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Abstract: Ataxia-telangiectasia (A-T) is an autosomal-recessive disorder caused by pathogenic variants (PVs) of the ATM gene, predisposing children to hematological malignancies. We investigated their characteristics and outcomes to generate data-based treatment recommendations. In this multinational, observational study we report 202 patients aged ≤25 years with A-T and hematological malignancies from 25 countries. Ninety-one patients (45%) presented with mature B-cell lymphomas, 82 (41%) with acute lymphoblastic leukemia/lymphoma, 21 (10%) with Hodgkin lymphoma and 8 (4%) with other hematological malignancies. Four-year overall survival and event-free survival (EFS) were 50.8% (95% confidence interval [CI], 43.6-59.1) and 47.9% (95% CI 40.8-56.2), respectively. Cure rates have not significantly improved over the last four decades (P = .76). The major cause of treatment failure was treatment-related mortality (TRM) with a four-year cumulative incidence of 25.9% (95% CI, 19.5-32.4). Germ line ATM PVs were categorized as null or hypomorphic and patients with available genetic data (n = 110) were classified as having absent (n = 81) or residual (n = 29) ATM kinase activity. Four-year EFS was 39.4% (95% CI, 29-53.3) vs 78.7% (95% CI, 63.7-97.2), (P < .001), and TRM rates were 37.6% (95% CI, 26.4-48.7) vs 4.0% (95% CI, 0-11.8), (P = .017), for those with absent and residual ATM kinase activity, respectively. Absence of ATM kinase activity was independently associated with decreased EFS (HR = 0.362, 95% CI, 0.16-0.82; P = .009) and increased TRM (hazard ratio [HR] = 14.11, 95% CI, 1.36-146.31; P = .029). Patients with A-T and leukemia/lymphoma may benefit from deescalated therapy for patients with absent ATM kinase activity and near-standard therapy regimens for those with residual kinase activity., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Hyperleukocytosis in pediatric acute myeloid leukemia (AML) is associated with severe complications and an inferior outcome. We report results on patients with hyperleukocytosis included in the NOPHO-DBH AML 2012 study. We recommended immediate initiation of full-dose chemotherapy (etoposide monotherapy for 5 days as part of the first course), avoiding leukapheresis and prephase chemotherapy. Of 714 patients included in the NOPHO-DBH AML 2012 study, 122 (17.1%) had hyperleukocytosis, and 111 were treated according to the recommendations with etoposide upfront without preceding leukapheresis or prephase chemotherapy. The first dose was applied the same day as the AML diagnosis or the day after in 94%. Etoposide was administered via peripheral veins in 37% of patients without major complications. After initiation of etoposide the white blood cell counts on days 2-5 were 69%, 36%, 17% and 8%, respectively, of the pre-treatment level. On day 3, 81% of patients had a white blood cell count <100 x109/L. Five-year event-free and overall survival rates for all patients with hyperleukocytosis were 52.9% (95% confidence interval [95% CI]: 44.4-63.0) and 74.1% (95% CI: 66.4-82.6), compared to 64.9% (95% CI: 60.9-69.1) and 78.9% (95% CI: 75.4-82.4) for patients without hyperleukocytosis (P<0.001 for event-free survival, P=0.1 overall survival). Six-week early mortality was 4.1% for all patients with hyperleukocytosis (2.7% for the 111 patients treated with etoposide upfront). We conclude that management of hyperleukocytosis in pediatric AML with immediate etoposide monotherapy without leukapheresis or prephase chemotherapy is feasible, safe and effective. The reduction in white blood cell count during the first days is comparable to the reported results of leukapheresis, and outcomes seem at least equivalent to therapies including leukapheresis. Based on our results, we advocate abandoning leukapheresis for hyperleukocytosis in pediatric AML. Instead, it is crucial to start induction chemotherapy as early as possible.

This case report describes a 2-month-old girl with acute megakaryoblastic leukemia (AMKL) harboring the t(1;22)(p13;q13) translocation, resulting in the RBM15::MRTFA fusion gene. She presented with massive hepatosplenomegaly and liver fibrosis and achieved complete remission with chemotherapy; the liver fibrosis resolved within 2.5 months. After 12 years of follow-up, the patient remained in good health, without relapse. Reviewing the literature on eight additional similar cases of liver fibrosis, this subtype of AMKL predominantly affects female patients below 3 months of age, with a median onset at 6 weeks. High rates of severe complications were observed, with five of nine patients dying within 10 weeks of diagnosis. The authors hypothesized that the proliferation of abnormal megakaryoblasts within the liver leads to the release of profibrotic cytokines, such as TGF-β1, which induces liver fibrosis similar to that observed in transient abnormal myelopoiesis in Down syndrome. Careful monitoring of liver functions and reduced-intensity chemotherapy are recommended for this very young patient population. Nonetheless, long-term survival can be achieved with aggressive supportive care and treatment., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Arad-Cohen, Attias, Zohar and Messinger.)

