebird Bio: Other: Advisory Board. Taher: Vifor Pharma: Consultancy, Research Funding; Agios Pharmaceuticals: Consultancy; Ionis Pharmaceuticals: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy, Research Funding. Colombatti: Novartis: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novonordisk: Membership on an entity's Board of Directors or advisory committees; Forma Therapeutics: Membership on an entity's Board of Directors or advisory committees; Addmedica: Membership on an entity's Board of Directors or advisory committees; BlueBirdBio: Research Funding. Mañú Pereira: Novartis: Research Funding; Agios Pharmaceuticals: Research Funding.

The Belgian sickle cell disease registry (BCR) was initiated in 2008 and aims to evaluate mortality, morbidity as well as clinicals practices in participating centers. The current analysis focuses on criteria influencing age at transplantation (HSCT) and on the management of Hydroxyurea (HU) therapy across centers. The methodology of the registry has already been published (Le PQ et al., Pediatric Blood and Cancer, 2015) . Data are recorded prospectively from neonatal screening or first contact until last annual follow-up (FU) or death. The data collected included diagnosis, demography, treatment and outcome data as well as a minimal set of biological values. Data were extracted from the database in May 2021. There are 1029 patients registered by 14 different centers (2 centers exclusively treating adult patients). The median FU is 9 y (1-53 y). Median age at last FU is 13 y (0-61 y). 890 patients (86,5%) have a severe phenotype (SS or Sβ°) and 52% are female. Among them, 561 (55%) are born in Belgium of whom 379 (68%) are diagnosed by neonatal screening. In the absence of neonatal screening, median age at diagnosis is 1 year (range 0-18). 131 patients have been transplanted (126 successfully), 68 HSCT were performed before 2005. At last FU, 646 patients (76%) received at least 1 disease-modifying treatment (DMT) : 598 patients receive HU, 65 are chronically transfused, 8 participate in a study with crizanlizumab. The prescribed HU dose is known for 572 patients. 179 patients (31.3%) receive less than 20 mg/kg/day, 217 (37.9%) less than 25 mg/kg/day, 148 (25.9%) less than 30 mg/kg/day and 28 (4.9%) were prescribed more than 30 mg/kg/day. The majority of HSCT were performed in two centers (68 and 59, respectively). Median age at HSCT was significantly different between both centers (8y (2-15) versus 5y (0-19); p=0.002) (figure 1). Variables associated with a lower age at HSCT are detailed in table 1. In a linear multivariate regression model, birth in Belgium (p=0.002), no treatment with HU (p=0.009) and shorter duration of FU (p Among not transplanted patients, the proportion of those receiving HU is different between centers (50% to 91%; p=0.050). The median age at which HU was initiated was also significantly different between centers (4y to 21y; p Twenty-seven (2.6%) patients died which accounted for a mortality rate of 0.24/100 patients-years (PY) which increases significantly with age (0.18/100PY 40 years; p=0.001). Conclusions: BSR has an excellent registration activity from participating centers and represents a reliable tool to evaluate the Belgian SCD population. Mortality remains low with a significant trend to increase with age. Regarding treatment practices, the age at start of HU is significantly different between centers as the approach to further HU treatment, evaluated by ΔMCV. A higher dose of HU resulted in a higher ΔMCV. However, the policy to increase HU to maximal tolerated dose seems not implemented in most centers, as 2/3 of the patients are prescribed less than 25 mg/kg/day. Being born in Belgium and no treatment with HU are associated with younger age at HSCT. Nevertheless since 2005, almost all patients were treated with HU prior HSCT, reflecting the wider implementation of HU in SCD patients living in Belgium. Figure 1 Figure 1. Disclosures Benghiat: Novartis: Consultancy; BMS: Consultancy. Labarque: Bayer: Consultancy; Sobi: Consultancy; NovoNordisk: Consultancy; Octapharma: Consultancy; Novartis: Consultancy.

Several components of the clotting system are modified towards hypercoagulability in sickle cell disease (SCD). To date, hematopoietic stem cell transplantation (HSCT) is the only validated curative treatment of SCD. Here, we investigated the changes in the hemostatic potential of SCD children who&rsquo, ve received a successful HSCT. Seventeen children with severe SCD were enrolled in the study. Thrombin generation (TG) was performed on citrated platelet-poor plasma, obtained before and 3, 6, 9, 12 and 15 months after HSCT. TG was triggered using 1 pM tissue factor and 4 &micro, M phospholipids with or without thrombomodulin (TM). Before the HSCT, SCD children showed a higher endogenous thrombin potential (ETP), higher peak, higher velocity and shorter time-to-peak of TG than the normal controls (NC). ETP did not significantly change following the HSCT. However, the peak, velocity and time-to-peak of TG reversed to normal ranges from 3 months post-HSCT and remained so up to 15 months post-HSCT. The reduction of ETP after the addition of thrombomodulin (RETP) was dramatically reduced in SCD children before HSCT as compared with the NC. A partial reversal of RETP was observed from 3 months through 15 months post-HSCT. No statistical difference was observed for patient age or donor hemoglobinopathy status. In summary, successful HSCT improves the kinetics of TG but not the total thrombin capacity in SCD children.

Background Children with acute myeloid leukemia (AML) have a 70% survival rate with treatment regimens containing high doses of cytarabine and anthracyclines and, in some, hematopoietic stem cell transplantation (allo-HSCT). Procedure In this multicenter Dutch-Belgian protocol (DB AML-01), 112 children with de novo AML were included. Treatment was stratified according to day 15 bone marrow response after the first induction course. Poor responders received a second course without delay while good responders awaited hematological recovery. Patients achieving CR after two induction courses continued with three consolidation courses without HSCT in CR1. Results The overall remission rate was 93.5%. After a median follow-up of 4.1 years, three-year event-free survival (EFS) was 52.6% (95% CI, 42.9%-61.3%), three-year cumulative incidence of relapse 39.7% (95% CI, 30.1%-49.0%), and three-year overall survival (OS) 74.0% (95% CI, 64.8%-81.2%). Significantly more events occurred in patients with high WBC at diagnosis or FLT3-ITD/NPM1-WT, whereas core binding factor (CBF) leukemia had a significantly better EFS. KMT2A rearrangements and age > 10 years negatively impacted OS. Conclusions DB AML-01 response-guided therapy results in a favorable OS, particularly for children with CBF leukemia, children younger than 10 years or with initial WBC counts below 100 x 10(9)/L. Outcome of patients with FLT3-ITD/NPM1-WT remains poor and warrants alternative treatment strategies.

Background Asparaginase (Asp) and corticosteroid (CS) treatment in patients with acute lymphoblastic leukaemia (ALL) is associated with an increased risk of thrombotic events. Objective Characterization of global haemostatic phenotypes of patients with ALL during Asp therapy. Procedure Thrombin generation (TG) was monitored in platelet-poor plasma of 56 children treated for a B lineage ALL (36 with native, 20 with PEG Asp) using 1 pM tissue factor and 4 μM phospholipids, with and without thrombomodulin. Protein C activity (PC), free protein S (PS), antithrombin (AT) and fibrinogen levels were also measured. Results Elevated endogenous thrombin potential (ETP) and peak of TG were noted at diagnosis, throughout the Induction phase and Late Intensification but was significantly less for PEG than for native Asp (P < 0.001), while age, sex, type of corticosteroid during Induction and molecular response had no significant effect. The reduction of ETP after addition of thrombomodulin was significantly lower in ALL children compared with that in controls, suggesting impairment in PS/PC pathway. Three patients experienced thrombosis: two treated with native and one with PEG Asp. The two patients with native Asp had, at the time of thrombosis, a prothrombotic profile. Conclusions Treatment with Asp, in combination with CS, enhances TG in children with ALL, more significantly with native than PEG Asp, which is present early at diagnosis, persists during Induction and reappears during Late Intensification. This is consistent with the high incidence of thrombotic events described during these phases of therapy. The less pronounced effect of PEG Asp remains to be elucidated.