Since bacteremia complicates childhood Acute myeloid leukemia (AML) patients, we assessed bacteremia rates in Israeli children with de-novo AML. All chemotherapy courses of patients enrolled in NOPHO-DBH-2012 AML protocol were included. Down syndrome, acute promyelocytic leukemia were excluded. Among 69 patients, seven had focal bacterial infections. Of the remaining 62, 77.4% had 1-8 bacteremias. Of 238 chemotherapy courses, 98 (41.2%) had bacteremia: 66 (67.3%) predominantly Gram-negative rods (GNR); 28 (28.6%) Gram-positive cocci. Escherichia coli ; followed by Klebsiella were most common. Older age, Arab ethnicity, and presenting white blood cell count were associated with an increased risk of bacteremia in the univariable analysis, but these associations were not confirmed in the multivariable analysis. Mortality was high (9.7%), and bacteremia increased PICU utilization 7-fold half from GNR. Most isolates were sensitive to vancomycin/meropenem (94.7%), but GNR had low sensitivity to quinolones (61.8%). High mortality and morbidity of de-novo AML patients from predominantly GNR bacteremia require specific interventions but limited susceptibility to quinolones hampers prophylaxis.

Abstract: A comprehensive international consensus on the cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1256 children with KMT2A-r AML aims to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs) and to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared with our previous study, 3 additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, and 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8%-76.2%; P < .01). ACAs occurred in 46.8% of 1200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P < .01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcomes was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate 5 adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine the risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcomes and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Purpose: Measurable residual disease (MRD) by using flow cytometry after induction therapy is strongly prognostic in pediatric AML, and hematopoietic stem-cell transplant (hSCT) may counteract a poor response. We designed a phase III study with intensified response-guided induction and MRD-based risk stratification and treated poor induction response with hSCT. The efficacy of liposomal daunorubicin (DNX) in induction was compared with mitoxantrone., Methods: The study planned to randomly assign 300 patients, but the production of DNX ceased in 2017. One hundred ninety-four patients were randomly assigned to mitoxantrone or experimental DNX in induction 1. Ninety-three non-randomly assigned patients served as an observation cohort. Primary end point was fraction of patients with MRD <0.1% on day 22 after induction 1. Patients with MRD ≥15% after induction 1 or ≥0.1% after induction 2 or FLT3 -ITD with NPM1 wildtype were stratified to high-risk therapy, including hSCT., Results: Outcome for all 287 children was good with 5-year event-free survival (EFS 5y ) 66.7% (CI, 61.4 to 72.4) and 5-year overall survival (OS 5y ) 79.6% (CI, 75.0 to 84.4). Overall, 75% were stratified to standard-risk and 19% to high-risk. There was no difference in the proportion of patients with MRD <0.1% on day 22 after induction 1 (34% mitoxantrone, etoposide, araC [MEC], 30% DNX, P = .65), but the proportion increased to 61% for MEC versus 47% for DNX ( P = .061) at the last evaluation before induction 2. EFS 5y was significantly lower, 56.6% (CI, 46.7 to 66.5) versus 71.9% (CI, 63.0 to 80.9), and cumulative incidence of relapse (CIR) was higher, 35.1% (CI, 25.7 to 44.7) versus 18.8% (CI, 11.6 to 27.2) for DNX. The inferior outcome for DNX was only in standard-risk patients with EFS 5y 55.3% (CI, 45.1 to 67.7) versus 79.9% (CI, 71.1 to 89.9), CIR 39.5% (CI, 28.4 to 50.3) versus 18.7% (CI, 10.5 to 28.7), and OS 5y 76.2% (CI, 67.2 to 86.4) versus 88.6% (CI, 81.4 to 96.3). As-treated analyses, including the observation cohort, supported these results. For all high-risk patients, 85% received hSCT, and EFS 5y was 77.7 (CI, 67.3 to 89.7) and OS 5y was 83.0 (CI, 73.5 to 93.8)., Conclusion: The intensification of induction therapy with risk stratification on the basis of response to induction and hSCT for high-risk patients led to improved outcomes. Mitoxantrone had a superior anti-leukemic effect than liposomal daunorubicin.

Children with Down syndrome (DS) are at a significantly higher risk of developing acute myeloid leukemia, also termed myeloid leukemia associated with DS (ML-DS). In contrast to the highly favorable prognosis of primary ML-DS, the limited data that are available for children who relapse or who have refractory ML-DS (r/r ML-DS) suggest a dismal prognosis. There are few clinical trials and no standardized treatment approach for this population. We conducted a retrospective analysis of international study groups and pediatric oncology centers and identified 62 patients who received treatment with curative intent for r/r ML-DS between year 2000 to 2021. Median time from diagnosis to relapse was 6.8 (range, 1.1-45.5) months. Three-year event-free survival (EFS) and overall survival (OS) were 20.9 ± 5.3% and 22.1 ± 5.4%, respectively. Survival was associated with receipt of hematopoietic stem cell transplantation (HSCT) (hazard ratio [HR], 0.28), duration of first complete remission (CR1) (HR, 0.31 for > 12 months) and attainment of remission after relapse (HR, 4.03). Patients who achieved complete remission (CR) before HSCT, had an improved OS and EFS of 56.0 ± 11.8% and 50.5 ± 11.9%, respectively compared to those who underwent HSCT without CR (3-year OS and EFS of 10.0 ± 9.5%). Treatment failure after HSCT was predominantly because of disease recurrence (52%) followed by treatment-related mortality (10%). The prognosis of r/r ML-DS remains dismal even in the current treatment period and serve as a reference point for current prognostication and future interventional studies. Clinical trials aimed at improving the survival of patients with r/r ML-DS are needed., (Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: Intensive chemotherapy for acute lymphoblastic leukemia (ALL) may affect the immune system and potentially the immune memory causing antibodies provided by vaccination to disappear. There are disagreements regarding the guidelines for posttreatment immunization strategy., Methods: Ninety-six children (aged 1-18 years at diagnosis) who completed chemotherapy for ALL were recruited. Antibody levels in the patient's serum against measles, varicella, polio, pertussis, hepatitis A, and hepatitis B were tested after completion of chemotherapy in patients who were fully vaccinated against these agents. Children who did not have positive serology to specific agents were revaccinated with a single dose accordingly. Antibody concentrations were measured again at least 4 weeks after revaccination., Results: Positive antibody levels varied between the different agents. The highest percentage of positive serology was against polio (87%) and the lowest against pertussis (4%) (p < .001). There were significant differences between patients with high risk (HR) and non-HR ALL regarding serology status for some vaccines. After revaccination, the levels of response to each booster dose were significantly different: 100% after booster dose for varicella and polio, and only 34% after pertussis booster., Conclusions: Loss of humoral protection for vaccine preventable diseases is a common finding among patients with ALL. Revaccination with one dose of vaccine after completion of chemotherapy achieved seroconversion in 34-100% of the patients depending on the type of vaccine. We recommend this revaccination schedule to all children who completed ALL therapy and were previously fully vaccinated., (© 2023 Wiley Periodicals LLC.)

Purpose: A previous study by the International Berlin-Frankfurt-Münster Study Group (I-BFM-SG) on childhood KMT2A -rearranged ( KMT2A -r) AML demonstrated the prognostic value of the fusion partner. This I-BFM-SG study investigated the value of flow cytometry-based measurable residual disease (flow-MRD) and evaluated the benefit of allogeneic stem-cell transplantation (allo-SCT) in first complete remission (CR1) in this disease., Methods: A total of 1,130 children with KMT2A -r AML, diagnosed between January 2005 and December 2016, were assigned to high-risk (n = 402; 35.6%) or non-high-risk (n = 728; 64.4%) fusion partner-based groups. Flow-MRD levels at both end of induction 1 (EOI1) and 2 (EOI2) were available for 456 patients and were considered negative (<0.1%) or positive (≥0.1%). End points were 5-year event-free survival (EFS), cumulative incidence of relapse (CIR), and overall survival (OS)., Results: The high-risk group had inferior EFS (30.3% high risk v 54.0% non-high risk; P < .0001), CIR (59.7% v 35.2%; P < .0001), and OS (49.2% v 70.5%; P < .0001). EOI2 MRD negativity was associated with superior EFS (n = 413; 47.6% MRD negativity v n = 43; 16.3% MRD positivity; P < .0001) and OS (n = 413; 66.0% v n = 43; 27.9%; P < .0001), and showed a trend toward lower CIR (n = 392; 46.1% v n = 26; 65.4%; P = .016). Similar results were obtained for patients with EOI2 MRD negativity within both risk groups, except that within the non-high-risk group, CIR was comparable with that of patients with EOI2 MRD positivity. Allo-SCT in CR1 only reduced CIR (hazard ratio, 0.5 [95% CI, 0.4 to 0.8]; P = .00096) within the high-risk group but did not improve OS. In multivariable analyses, EOI2 MRD positivity and high-risk group were independently associated with inferior EFS, CIR, and OS., Conclusion: EOI2 flow-MRD is an independent prognostic factor and should be included as risk stratification factor in childhood KMT2A -r AML. Treatment approaches other than allo-SCT in CR1 are needed to improve prognosis.