Bone marrow (BM) is the preferred graft source for hematopoietic stem cell transplantation (HSCT) in severe aplastic anemia (SAA) compared with mobilized peripheral blood stem cells (PBSCs). We hypothesized that this recommendation may not apply to those regions where patients present later in their disease course, with heavier transfusion load and with higher graft failure rates. Patients with SAA who received HSCT from an HLA-matched sibling donor from 1995 to 2009 and reported to the Center for International Blood and Marrow Transplant Research or the Japan Society for Hematopoietic Cell Transplantation were analyzed. The study population was categorized by gross national income per capita and region/countries into 4 groups. Groups analyzed were high-income countries (HIC), which were further divided into United States-Canada (n = 486) and other HIC (n = 1264); upper middle income (UMIC) (n = 482); and combined lower-middle, low-income countries (LM-LIC) (n = 142). In multivariate analysis, overall survival (OS) was highest with BM as graft source in HIC compared with PBSCs in all countries or BM in UMIC or LM-LIC (P < .001). There was no significant difference in OS between BM and PBSCs in UMIC (P = .32) or LM-LIC (P = .23). In LM-LIC the 28-day neutrophil engraftment was higher with PBSCs compared with BM (97% versus 77%, P = .002). Chronic graft-versus-host disease was significantly higher with PBSCs in all groups. Whereas BM should definitely be the preferred graft source for HLA-matched sibling HSCT in SAA, PBSCs may be an acceptable alternative in countries with limited resources when treating patients at high risk of graft failure and infective complications., SCOPUS: ar.j, info:eu-repo/semantics/published

For patients with acute lymphoblastic leukemia (ALL), allogeneic hematopoietic cell transplantation (alloHCT) offers a potential cure. Life-threatening complications can arise from alloHCT that require the application of sophisticated health care delivery. The impact of country-level economic conditions on post-transplantation outcomes is not known. Our objective was to assess whether these variables were associated with outcomes for patients transplanted for ALL. Using data from the Center for Blood and Marrow Transplant Research, we included 11,261 patients who received a first alloHCT for ALL from 303 centers across 38 countries between the years of 2005 and 2013. Cox regression models were constructed using the following macroeconomic indicators as main effects: Gross national income per capita, health expenditure per capita, and Human Development Index (HDI). The outcome was overall survival at 100 days following transplantation. In each model, transplants performed within lower resourced environments were associated with inferior overall survival. In the model with the HDI as the main effect, transplants performed in the lowest HDI quartile (n = 697) were associated with increased hazard for mortality (hazard ratio, 2.42; 95% confidence interval, 1.64 to 3.57; P, SCOPUS: ar.j, info:eu-repo/semantics/published

Objective To evaluate the survival of patients with sickle cell disease (SCD) recorded in the Belgian SCD Registry and to assess the impact of disease-modifying treatments (DMT). Method The Registry created in 2008 included patients of eight centers. All available data in 2008 were retrospectively encoded in the database. After 2008 and until 2012, all data were recorded prospectively for already registered patients as well as newly diagnosed subjects. Data were registered from neonatal screening or from diagnosis (first contact) until last follow-up or death. Data included diagnosis, demography, and outcome data. Results We collected data from 469 patients over a 5,110 patient years (PY) follow-up period. The global mortality rate was low (0.25/100 PY), although 13 patients died (2.8%) and was similar between children, adolescents (10–18 years), and young adults (P = 0.76). Out of the cohort, 185 patients received hydroxyurea at last follow-up (median duration of treatment: 10.3 years), 90 underwent hematopoietic stem cell transplantation (HSCT), 24 were chronically transfused, and 170 had never had any DMT. Hydroxyurea showed significant benefit on patients outcome as reflected by a lower mortality rate compared to transplanted individuals or people without DMT (0.14, 0.36, and 0.38 per 100 PY, respectively) and by higher Kaplan–Meier estimates of 15 year survival (99.4%) compared to HSCT (93.8%; P = 0.01) or no DMT groups (95.4%; P = 0.04). Conclusion SCD mortality in Belgium is low with no increase observed in young adults. Patients treated with hydroxyurea demonstrate a significant benefit in survival when compared to those without DMT or transplanted. Pediatr Blood Cancer © 2015 Wiley Periodicals, Inc.

Background L-asparaginase, a key therapeutic agent in the management of patients with acute lymphoblastic leukemia (ALL), dramatically impairs hepatic protein synthesis. We investigated the effects of prolonged exposure to L-asparaginase on antithrombin (AT), fibrinogen and mannan-binding-lectin (MBL) levels, and on the occurrence of thrombotic events (TE) and febrile neutropenia episodes (FN) in pediatric patients. Procedure Protein levels were measured in 97 children during 30 weeks of chemotherapy with L-asparaginase and up to 1 year following remission. TE and FN episodes were recorded during this period. Results Median AT level decreased from 0.96 IU/mL prior to treatment (range: 0.69–1.38) to 0.55 IU/mL (0.37–0.76) during therapy. Fibrinogen and MBL decreased from 3.18 g/L (1.29–7.28) and 1,177 ng/mL (57–5,343) to 1.56 g/L (0.84–2.13) and 193 ng/mL (57–544), respectively. All three proteins had recovered 1–4 weeks after L-asparaginase cessation. TE were reported in 22 (23%) patients. Of these, 11 occurred after a median of 10 administrations of L-asparaginase. Fifty-one FN were associated with infections, of which 36 occurred during treatment with L-asparaginase. Patients with low levels of MBL at diagnosis were at higher risk of FN associated with infections (RR = 1.59, 95%CI: 1.026–2.474). Both AT and MBL decreases were moderately correlated with fibrinogen (r = 0.51 and 0.58, respectively). Conclusions Children with ALL are exposed to significant decrease in AT, fibrinogen and MBL levels, and concomitant increased risk of thrombosis and FN with infection during L-asparaginase treatment. Measuring plasma levels of these liver-derived proteins could help predict the occurrence of adverse events. Pediatr Blood Cancer 2015;62:1381–1387. © 2015 Wiley Periodicals, Inc.

ObjectivesTo compare the outcomes of sickle cell disease patients diagnosed through neonatal screening with those who were not.MethodsIn an observational multicenter study in Belgium, 167 screened and 93 unscreened sickle cell disease patients were analyzed for a total of 1116 and 958 patient-years of follow-up, respectively. Both groups were compared with propensity score analysis, with patients matched on three covariates (gender, genotype, and central Africa origin). Bonferroni correction was applied for all comparisons.ResultsKaplan–Meier estimates of survival without bacteremia were significantly higher in the screened group than the unscreened group (94.47%; [95% CI, 88.64–97.36%] versus 83.78% [95% CI, 72.27–90.42%]), p = 0.032. Non-significant differences between both groups were reported for survival without acute chest syndrome, acute anemia, cerebral complication, severe infection, and vaso-occlusive crisis. Significantly lower hospitalization rate and days per 100 patient-years were observed in the screened compared with the unscreened group (0.27 vs. 0.63 and 1.25 vs. 2.82, p = 0.0006 and ConclusionThese data confirm the benefit of a neonatal screening programme in reducing bacteremia and hospitalization.