Introduction: Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood, arising from the bone marrow. ALL may present at diagnosis or relapse at extramedullary sites. In recent years, autologous T-cells engineered to express a chimeric-antigen receptor (CAR-T cells) have emerged as novel immune-based therapies for relapsed and refractory ALL, targeting the B-cell surface antigen CD19. Here we present a patient with relapsed ALL involving the ovaries, treated with CD19 CAR-T cells. Toxicity included cytokine-release syndrome and neurotoxicity. CAR-T cell therapy led to a complete remission, with evidence of CAR-T cell trafficking to disease sites including the bone marrow and ovaries.

Introduction: Pediatric acute myeloid leukemia (AML) is the second most common type of pediatric leukemia. Patients with AML are at high risk for several complications such as infections, typhlitis, and acute and long-term cardiotoxicity. Despite this knowledge, there are no definite supportive care guidelines as to what the best approach is to manage or prevent these complications., Area Covered: The NOPHO-DB-SHIP (Nordic-Dutch-Belgian-Spain-Hong-Kong-Israel-Portugal) consortium, in preparation for a new trial in pediatric AML patients, had dedicated meetings for supportive care. In this review, the authors discuss the available data and outline recommendations for the management of children and adolescents with AML with an emphasis on hyperleukocytosis, tumor lysis syndrome, coagulation abnormalities and bleeding, infection, typhlitis, malnutrition, cardiotoxicity, and fertility preservation., Expert Opinion: Improved supportive care has significantly contributed to increased cure rates. Recommendations on supportive care are an essential part of treatment for this highly susceptible population and will further improve their outcome.

As treatments for second relapsed and refractory first relapsed paediatric AML transition from purely palliative to more commonly curative in nature, comparative data is necessary for evaluating the effectiveness of emerging treatment options. Furthermore, little is known about predictors of prognosis following third-line therapy. From 2004 until 2019, 277 of the 869 patients enrolled in NOPHO-DB SHIP consortium trials experienced a first relapse and, of these patients, 98 experienced refractory first relapse and 59 a second relapse. Data on patient and disease characteristics within this cohort of 157 patients was analysed to determine probability of overall survival (pOS) and to identify factors influencing survival. Data on early treatment response and complete remission were not available. One and 5-year pOS were 22 ± 3% and 14 ± 3%, respectively. There was no statistically significant difference in survival between refractory first relapsed and second relapsed AML. Factors influencing prognosis included: late relapse, type of third-line treatment, FLT3 mutational status, and original treatment protocol. These data provide a baseline for evaluating the effectiveness of emerging therapies for the treatment of children with refractory first relapsed and second relapsed paediatric AML and evidence that select patients receiving third-line therapy can be cured., (© 2022 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Invasive Fusarium species infections in immunocompromised patients occur predominantly in those with hematological malignancies. Survival rates of 20−40% were reported in adults, but data in children are limited. Our retrospective, nationwide multicenter study of invasive fusariosis in pediatric hematology/oncology and stem cell transplant (SCT) patients identified twenty-two cases. Underlying conditions included hematological malignancies (n = 16; 73%), solid tumors (n = 2), and non-malignant hematological conditions (n = 4). Nineteen patients (86%) were neutropenic, nine (41%) were SCT recipients, and seven (32%) received corticosteroids. Sixteen patients (73%) had disseminated fusariosis, five had local infection, and one had isolated fungemia. Fifteen patients (68%) had skin involvement and eight (36%) had a bloodstream infection. Four patients (18%) presented with osteoarticular involvement and four with pulmonary involvement. Nineteen patients (86%) received combination antifungal therapy upfront and three (14%) received single-agent treatment. Ninety-day probability of survival was 77%: four of the five deaths were attributed to fusariosis, all in patients with relapsed/refractory acute leukemias. Ninety-day probability of survival for patients with relapsed/refractory underlying malignancy was 33% vs. 94% in others (p < 0.001). Survival rates in this largest pediatric population-based study were strikingly higher than those reported in adults, demonstrating that invasive fusariosis is a life-threatening but salvageable condition in immunosuppressed children.

Background: Osteonecrosis is a major cause of acute and long-lasting complications of acute lymphoblastic leukemia (ALL) therapy in children. Our study aimed to evaluate the prevalence, characteristics, risk factors, and outcome of osteonecrosis in children with ALL., Procedure: The cohort included 559 children aged 1-20 years diagnosed with ALL between 2003 and 2018 at two tertiary medical centers in Israel and enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. Symptomatic osteonecrosis was prospectively captured as an adverse event., Results: Osteonecrosis occurred in 51 patients (9.1%). Ninety-four percent of the events were graded as moderate or severe (grades 3-4, Ponte di Legno Toxicity Working Group classification) and multiple bone involvement was common. Full resolution of osteonecrosis was documented in only 16% of the children (median follow-up 4.2 years). Stepwise logistic regression identified five risk factors for osteonecrosis, with a high predictive value (AUC = 0.88): older ageat ALL diagnosis, high-risk ALL group, T-cell immunophenotype, female gender, and a novel risk factor: bone pain at the time of leukemia diagnosis. In addition, osteonecrosis was less common among children of Arab ethnicity. Thrombophilia and an elevated age-adjusted body mass index were not confirmed as risk factors for osteonecrosis., Conclusion: Due to the low rates of osteonecrosis resolution and its debilitating long-term impact, the identification of patients at high risk for osteonecrosis is important for their inclusion in further studies evaluating potential therapeutic adjustments., (© 2021 Wiley Periodicals LLC.)

Background: Mucormycosis is a life-threatening infection with a tendency for angioinvasion that may lead to progressive dissemination. Disseminated mucormycosis, defined as the involvement of two or more non-contiguous sites, is rare in children, and data concerning its management and outcome are scarce. The aim of this study was to assess the contemporary management strategies and outcomes of disseminated mucormycosis in the pediatric population., Methods: We conducted a retrospective search in six large tertiary medical centers for all cases of disseminated mucormycosis that occurred between 2009-2020 in patients aged 1-20 years., Results: Twelve cases were identified. Underlying conditions included hematological malignancies ( n = 10), solid tumor (post-autologous hematopoietic stem cell transplantations; n = 1), and solid organ (liver) transplantation ( n = 1). In all cases, amphotericin B formulations were administered as first-line therapy; in eight cases, they were also administered in combination with an echinocandin or triazole. Seven patients underwent surgical debridement procedures. The six-week mortality was 58%. Among the patients diagnosed between 2009-2015, one of the six survived, and of those diagnosed between 2016-2020, four of the six were salvaged., Conclusions: Disseminated mucormycosis is a life-threatening and often fatal disease, and improved diagnostic and therapeutic strategies are needed. Nevertheless, in this population-based study, five patients (42%) were salvaged through combined liposomal amphotericin/triazole treatment and extensive surgical interventions.

Venous thromboembolism (VTE) is a serious complication of acute lymphoblastic leukemia (ALL) therapy. The aim of this population-based study was to evaluate the rate, risk factors, and long-term sequelae of VTE in children treated for ALL. The cohort included 1191 children aged 1-19 years diagnosed with ALL between 2003-2018, prospectively enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. VTEs occurred in 89 patients (7.5%). Long-term sequelae were uncommon. By univariate analysis, we identified four significant risk factors for VTEs: Severe hypertriglyceridemia ( p = 0.005), inherited thrombophilia ( p < 0.001), age >10 years ( p = 0.015), and high-risk ALL group ( p = 0.039). In addition, the incidence of VTE was significantly higher in patients enrolled in AIEOP-BFM ALL 2009 than in those enrolled in ALL-IC BFM 2002 ( p = 0.001). Severe VTE occurred in 24 children (2%), all of whom had at least one risk factor. Elevated triglyceride levels at diagnosis did not predict hypertriglyceridemia during therapy. In a multivariate analysis of 388 children, severe hypertriglyceridemia and inherited thrombophilia were independent risk factors for VTE. Routine evaluation for these risk factors in children treated for ALL may help identify candidates for intervention.