Despite improvements in medical management, sickle cell disease (SCD) remains associated with severe morbidity and decreased survival. Allogeneic haematopoietic stem cell transplantation (HSCT) remains the only curative approach. We report the outcome of 50 consecutive children with severe SCD that received HSCT in our unit between November 1988 and April 2013. The stem cell source was bone marrow (n = 39), cord blood (n = 3), bone marrow and cord blood (n = 7) and peripheral blood stem cells (n = 1). All patients had ≥1 severe manifestation: 37 presented with recurrent vaso-occlusive crises/acute chest syndrome, 27 cerebral vasculopathy and 1 nephropathy. The conditioning regimen consisted of busulfan + cyclophosphamide (BuCy) before November 1991 and BuCy + rabbit antithymocyte globulin after that date. Since 1995, all patients have been treated with hydroxycarbamide (HC) prior to transplantation for a median duration of 2·7 years. Median age at transplantation and median follow-up was 8·3 and 7·7 years, respectively. Acute graft-versus-host disease (GVHD) and chronic GVHD were observed in 11 and 10 patients, respectively. An excellent outcome was achieved, with 8-year overall survival and event-free survival (EFS) rates of 94·1% and 85·6%, respectively. Since HC introduction, no graft failure occurred and EFS reached 97·4%. Prior treatment with HC may have contributed to successful engraftment.

Newborn sreening (NS) for sickle cell disease (SCD) is effective in reducing early mortality and morbidity through education, prevention of infections and strategies to prevent stroke in children at risk of cerebral vasculopathy. Universal NS was implemented in all Brussels maternity wards since 2000. All identified children with SCD benefited from comprehensive medical care in dedicated centers. This retrospective study included all children with SCD diagnosed through NS and born between January 2000 and December 2005 (Group 1) and between January 2010 and December 2015 (Group 2) followed at Hôpital Universitaire des Enfants Reine Fabiola (Brussels, Belgium). Only patients whose parents consented to be recorded in the Belgian SCD database were eligible for this study. The aim of our study was to compare the outcome of 2 NS cohorts born at 10 years of interval. Demographic data, baseline hematological values and clinical events, occurrence of cerebral vasculopathy and prescription of disease-modifying treatments during the first 5 years of life were compared between both groups. Data were collected until March 1, 2019. 59 patients were identified for this study (35 in Group 1 and 24 in Group 2). Their characteristics are detailed in Table 1. Two patients in Group 2 did not completed the full 5-year evaluation period. Among these 59 patients, 77.9% patients developed at least one SCD clinical event before the age of 5. The number of patients who developed a specific clinical event as well as their age at this first event was the same between the 2 groups (Table 2). The hospitalization number and hospitalization days were not statistically different in the 2 groups (5 vs 4 hospitalizations during 5 years and 19 vs 17 days of hospitalization between Groups 1 and 2 respectively). 3 patients presented an overt stroke (1 in Group 1 and 2 in Group 2) with a global incidence of 1.02 stroke per 100 patient-years. No death was reported in both groups. The proportion of patients with abnormal transcranial doppler velocities decreased slightly in Group 2 (14.3% vs 8.3%, P=0.69) with more conditional velocities (5.7% vs 20.8%, P=0.10) but it was not statistically significant. 60% of patients in Group 1 were treated with hydroxyurea (HU) compared to 75% in Group 2 (P=0.27). HU was introduced at a median age of 2.5 (0.9-4.8) and 2.3 (0.8-4.8) in Groups 1 and 2 respectively (P=0.79). One patient from each group underwent an hematopoietic stem cell transplantation at 4.9 and 3.5 years. Hematological values were not different in the 2 groups excepted for platelets count, which were significantly lower in Group 2 (421 x 10³/µl vs 331 x 10³/µl, P=0.03). Moreover in patients under HU, platelet and reticulocytes count were statistically lower and HbF higher in Group 2 compared to Group 1 (Table 3). Nearly 80% of patients presented a clinical event before the age of 5. This is comparable to what is described in the literature. The Kaplan-Meier survival curves were not statistically different in both groups for the occurrence of a first dactylitis (P=0.52), a first vaso-occlusive crisis (P=0.22) and acute chest syndrome (P=0.37). No more difference was observed for acute anemia (P=0.43), severe infection (P=0.35) or patients under HU (P=0.40). Even if the number of patients on hydroxyurea is not statistically higher in Group 2, a better exposure to hydroxyurea is attested by the significant changes in some biological parameters. The limits of this study are the small size of our single center cohort and the exclusion of patients not recorded in the Belgian Registry because of lack of parental consent. This last point might create a bias by selecting patients whose parents are more prone to participate actively in the comprehensive care program. This periodic evaluation is essential to ensure the quality of care of patients and to measure possible changes in the management. Comprehensive care developed in our tertiary center had been already effective since 2000. Physicians not only tend to prescribe more hydroxyurea in young symptomatic patients, but also routinely adjust the dose to reach the maximal tolerated dose. Moreover adherence to treatment has been achieved through continuous education. Disclosures No relevant conflicts of interest to declare.

Ovarian insufficiency is a major long-term adverse event, following the administration of a myeloablative conditioning regimen, and occurring in >80% of children and adolescents receiving such treatment for malignant or non-malignant disease. Cryopreservation of ovarian tissue is currently offered to preserve the fertility of these young patients. At least 35 live births have been reported after transplantation of cryopreserved ovarian tissue in adult patients, but the procedure remains unproven for ovarian tissue harvested at a prepubertal or pubertal age. We report here the first live birth after autograft of cryopreserved ovarian tissue in a woman with primary ovarian failure after a myeloablative conditioning regimen as part of a hematopoietic stem cell transplantation performed for homozygous sickle-cell anemia at age 14 years. This first report of successful fertility restoration after the graft of ovarian tissue cryopreserved before menarche offers reassuring evidence for the feasibility of the procedure when performed during childhood.

A 12-year-old boy referred for severe hypereosinophilia (HE) presented fatigue, breathlessness, chest pain, night sweats, anorexia and weight loss for 3 weeks. He had no significant history except ...

Transient neonatal leukemia occurs almost exclusively in Down syndrome babies. We report here the unusual case of a newborn without Down syndrome who presented neonatal transient leukemia and who achieved spontaneously complete remission. Trisomy 21 and GATA1 mutation were both present in leukemic cells. While close follow-up is advised since true leukemia may develop later, the patient is still in remission for 2.5 years. We performed a literature review of 15 other similar cases. Conclusion: Our case of transient leukemia without Down syndrome and the literature review highlight the important role of trisomy 21 and GATA1 mutation in the development of transient neonatal leukemia.

Survival among children and adults with SCD in Belgium published in 2015 showed a low mortality rate (0.25/100 patient years (PY)) among the 469 patients included (5,110 PY) with no significantly increase above 18 years of age. Hydroxyurea (HU) had a positive impact on patients' survival rate when compared to those without disease-modifying treatments (DMT) or transplanted. This led us to compare the incidence of acute complications and hospitalizations among children and adults to see if significant change occurred. Complications before and after the age of 18 for 84 patients with severe genotype followed after 18 years of age and not transplanted for whom the data during childhood were recorded in the registry are detailed in Figure 1 and Table I. Data on the pre- and post-18 years' events for the entire severe genotype cohort are detailed in Table II and include data from the patients under 18 years and data at the pediatric age of those more than 18 years. Data was censored from the time of the transplantation. Furthermore, data from adult patients before age 18 and beyond with severe genotype treated or not with HU are given in Table III. There were 139 patients (1759 PY) more than 18 years who had at last follow up a median age of 21 years (range: 18-53 years). 42% (59/139) of the patients were treated with HU. The median number of vaso-occlusive crisis (VOC) was statistically lower during adulthood (0 vs 29.6/100 PY; p= 0.007) and the median number of acute chest syndrome (ACS) was not statistically higher in adult period compared to their follow-up during childhood. Overall, severe infections as well as hospitalizations number (19 vs 63/100 PY; p=0.0006) and days (119 vs 259/100 PY; p=0.021) are significantly higher in children. The comparison of adults under HU and without DMT showed a significant higher incidence of acute events in HU patients (Table III). This is true for follow-up in childhood and beyond the age of 18 (Table III). Patients without DMT obviously seems to have attenuated symptomatology (clinical phenotype not very severe despite their severe genotype) and were therefore not considered benefiting from DMT. In the latter, no ACS was recorded during their follow-up in adulthood (Table III). The increase in CVO and ACS incidence with age is well described in the literature but not found in our results. Higher number of hospitalizations and infections before 18 years of age are observed. This can be explained by the fact that children consult more quickly and frequently and they are more readily monitored in hospital compared to adults. They also live in community, which increases the risk of seasonal viral infections. Compared with data available in the literature, our adult patients, most of whom are treated with HU, have fewer acute complications. Nevertheless the comparison is jeopardized because of different methodological approaches. In addition, our cohort of adult patients is limited, has a relatively short follow-up and consists mainly of adults under 21 at the last follow-up. The shorter length of follow up and the underrepresentation of older adults who pay a heavier toll on SCD because of co-existence of chronic complications, may explain the reduced incidence of acute complications in our cohort. In conclusion, the incidence of events observed in our adult population is lower than that described in the literature. This difference is probably related to a larger proportion of HU patients in our cohort. But these results should be confirmed by data from a larger number of adult patients with longer prospective follow-up. Disclosures No relevant conflicts of interest to declare.

The six-minute walk test (6MWT) was introduced in adults and children suffering from pulmonary or cardio-vascular conditions to assess their sub-maximal functional exercise capacity. In sickle cell disease (SCD), a reduced 6-minute walk distance was observed in adults with chronic pain, hip avascular necrosis and osteopenia ; and in children with low hemoglobin level, low fetal hemoglobin, a baseline elevated TRV. In a previous study (Dedeken et al., PLoS One 2014), we also showed that abnormal 6MWT was significantly associated with the presence of silent infarct. The aim of our study is to explore the evaluation of the 6MWT over time and to confirm the correlation with the cerebral vasculopathy in a larger cohort. This study was conducted at Hôpital Universitaire des Enfants Reine Fabiola (Brussels, Belgium) and included SCD children older than 6 years, regularly followed between 2011 and 2017 and who had at least two 6MWT. The age-standardized predicted value of the 6-minute walk distance (6MWD) was established as reported by Geiger. The 6MWT was considered as normal if the 6MWD was more than 80% of the age-standardized predicted value. Baseline hematological values, clinical events, cerebro-vascular disease, cardio-pulmonary parameters and disease-modifying treatment (DMT) were compared between those with normal and abnormal 6MWT and according to the 6MWD and between the 1st and the 2nd 6MWT overtime. 118 patients have been assessed twice and had at first evaluation a 6MWD of 90.6% (Range 49-119%), with an abnormal test found in 5.1%. The characteristics of the patients are detailed in the Table 1. The changes of the 6MWD and the biological data over time are detailed in Table 2. After 4 years of follow-up, 77.1% of patients were treated with Hydroxyurea (HU) and 16.6% patients were chronically transfused. In parallel with the increased HU prescribing rate, we have observed a significant increase of the Hb and the MCV and a decrease of reticulocytes and hemolysis parameters. The first 6WMT was performed at the median age of 10.3 years and the last one at the median age of 14.1 years. The median 6MWD increased over time including for non-chronically transfused patients. Girls performed less well in the 6MWT (93% for girls vs. 95.7% for boys; P = 0.03). Acute chest syndrome was significantly more frequent in boys (62%) compare to girls (38.7%). Nevertheless, no other differences were founded between boys and girls regarding biological values, clinical events or DMT. 26.5% of our patients have silent infarcts at a median age of 14.6 years. The 6MWD was the same in patients with and without silent infarcts (92.5% vs. 95% ; P=0.17) even when chronically transfused patients were excluded (94% vs. 95% ; P= 0.20). Patients with silent infarcts have a significant lower hemoglobin level and higher reticulocytes count, neutrophils count, LDH and MCV. In conclusion, the 6MWD observed in our cohort characterized by a very high rate of HU treatment is much higher than published in others series and improved over time. With only 5% of SCD patients having a 6MWD < 80% of the normal predicted value at last evaluation, we were not able anymore to confirm a correlation between the presence of silent infracts and abnormal 6MWT. Disclosures No relevant conflicts of interest to declare.

BACKGROUND Hydroxyurea (HU) reduces the severity of sickle cell disease (SCD) in children; nevertheless, its long-term safety is an important concern. This paper evaluates HU genotoxicity at dose ≤ 30 mg/kg/day after over 2 years of treatment. PROCEDURE The study included 76 children: 32 SCD patients treated with HU, 27 SCD patients not treated with HU, and 17 unaffected children. HU patients were classified as good or poor responders according to their clinical response. Comet assay allows the comparison of DNA damage between both groups of patients and unaffected children. Maximal concentration (Cmax ) of HU in plasma was determined after drug administration. RESULTS Mean values of DNA in the comet tail were 5.13 ± 6.84 for unaffected children, 5.80 ± 7.78 for patients with SCD treated with HU, and 5.61 ± 6.91 for patients with SCD not treated with HU. Significant differences were observed between unaffected children and children with SCD. No difference was evident between comets from SCD patients treated and not treated with HU. In the case of HU, mean DNA in the comet tail was significantly lower in good responders than in poor responders: 5.54 ± 7.77 and 6.69 ± 8.43, respectively. Mean Cmax value on plasma was 39.08 ± 15.65 mg/l; N = 31. CONCLUSIONS SCD increases, slightly but significantly, DNA damage in lymphocytes from patients with SCD. Patients with SCD treated with HU do not present more nucleoid damage than patients with SCD not treated with HU. Good responders to the HU treatment have significantly less nucleoid damage than poor responders. HU treatment at ≤30 mg/kg/day does not expose patients to a genotoxic plasma concentration.

Ovarian insufficiency is a major long-term adverse event, following the administration of a myeloablative conditioning regimen, and occurring in80% of children and adolescents receiving such treatment for malignant or non-malignant disease. Cryopreservation of ovarian tissue is currently offered to preserve the fertility of these young patients. At least 35 live births have been reported after transplantation of cryopreserved ovarian tissue in adult patients, but the procedure remains unproven for ovarian tissue harvested at a prepubertal or pubertal age. We report here the first live birth after autograft of cryopreserved ovarian tissue in a woman with primary ovarian failure after a myeloablative conditioning regimen as part of a hematopoietic stem cell transplantation performed for homozygous sickle-cell anemia at age 14 years. This first report of successful fertility restoration after the graft of ovarian tissue cryopreserved before menarche offers reassuring evidence for the feasibility of the procedure when performed during childhood.

To evaluate the survival of patients with sickle cell disease (SCD) recorded in the Belgian SCD Registry and to assess the impact of disease-modifying treatments (DMT).The Registry created in 2008 included patients of eight centers. All available data in 2008 were retrospectively encoded in the database. After 2008 and until 2012, all data were recorded prospectively for already registered patients as well as newly diagnosed subjects. Data were registered from neonatal screening or from diagnosis (first contact) until last follow-up or death. Data included diagnosis, demography, and outcome data.We collected data from 469 patients over a 5,110 patient years (PY) follow-up period. The global mortality rate was low (0.25/100 PY), although 13 patients died (2.8%) and was similar between children, adolescents (10-18 years), and young adults (P = 0.76). Out of the cohort, 185 patients received hydroxyurea at last follow-up (median duration of treatment: 10.3 years), 90 underwent hematopoietic stem cell transplantation (HSCT), 24 were chronically transfused, and 170 had never had any DMT. Hydroxyurea showed significant benefit on patients outcome as reflected by a lower mortality rate compared to transplanted individuals or people without DMT (0.14, 0.36, and 0.38 per 100 PY, respectively) and by higher Kaplan-Meier estimates of 15 year survival (99.4%) compared to HSCT (93.8%; P = 0.01) or no DMT groups (95.4%; P = 0.04).SCD mortality in Belgium is low with no increase observed in young adults. Patients treated with hydroxyurea demonstrate a significant benefit in survival when compared to those without DMT or transplanted.