ABL-class fusions other than BCR-ABL1 characterize around 2-3% of precursor B-cell acute lymphoblastic leukemia. Case series indicated that patients suffering from these subtypes have a dismal outcome and may benefit from the introduction of tyrosine kinase inhibitors. We analyzed clinical characteristics and outcome of 46 ABL-class fusion positive cases other than BCR-ABL1 treated according to AIEOP-BFM (Associazione Italiana di Ematologia-Oncologia Pediatrica-Berlin-Frankfurt-Münster) ALL 2000 and 2009 protocols; 13 of them received a tyrosine kinase inhibitor (TKI) during different phases of treatment. ABL-class fusion positive cases had a poor early treatment response: minimal residual disease levels of ≥5×10 -4 were observed in 71.4% of patients after induction treatment and in 51.2% after consolidation phase. For the entire cohort of 46 cases, the 5-year probability of event-free survival was 49.1+8.9% and that of overall survival 69.6+7.8%; the cumulative incidence of relapse was 25.6+8.2% and treatment-related mortality (TRM) 20.8+6.8%. One out of 13 cases with TKI added to chemotherapy relapsed while eight of 33 cases without TKI treatment suffered from relapse, including six in 17 patients who had not received hematopoietic stem cell transplantation. Stem cell transplantation seems to be effective in preventing relapses (only three relapses in 25 patients), but was associated with a very high TRM (6 patients). These data indicate a major need for an early identification of ABL-class fusion positive acute lymphoblastic leukemia cases and to establish a properly designed, controlled study aimed at investigating the use of TKI, the appropriate chemotherapy backbone and the role of hematopoietic stem cell transplantation. (Registered at: clinicaltrials.gov identifier: NTC00430118, NCT00613457, NCT01117441) ., (Copyright© 2020 Ferrata Storti Foundation.)

Mucormycosis has emerged as an increasingly important cause of morbidity and mortality in immunocompromised patients, but contemporary data in children are lacking. We conducted a nationwide multicentre study to investigate the characteristics of mucormycosis in children with haematological malignancies. The cohort included 39 children with mucormycosis: 25 of 1136 children (incidence 2·2%) with acute leukaemias prospectively enrolled in a centralized clinical registry in 2004-2017, and an additional 14 children with haematological malignancies identified by retrospective search of the databases of seven paediatric haematology centres. Ninety-two percent of mucormycosis cases occurred in patients with acute leukaemias. Mucormycosis was significantly associated with high-risk acute lymphoblastic leukaemia (OR 3·75; 95% CI 1·51-9·37; P = 0·004) and with increasing age (OR 3·58; 95% CI 1·24-9·77; P = 0·01). Fifteen patients (38%) died of mucormycosis. Rhinocerebral pattern was independently associated with improved 12-week survival (OR 9·43; 95% CI 1·47-60·66; P = 0·02) and relapsed underlying malignancy was associated with increased 12-week mortality (OR 6·42; 95% CI, 1·01-40·94; P = 0·05). In patients receiving frontline therapy for their malignancy (n = 24), one-year cumulative mucormycosis-related mortality was 21 ± 8% and five-year overall survival was 70 ± 8%. This largest paediatric population-based study of mucormycosis demonstrates that children receiving frontline therapy for their haematological malignancy are often salvageable., (© 2019 British Society for Haematology and John Wiley & Sons Ltd.)

Introduction : Pediatric patients treated for acute myeloid leukemia (AML) are at high risk of developing severe infectious complications. The choice of an optimum supportive treatment should be based on local epidemiology, as well as intensity and toxicity of the anti-leukemic therapy applied. Areas covered : This review presents an overview of recently published studies focusing on the prevention of infection in pediatric AML patients. PubMed has been systematically searched for clinical trials, reviews, and meta-analyses published in the last 10 years. The focus of this article will be limited to primary prophylaxis only, while secondary prophylaxis is beyond the scope of the current review. Expert opinion : Although anti-bacterial agents may decrease the bacterial infection burden, there is no consensus regarding prophylactic use. To that end, there is a need for further randomized controlled trials to establish the precise role of anti-bacterial prophylaxis in pediatric AML patients. The prophylactic use of anti-fungal agents is strongly recommended for all AML patients. Since the contribution of hematopoietic growth factors to improved survival has not been demonstrated, they should not be routinely applied. Decisions regarding an appropriate prophylactic strategy should be taken in collaboration with the infectious disease experts and pharmacology team.

Tremendous progress in the therapy of pediatric acute lymphoblastic leukemia (ALL) has been achieved through combination cytotoxic chemotherapy, leading to high cure rates, at the cost of significant life-threatening toxicity. The bispecific T-cell engager blinatumomab, recently approved for relapsed/refractory ALL, has a unique nonmyelotoxic toxicity profile. As blinatumomab causes B-cell depletion, the safety of its use during severe chemotherapy-induced toxicity is unclear. We report 11 pediatric patients with ALL, treated with blinatumomab following overwhelming chemotherapy-associated toxicity, with recovery of all patients and successful bridging to further antileukemia therapy. Blinatumomab can be considered for rare patients who cannot tolerate cytotoxic therapy., (© 2019 Wiley Periodicals, Inc.)