The efficacy of hydroxyurea in hemoglobin SC (HbSC) patients is not well documented. We describe the long-term response to hydroxyurea in children with clinically severe HbSC. In 15 patients, hydroxyurea resulted in a significant increase in mean corpuscular volume (MCV) and fetal hemoglobin (HbF) and a significant decrease in episodes of acute chest syndrome and hospitalization for pain; there was no effect on hemoglobin level. The most significant side effect was thrombocytopenia, which led to discontinuation of treatment in one patient. This study suggests that hydroxyurea has efficacy and is safe for long-term therapy in patients with HbSC.

L-asparaginase, a key therapeutic agent in the management of patients with acute lymphoblastic leukemia (ALL), dramatically impairs hepatic protein synthesis. We investigated the effects of prolonged exposure to L-asparaginase on antithrombin (AT), fibrinogen and mannan-binding-lectin (MBL) levels, and on the occurrence of thrombotic events (TE) and febrile neutropenia episodes (FN) in pediatric patients.Protein levels were measured in 97 children during 30 weeks of chemotherapy with L-asparaginase and up to 1 year following remission. TE and FN episodes were recorded during this period.Median AT level decreased from 0.96 IU/mL prior to treatment (range: 0.69-1.38) to 0.55 IU/mL (0.37-0.76) during therapy. Fibrinogen and MBL decreased from 3.18 g/L (1.29-7.28) and 1,177 ng/mL (57-5,343) to 1.56 g/L (0.84-2.13) and 193 ng/mL (57-544), respectively. All three proteins had recovered 1-4 weeks after L-asparaginase cessation. TE were reported in 22 (23%) patients. Of these, 11 occurred after a median of 10 administrations of L-asparaginase. Fifty-one FN were associated with infections, of which 36 occurred during treatment with L-asparaginase. Patients with low levels of MBL at diagnosis were at higher risk of FN associated with infections (RR = 1.59, 95%CI: 1.026-2.474). Both AT and MBL decreases were moderately correlated with fibrinogen (r = 0.51 and 0.58, respectively).Children with ALL are exposed to significant decrease in AT, fibrinogen and MBL levels, and concomitant increased risk of thrombosis and FN with infection during L-asparaginase treatment. Measuring plasma levels of these liver-derived proteins could help predict the occurrence of adverse events.

Pediatric data regarding cytomegalovirus (CMV) infections in pediatric patients receiving umbilical cord blood (UCB) transplantation are sparse.To determine whether UCB transplantation increases the risk of CMV infection and disease compared with other graft sources.The medical files of patients who underwent allogeneic hematopoietic stem cell transplantation at CHU Ste-Justine (Montreal, Quebec) from April 2000 to December 2006 were retrospectively reviewed. A Cox proportional hazard model was used to assess the effect of potential predictors of outcomes.A total of 176 patients with a median age of nine years (range 0.1 to 18 years) underwent hematopoietic stem cell transplantation. The source of stem cells were UCB, bone marrow and peripheral blood stem cells in 86, 86 and four of the cases, respectively. CMV infection occurred in 29 patients (16%). At day 100 post-transplantation, the rate of CMV infection was 13% in UCB transplant recipients (11 of 86) versus 20% in those with other sources of graft (18 of 90) (P=0.19). Positive CMV serology of the recipient and leukocyte depletion were two independent variables associated with an increased risk of CMV infection. Among infected patients, six developed CMV disease (20.7%). The rate of CMV disease one year after infection was 49% in patients who received UCB (five of 11) and 6% in others (one of 18). This difference was significant by univariate (P=0.01) but not by multivariate analysis.In the setting of the current study, with a moderate CMV infection rate (16.5%), UCB transplantation did not appear to increase the risk of CMV infection and disease.Il existe peu de données pédiatriques sur les infections à cytomégalovirus (CMV) chez les patients pédiatriques qui reçoivent une greffe de sang du cordon ombilical (SCO).Déterminer si la greffe de SCO accroît le risque d’infection à CMV par rapport à d’autres greffes.Les chercheurs ont procédé à une analyse rétrospective des dossiers médicaux de patients qui ont subi une greffe de cellules souches hématopoïétiques au CHU Sainte-Justine de Montréal, au Québec, entre avril 2000 et décembre 2006. Ils ont utilisé un modèle de risque proportionnel de Cox pour évaluer l’effet des prédicteurs potentiels d’issues.Au total, 176 patients ayant un âge médian de neuf ans (plage de 0,1 à 18 ans) ont subi une greffe de cellules souches hématopoïétiques. Les cellules souches provenaient du SCO, de la moelle épinière et du sang périphérique dans 86, 86 et quatre cas, respectivement. Une infection à CMV s’est manifestée chez 29 patients (16 %). Au 100Dans le cadre de la présente étude, où le taux d’infection à CMV était modéré (16,5 %), la greffe de SCO ne semblait pas accroître le risque d’infection et de maladie à CMV.

Introduction Cerebral angio-MRI is required in children with Sickle Cell Disease (SCD) in case of abnormal blood flow velocities or lack of acoustic window at Trans-Cranial Doppler Echography (TCD) and to screen the presence of silent infarcts. MRI in young children requires deep sedation and could potentially lead to hypoxemia and increase the risk of SCD-related complications. For this reason, we studied whether deep sedation (DS) for cerebral MRI in young children with SCD might be associated with more frequent adverse events during and within 30 days after the procedure. Methods We identified all patients with SCD who were investigated by MRI under DS in our center (Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium) from Augustus 2005 to March 2016. Demographic data as well as data about the anaesthetic procedure and acute clinical events 30 days before and after sedation have been collected retrospectively. The anaesthetic procedure for patient with SCD was based on midazolam as premedication followed by propofol for deep sedation. Supplementary oxygen was added to all children to maintain FiO2 > 40%. No prophylactic red blood cell transfusion/exchange were administered before sedation. Data were analyzed for normality; parametric values were assessed by mean and SD, non-parametric values were assessed as medians and interquartile ranges. Student test was used to analyse continuous variable and Chi-square test for discrete variable. Results Seventy four SCD children were identified in whom 147 procedures were performed. 53% were female; 94% were HbSS or HbSβ0. Most of them have already experienced one or more previous acute clinical event (dactylitis 32.4%, vaso-occlusive crisis [VOC] 45.9%, acute chest syndrome [ACS] 32.4%). Hydroxyurea has been prescribed to 39 patients (52.7%) at a median age of 2.4 years (range: 0.6- 4.9 years) mainly for recurrent VOC/ ACS. Five patients were on chronic transfusion program beginning at a median age of 2.6 years (range: 2.1-4.7 years) for primary and secondary stroke prevention. Median age at procedure was 3.1 years (range: 0.9 - 6.1 years). The median number of MRI under DS per patient was 1.8 (range: 1-5). Seven MRI were associated to an incident linked to the DS: 3 episodes of agitation/irritability, 4 desaturations < 95% (with 1 requiring transient manual mask ventilation). Median saturation during the procedure was 100% (range: 84-100%). 28 clinical events (19%) occurred within the 30 days before DS while 16 (11%) occurred within the 30 days after DS. Considering hospitalisations, the number were 16 (11%) and 11 (7.5%) before and after respectively. Considering only VOC and ACS, the numbers were 8 (5.4%) before and 6 (4%) after DS. Patients developing SCD complications after DS were less frequently treated with hydroxyurea (18.8% vs. 44.3%, P=0.06), had longer procedure while Hb level, WBC count, MCV, HbF and LDH were not significantly different. Discussion Deep sedation with midazolam and propofol for Cerebral angio-MRI in SCD children was safe, with few side-effects and no increase of VOC and ACS within one month of sedation. Only one study analyzed the safety of deep sedation in young children with SCD (Belmont et al. J Pediatr May 2015; 166:1226-32) but reported a possible trend of increased complications after sedation with midazolam, phenobarbital and fentanyl. Compared to the series of Belmont (Table 1), our patients were younger, more often treated with hydroxyurea and had a shorter procedure duration with less deep desaturation. The combination of propofol with midazolam seems to be better tolerated by children with SCD than midazolam, pentobarbital and fentanyl and appears to be safe in very young children. Disclosures No relevant conflicts of interest to declare.

Introduction Despite reduction of mortality during childhood, young adults with SCD are at higher risk of morbidity and mortality after transition from paediatric to adult care, mainly in the US. To evaluate our transition system, we have studied the outcome of patients beyond the transition to adult care and looked if it was associated with an increase in vaso-occlusive crisis (VOC) and acute chest syndromes (ACS), the occurrence of progressive organ damage and changes in hydroxyurea prescription. Patients and Methods This study focus on sickle cell disease patients, born after January 1, 1980 and who have been transitioned from pediatrics (Hôpital Universitaire des Enfants Reine Fabiola, HUDERF) to adult care (CHU Brugmann), followed for minimum 2 years at HUDERF and having transitioned at least 2 years before December 2015. Demographic data, genotype, disease modify therapies, biological data, clinical data, acute clinical event, 6 minutes-walk test, cardiac echography) were collected retrospectively. Patients who underwent a hematopoietic stem cell transplantation were excluded from the analysis. Student test was used to analyse continuous variable and Wilcoxon regression for paired sample. Mc Nemar's test was used for comparison of paired nominal data and Chi-square test when data missed. Results The comparison of the data before and after transition is detailed in Table 1. Thirty eight patients (11 males) were included and made the transition at a median age of 20.1 years (range: 18.0-26.8). All patients were HbSS. The median age at diagnosis was 0.8 year (range: 0-7.95). The median duration of the follow-up before the transition was 15.95 years (range: 3.3 - 25.2) and after transition was 4.7 years (range: 2.2-5.8 years), accounting for 552.15 and 159.61 patient-years (PY) of follow-up respectively. Two patients died, 5.2 years and 0.6 year after the transition respectively. The death rate after transition was of 1.25/100 PY. Four women have delivered after a median gestation of 37.1 weeks (range: 35.9-38.7 weeks). The median new-born weight was 2.9 kg (range: 2.4-3.4 kg). The rate of disease modifying therapies remains stable after the transition. 33 patients were treated with hydroxyurea before transition compared to 35 after transition. Four patients were on chronic transfusion program before and 6 after transition. Hematological data were not statistically different at time of transition when compared to last follow-up, suggesting stable compliance to therapy but creatinine level increased significantly. VOC and ACS rate did not increased after transition as well as hospitalisation rate and days of hospitalisation. Tricuspid regurgitation velocity (TRV) increased significantly over the time but no patient developed pulmonary hypertension. The 6-minutes walk distance decreased significantly. Systolic and diastolic blood pressure increased significantly between the time of transition and the last follow-up. Regarding the educational status (8 data missing), 21 (70%) patients were able to reach graduate school and only 4 were not able to finish high school. Conclusion Our data provide useful information on the outcome during the years after transition. No increase in hospitalizations, VOC or ACS was observed. This is very different from the data provided by Blinder et al. One of the reason could be that comparing to the US situation, the Belgian Health Care System provide access and quality of healthcare even in underprivileged population. The prescription rate of HU remained unchanged and the compliance to treatment evaluated by hematological parameters remained stable. Nevertheless, changes in cardio-vascular parameters and creatinine levels suggest that despite the well-standardized follow-up for young adult patient with sickle cell disease, progressive organ damage leading to renal and cardio-vascular disease might not be prevented. However, compared to the literature, we have found less high level of TRV (9.7% vs. 24-45%), no patient with pulmonary hypertension (compared to 6-10%). In addition, our patients seems to have a better 6-minutes walk distance even in the childhood cohort (paediatrics data : 562m vs. 491m in Waltz study; adults data : 490m vs. 398m). Additional data from a larger number of patients as well as a longer period of follow-up are required to confirm the efficacy of our transition system. Disclosures No relevant conflicts of interest to declare.

Background: Contemporary treatment schedules for pediatric acute myeloid leukemia (AML) have improved 5 year-overall survival rates up to 70% . These schedules usually consist of 4 to 5 intensive courses mainly based on cytarabine (AraC) and anthracyclines, with allo-HSCT upfront in a subset of patients . Long-term side effects such as late cardiotoxicity caused by high cumulative anthracycline dosages are a major concern. Therefore, the DCOG/BSPHO collaboration adapted the NOPHO 2004 protocol to DB-AML01 to reduce cumulative anthracyclines from 420-450 mg/m² to 300-330 mg/m² and to omit HSCT in CR1. Material: The treatment consisted of 5 chemotherapy courses: first induction course AIET (AraC conventional dose and Idarubicin (Ida) 36 mg/m2); second induction course AM (AraC conventional dose and Mitoxantrone (Mitox) 30 mg/m2) when blasts at day 15 < 5% or FLA-DNX (high dose AraC and Daunoxome (DNX) 180 mg/m2) when blasts > 5% at day 15 or t(8;21) AML; 3 consolidation courses (high dose AraC with Etoposide as course 3 and 5 and in between high dose AraC alone). Cumulative dose of AraC is 43,4 gr/m2 and of anthracyclines 300 mg/m² for patients receiving AIET+AM or 330 mg/m² for patients receiving AIET/FLA-DNX. Results: From 2010 to 2014 a total of 113 children with AML, median age 6.0 yrs (range 0-16), gender 56 males, were included. Second induction course was AM in n=75 and FLA-DNX in n= 33. Death in induction occurred in 4 patients, CR rate was 102/113 (90.3%) and 7 patients were refractory after induction. The later events were death in CR (n=2), relapse in CR (n=40), and secondary malignancies (n=0). HSCT was given to 3 patients in CR1 (physician's decision). Median follow up time is 2.6 years (range (range 1-5). Probability of EFS at 2 years was 60% (95% CI 49-69%) and 2-yr OS was 76 (95% CI 66-83%)77.9%. Especially inv 16 (n=10) and t(8;21) AML (n=16) had an excellent outcome (inv 16:2-yr EFS: 70% (95% CI 32-89%) and 2-yr OS 91% (95% CI 51-99%) resp t(8;21):2-yr EFS: 87% (95% CI 57-97%) and OS: 94% (95% CI 63-99%)), EFS nor OS in other genetic subgroups such as FLT3-ITD and MLL rearrangements were significantly different from the total group. Children with an older age (> 10 years) (n=34) or high WBC count (>50.109/l) (n=41) had the poorest 2-yr EFS: 51 (95% CI 33-67%) resp EFS: 40% (95% CI 24-56%), whereas OS was not significantly worse. For the patients with a relapse, 32 achieved a second CR and 4 a partial remission (90%) . In second CR 34 patients received an allo-HSCT. Until now 26 of the 40 patients are still in second CR. Conclusion: The DB-AML01 outcome data suggest that the choice of high cumulative doses of AraC with moderate cumulative doses of anthracyclines up to 300-330 mgr/m² results in a favorable overall survival for particularly those children with t(8;21), inv (16) AML, young age or lower WBC counts. Children with relapsed AML could be rescued with second line treatment and allo-HSCT. These results underscore the relevance of identification of subgroups of pediatric AML patients, based on age, WBC count and t(8;21) or inv 16, curable with "lower risk" treatment arms without allo-HSCT in CR1. Disclosures Kaspers: Janssen-Cilag: Research Funding.