This study investigated the prevalence of inherited thrombophilia, risk of venous thromboembolism (VTE) and benefit of low molecular weight heparin prophylaxis in 476 Israeli children with acute lymphoblastic leukaemia (ALL) treated between 2004 and 2016. Thrombophilia was found in 15·5%. Arab children had a higher prevalence of F5 R506Q (factor V Leiden) than Jewish children (19·4% vs. 2·9%, P < 0·01). Patients with thrombophilia had higher VTE rates VTE (26·5% vs. 5·6%, P < 0·001). None of the thrombophilic children given prophylaxis had severe VTE. Routine evaluation for inherited thrombophilia followed by thromboprophylaxis when findings are positive may benefit at-risk patients with ALL., (© 2019 British Society for Haematology and John Wiley & Sons Ltd.)

To study the prognostic relevance of rare genetic aberrations in acute myeloid leukemia (AML), such as t(16;21), international collaboration is required. Two different types of t(16;21) translocations can be distinguished: t(16;21)(p11;q22), resulting in the FUS-ERG fusion gene; and t(16;21)(q24;q22), resulting in RUNX1-core binding factor ( CBFA2T3 ). We collected data on clinical and biological characteristics of 54 pediatric AML cases with t(16;21) rearrangements from 14 international collaborative study groups participating in the international Berlin-Frankfurt-Münster (I-BFM) AML study group. The AML-BFM cohort diagnosed between 1997 and 2013 was used as a reference cohort. RUNX1-CBFA2T3 (n = 23) had significantly lower median white blood cell count (12.5 × 10 9 /L, P = .03) compared with the reference cohort. FUS-ERG rearranged AML (n = 31) had no predominant French-American-British (FAB) type, whereas 76% of RUNX1-CBFA2T3 had an M1/M2 FAB type (M1, M2), significantly different from the reference cohort ( P = .004). Four-year event-free survival (EFS) of patients with FUS-ERG was 7% (standard error [SE] = 5%), significantly lower compared with the reference cohort (51%, SE = 1%, P < .001). Four-year EFS of RUNX1-CBFA2T3 was 77% (SE = 8%, P = .06), significantly higher compared with the reference cohort. Cumulative incidence of relapse was 74% (SE = 8%) in FUS-ERG , 0% (SE = 0%) in RUNX1-CBFA2T3, compared with 32% (SE = 1%) in the reference cohort ( P < .001). Multivariate analysis identified both FUS-ERG and RUNX1-CBFA2T3 as independent risk factors with hazard ratios of 1.9 ( P < .0001) and 0.3 ( P = .025), respectively. These results describe 2 clinically relevant distinct subtypes of pediatric AML. Similarly to other core-binding factor AMLs, patients with RUNX1-CBFA2T3 rearranged AML may benefit from stratification in the standard risk treatment, whereas patients with FUS-ERG rearranged AML should be considered high-risk., (© 2018 by The American Society of Hematology.)

Background: Immunocompromised children are at high risk of rapid deterioration and of developing life-threatening pulmonary infections. Etiologies in this setting are diverse, including those that are infectious and noninfectious, and many etiologies may coexist. Accurate diagnosis is required for the rational use of medications. Fiberoptic bronchoscopy (FOB) with bronchoalveolar lavage (BAL) can identify infectious causes in this population., Objectives: The aims of this study were to evaluate diagnostic rate, safety, and changes in treatment following FOB with BAL, when applied with advanced laboratory diagnostic techniques., Patients and Methods: We reviewed the records of children who underwent FOB with BAL during the period spanning from 2006 to 2014 in the Hematology-Oncology Department. BAL samples were processed in microbiology, virology, cytology, and molecular laboratories., Results: Antimicrobials were initiated in 91 of 117 children. BAL yielded an infectious etiology in 55 episodes. Management was altered in 74 patients following a positive (40/55) or a negative (30/54) result (4 patients had missing data). No severe complications associated with the procedures occurred., Conclusions: Most immunocompromised patients with pulmonary manifestations are treated empirically with multiple medications. Evaluation FOB/BAL is a useful diagnostic tool, and seems to have changed the course of therapy in more than half of patients, by initiation or cessation of treatment. FOB/BAL is a safe diagnostic tool for the evaluation of pulmonary manifestations in this setting.