Pain resulting from sickle-cell vaso-occlusive crisis (VOC) is often severe, prolonged and difficult to alleviate. Guidelines based on scientific evidence are lacking. In order to evaluate the effectiveness of our treatment protocol, we performed a population-based retrospective observational study on HbSS sickle-cell patients (n=22) admitted for severe VOC (n=48) during a 30-months period and managed with patient controlled analgesia (PCA). Median (10 th -90 th percentiles) visual analogical pain scale (VAS) at admission was 9.5(7–10). Patient received 0.3mg/kg (0.1–0.4) intravenous morphine at admission, then PCA was started with the following settings: continuous rate: 20 µg/kg/h (10–25), bolus: 25µg/kg (21–32), and 1.8 bolus allowed/hour (1.7–2.8). Six hours after admission, VAS was less than 7 in only 41% of cases. The median VAS declined steadily during hospitalization. Pain intensity was not correlated with morphine dosage. Success 6 hours after admission (VAS 2 CVO/year have the following characteristics: higher VAS at admission, higher morphine dosages, lower success rate and lower CRP, bilirubin, LDH and reticulocyte count. The difficulties encountered in the management of patients who experienced >2 VOC/year may be related to their genotypic particularities. For such patients, an increase of morphine dosage is required. We have developed a computer routine in order to reduce time and increase accuracy of PCA prescription, and to build a prospective database that enables continuous assessment of our treatment protocol.

Introduction: Genetic counseling in sickle cell disease (SCD) allows to inform people about the genetic condition and to make informed decisions about screening and treatment opportunities. With improvement of care and follow-up of SCD and in order to provide adequate genetic counseling, the current study compared the clinical presentation of patients with hemoglobin SC disease (SC) and sickle cell anemia (SS) or SBeta°-thalassemia (Sβ°). Methods: The Belgian SCD Registry currently includes patients followed in 8 centers. Data was retrieved retrospectively from their medical charts until 2008. From 2008 till December 2012, all data (known and new cases) was prospectively entered. Data was collected either from birth, for patients diagnosed by means of the neonatal screening program (NSP) or from diagnosis following the first contact in a center and consistently until the last follow-up (FU) visit, or death. Data included genotype, demography, method and date of diagnosis, SCD-related complications, biological parameters, radiological results, treatment and hospitalizations. Results: Among the 469 patients recorded, 36 (8%) were SC. Their demographic and outcome data are given in Table 1, subgroups of SC patients detected at birth or not are given in Table 2. FU was 292 and 4749 patient-years (PY) for SC and SS/Sβ° groups respectively. Median age at diagnosis for SC and SS/Sβ° subgroups not detected at birth was 6.7 and 2.6 y. The first vaso-occlusive crisis (VOC) in SC patients occurred earlier in neonatal screened patients (5y vs 17y; P=0.004). Osteonecrosis was observed only in 6 patients diagnosed at birth but was significantly more frequent in SC individuals (P=0.02). Among the 6 SC patients treated with hydroxyurea (HU), indications for treatment were recurrent VOC (n=4), proteinuria (n=1) and osteonecrosis (n=1). Hospitalization days per 100 PY were 123 for the SC NSP cohort and 373 for the SS/Sβ° NSP cohort, with total hospitalization days significantly lower in SC patients (160 vs. 4059 days ; P=0.03). Discussion: SC patients represent 8 % of the whole cohort but asymptomatic and undiagnosed patients probably exist. Overall they are much less represented than in other Western series. They are significantly less affected by VOC, acute chest syndrome (ACS), severe anemia than SS/Sβ° patients but did not differ for occurrence of retinopathy or osteonecrosis. Several published studies confirmed these data but showed also others complications such as severe infection, stroke and death. Our data doesn’t support any impact of NSP on occurrence of major complications for SC disease. Retinopathy incidence that increases with age is as expected lower in the NSP group (younger patients at last FU when compared to no NSP group). Older age at first VOC in the no NSP group results probably from previously undiagnosed mild disease. Nevertheless several SC patients were more severely affected requiring HU treatment. Limitations of our work are linked to the small size of our SC cohort, the nature of the partial retrospective study and the unknown number of SC patients not requiring care in a specific program. In conclusion, SC patients have a lower incidence of clinical events than SS/Sβ°, excepted for osteonecrosis and retinopathy equally observed in both groups. Our data support the need of early ophthalmological FU and special awareness to detect early osteonecrosis. These Belgian data may support a dedicated genetic counseling for SC patients and affected families. Table 1. SC and SS/S β 0 patients: demographic and outcome SC SS/Sβ0 P Number of patients 36 (8%) 423 (90,2%) Male 14 (39%) 201 (48%) NS NSP 19 (53%) 142 (34%) Median age at diagnosis years (range) 0 (0-35) 1 (0-29) NS Median age at last FU years (range) 9,9 (1,4-44) 13 (1-53) NS Severe anemia < 60g/L 3 (8%) 208 (49%) < 0,01 ACS 1 (2,8%) 119 (28%) < 0,01 VOC 11 (31%) 253 (60%) < 0,05 Stroke 0 17 (4%) NS Severe infection 0 35 (8%) NS Osteonecrosis 4 (11%) 36 (8,5%) NS Retinopathy 4 (11%) 25 (6%) NS HU treatment 6 (17%) 179 (42%) < 0,05 Deaths 0 13 (3%) NS Table 2. SC patients from NSP vs no NSP: demographic and outcome NSP no NSP P Number of patients 19 (53%) 17 (47%) Male 10 (53%) 4 (24%) NS Median age at last FU years (range) 6 (1-14) 14 (4-44) NS Severe anemia < 60g/L 2 (10,5%) 1 (6%) NS ACS 0 1 (6%) NS VOC 5 (26%) 6 (35%) NS Osteonecrosis 3 (16%) 1 (6%) NS Retinopathy 0 4 (23,5%) 0,04 Disclosures No relevant conflicts of interest to declare.

Chronic transfusion in sickle cell disease (SCD) remains the gold standard therapy for primary and secondary stroke prevention and is indicated for patients with recurrent severe vaso occlusive crisis (VOC) or acute chest syndrome (ACS). Automatized apheresis (AA) has several advantages compared to manual exchange transfusion (MET): shorter procedure, continuous control of fluid balance, etc. The aim of our study was to assess the safety and efficacy of AA in SCD patients previously treated with MET at Hôpital Universitaire des Enfants Reine Fabiola, Brussels, Belgium and to evaluate the change of the costs related to transfusion and chelation overtime. From January 2012, the AA program for SCD patients started in our institution. Patients on chronic transfusion program (CTP) and previously treated with MET were eligible to switch to AA if sufficient peripheral venous access to allow AA without the use of central venous line and if weight ≥ 30kg. On CTP, target HbS was Ten patients switched from MET to AA at a median age of 11.8 years (range, 9.6-16.8y). The median duration of MET before start of AA was 1.9 years (range 0.5-4.4y). The median duration of AA was 1.7 years (range 1-2.4y). Four patients are on AA for > 2 years, 4 ≥ 20 months and 2 > than 12 months. Indications for CTP were overt stroke (2), pulmonary hypertension (2), recurrent VOC/ACS (5) and poorly tolerated severe anemia (1). All patients remained stable without any SCD related event, except one child who presented seizures without evidence of new stroke and for whom anticonvulsivant therapy was resumed. HbS level remained in the target values for all patients despite a slightly but significantly higher value on AA. The ferritin level and the duration of the procedure decreased significantly (Table 1). The 2 patients on iron chelation stopped it after 10 and 1 AA procedures. Interval between 2 AA was significantly longer than on MET (P AA is useful and safe for SCD patients requiring exchange transfusion program. It is less time consuming for nurses and patients, improves iron overload and interval between 2 procedures is significantly reduced. Despite higher costs related to the increase packed RBC requirement, the costs of AA and MET in the Belgian Health Care System are the same as chelation could be stopped in previously treated patients. Abstract 4091. Table 1.Changes in age, weight, biological data and procedure parameters on MET and on AA On METOn AAP value 1st year 2nd yearMedianRangeMedianRangeMedianRangeMedian age (years)11,89,7-16,812,810,8-17,713,311,8-18,6 Disclosures No relevant conflicts of interest to declare.

In Western countries, mortality among patients with sickle cell disease (SCD) has decreased in the last decades by means of neonatal screening (NS), infectious prophylaxis and care improvements. The major causes of death in children include acute chest syndrome, sepsis, splenic sequestration, stroke, aplastic crisis while in adults end-stage organ failure contributes also to premature death. Hydroxyurea (HU) and stem cell transplantation (SCT) are used in Belgium for more than 20 years but their possible influences on survival have not been yet analyzed. The Belgian SCD Registry was created in 2008 including patients of 8 centres. All available data in 2008 were retrospectively encoded in the database. After 2008 and until 2012, all data were recorded prospectively for already registered patients as well as newly diagnosed subjects. Data were registered from NS or from diagnosis (first contact) until last follow up (FU) visit, SCT or death. Data included diagnosis, demography and outcome data. After SCT, only vital status and cause of death were recorded. Up to date, data from 470 pts are recorded (224 males), 412 are HbSS, 14 HbSβ0, 7 HbSβ+ and 37 HbSC. The median age at diagnosis and at last FU was respectively 0.7 year (y) and 9.9 y. The FU for the whole cohort was 3810 patient-years (PY) and with 136 patients aged over 18y, their FU during adulthood accounted for 520 PY. Thirteen patients died (2.8%). The mortality per 100-PY was 0.34 and the median age at death was 14.5 y (range, 1.5-23.7 y). All deaths occurred in HbSS patients, 5 after SCT and 8 due to an acute event. Complete data set is missing for 3 of the 8 patients. For the 5 well documented SCD related deaths, causes were: hemorrhagic stroke (2), sepsis due to S. pneumoniae (1), aplastic crisis (1) and infection during stay in homeland (1). At last FU, 91 patients were transplanted, 182 were on HU, 7 on HU + chronic transfusion (CT), 19 on CT (4 after HU treatment). The remaining 171 patients never had disease modifying therapy (DMT). Compared with the latter, mortality rate for those on HU was significantly reduced (0.1 vs 0.5/100-PY) while patients on HU have longer FU and are older at last FU (Table 1). Among 91 patients transplanted at a median age 6.9 y, 5 died: 3 from acute transplant related toxicity, 1 from secondary acute myeloblastic leukemia after cGVHD, and 1 is unexplained more than 7 years post SCT. The data issued from the most recent NS cohorts report a low death rate during childhood ranging from 0.13 to 0.52. Even if our Belgian cohort is not exclusively issued from neonatal diagnosis, the observed death rate is low (0.34/100-PY). Several methodological biases are present in this partially retrospective study (incomplete or unavailable data, lost of FU, no information if death occurred before the first contact in a center, …). Nevertheless our low mortality is not underestimated since 1) most patients were followed since infancy and during a long period (3810 PY); 2) the FU during adulthood (period of increased mortality) accounted for 520 PY; 3) our cohort represents a very large part of the Belgian SCD population since a national inquiry performed in 2007 estimated the whole SCD population to 500. The effect of HU on mortality has been reported in adults and more recently in children. Despite longer FU and older age at last FU, our data confirms those previously results With only one case, death by infection is rare while SCT complications contributed to about 40 % of deaths. Even if SCT is the only curative option for SCD, it encompasses a risk of mortality. As life expectancy of SCD patients has been extended which is confirmed by our results (especially for patients on HU), SCT should be reserved for clinically severe cases. Population-based prospective studies evaluating the survival in transplanted and non transplanted patients are needed. Disclosures: No relevant conflicts of interest to declare.

Asparaginase (Aase) and corticosteroid (CS) used to treat acute lymphoblastic leukemia (ALL) in children during the Induction and Late Intensification phases have adverse effects on coagulation and increase the incidence of thrombotic events. Aase and CS reduce both pro- and antithrombotic factors and most studies have evaluated the individual components of the coagulation system to infer the prothrombotic profile. However, global haemostatic potential of these children and its changes during treatment are poorly reported. We aimed to characterize the global haemostatic phenotype of ALL patients during native Aase therapy, using a global haemostatic assay, the Calibrated Automated Thrombogram® (CAT) method of thrombin generation (TG) in B lineage ALL children treated according to the latest CLG-EORTC first-line protocol (a BFM derived protocol). CAT method was performed on platelets-poor plasma (PPP) at diagnosis (day 1), before each Aase infusion (8 during Induction and 4 during Late Intensification), and at distance of Aase infusion (during and after Interval Therapy and at start of Maintenance). TG was triggered using 1pM tissue factor (TF) and 4µM phospholipids (PL), with and without addition of thrombomodulin (TM). Endogenous Thrombin Potential (ETP) and Peak were monitored and the interquartile range was compared to the [2,5 – 97,5] percentile range of normal controls (NC) of the same range of age (n=28). Protein C activity (PC), free Protein S (PS), antithrombin (AT) and fibrinogen levels were also measured. Results Thirty six children were included (20 boys and 16 girls). Their median age at diagnosis was 3.7 years (range 1-14). Twenty had pre-B ALL and 16 common ALL. Elevated ETP and Peak of TG in ALL patients above the 97,5 percentile of NC were noted at diagnosis and persisted during all the Induction phase. During Interval Therapy and later at start of Maintenance, ETP and Peak returned to values below 97.5 percentile of NC. During Late Intensification, ETP and Peak levels increased above the 97.5 percentile of NC. At all time points studied the variation of ETP and Peak levels were similar in the presence and absence of TM. PC, PS, AT and fibrinogen levels decreased during Induction phase with median PS level remaining within the 2.5-97.5 percentile of NC and median AT and PC levels reaching a value lower than the 2.5 percentile of NC at the time of the 7th and 8th Aase infusion respectively (day 32 and 35). Fibrinogen levels were below the 2.5 percentile of NC during Induction from day 15 to day 29. Among the 36 analyzed patients, 2 experienced 3 symptomatic thromboses. One sub-clavian thrombosis occurred during Induction on day 22 and 1 jugular vein thrombosis occurred in a second child after completion of Induction on day 50 (13 days after the 8thAase infusion). These 2 events were concurrent with a central venous catheter infection. The second patient also developed during Late Intensification a cerebral thrombosis in the longitudinal sinus. Concomitant to these three events, ETP and Peak values of these patients were above the P75 value of ALL patients sampled at the same time points compatible with a marked prothrombotic profile and a higher risk of thrombosis. This study suggests that TG is a promising global assay to evaluate the hypercoagulable state in ALL children under treatment. TG reveals an increased thrombin potential which is present early at diagnosis, persists during Induction and reappears during Late Intensification. This observation is consistent with the high incidence of thrombotic events previously described during Induction and until 10 days after the last Aase infusion. TG profiles observed in patients who experienced thrombotic events suggest that this assay could be used as a predictive tool since their TG parameters were above P75 value of the ALL children tested. Further investigations are needed to address this issue. Disclosures: No relevant conflicts of interest to declare.