Nontuberculous mycobacteria may cause central venous catheter-associated bacteremia. Between March 2011 and October 2013, 6 cases of Mycobacterium phocaicum bacteremia were found in the pediatric hematology-oncology department. All patients recovered. No positive blood culture was documented after removal of the central venous catheter. All 4 patients with pulsed field gel electrophoresis had the same pattern, different from the water sample, suggesting a common water source.

Introduction: Traditionally in pediatric oncology, biopsies were incisional, with a recent alternative of percutaneous imaging-guided biopsies. In our department, ultrasound (US)-guided core biopsy is the first choice for tissue diagnosis in the pediatric population. We retrospectively reviewed our experience and assessed the accuracy rate, safety, and availability of the procedure., Materials and Methods: Pediatric US-guided biopsies performed in our hospital between November 2003 and November 2011 were studied. Data collection included demographics, clinical and procedural data, and follow-up., Results: A total of 213 biopsies were performed on 191 patients: 40 known oncologic patients and 173 to establish diagnosis. Seventeen biopsies were excluded, as malignancy was not suspected. Sixty-five percent of the patients had a biopsy within a day. A total of 138 biopsies with tumor at the biopsy site were correctly diagnosed and 4 were missed. Fifty-eight patients were negative for tumor. The sensitivity of our ultrasound-guided core biopsy is 97.1%, specificity 100%, and accuracy 97.9%.We found no complication related to sedation, and 2 procedural complications-bleeding from the biopsy site and seeding of tumor cells-were reported., Discussion: We find US-guided core biopsy for suspected malignancy in the pediatric population to be highly available, safe, and very accurate, having a potential to become the procedure of choice.

Background: Immunocompromised patients are at increased risk for severe respiratory syncytial virus (RSV) infection. Palivizumab is approved for prevention of RSV in specific populations but not for treatment. Few studies demonstrated the safety and successful treatment with intravenous (IV) palivizumab. We describe our experience with IV palivizumab treatment for RSV in a pediatric hematology-oncology department during an outbreak., Methods: During a short period of renovations, oncology patients were placed in a general pediatric ward. After a case of severe fatal RSV pneumonia in a 2-year-old male patient with acute myeloid leukemia, all patients were actively screened twice weekly regardless of symptoms. Respiratory samples were tested for RSV using rapid immunochromatography detection, immunofluorescence, or reverse transcriptase polymerase chain reaction. A single dose of palivizumab (15 mg/kg) was given to children below 3 years of age who tested positive for RSV., Results: Over a 6-week period, 12 patients tested positive for RSV. Seven patients were treated with palivizumab. Five patients had respiratory symptoms, and 2 were asymptomatic. No adverse events were attributed to IV palivizumab treatment. Early-treated patients had no complications attributed to RSV., Conclusions: Containment of RSV outbreak in high-risk children is difficult. Screening with reverse transcriptase polymerase chain reaction and the early use of IV palivizumab is safe and may prevent complications of RSV infection among these patients.

Legionnaires' disease is a rare cause of community acquired pneumonia in children and is exceedingly rare in infants and neonates. We describe a case of a 15 years old female, with lymphoblastic leukemia and legionella pneumophila pneumonia. Diagnosis was made by specific culture and polymerase chain reaction method from sputum and bronchoalveolar ravage specimens. Treatment was prolonged because of slow resolution and the fact that she underwent bone marrow transplantation. This emphasizes the importance of considering this rare entity in cases of severe pneumonia, especially in the immunocompromised host.

Objective: To determine the prevalence and relationship between apnea and gastroesophageal reflux (GER) among infants with apparent life-threatening events., Methods: We evaluated 67 infants of ages up to 6 months who had an idiopathic apparent life-threatening event as determined by polysomnography and pH monitoring., Results: No reflux (pH < 4 for more than 6 seconds) was evident in 32 infants. Fourteen others had such prolonged reflux that the relationship between apnea and reflux could not be evaluated. The 21 remaining infants who had episodes of apnea and reflux constituted the study group. In 81% of the apneic episodes, no relationship to GER was noted. Apnea preceded reflux in 93.6% of the episodes, and only 6.4% of the apneic episodes followed reflux. When apnea preceded reflux, the apnea was obstructive in 66.8% of episodes and mixed in 33.2%. Central apnea was not recorded preceding reflux., Conclusions: Episodes of apnea were seldom associated with GER. However, in those instances when apnea and reflux were associated, the predominant sequence of events was obstructive apnea and to a lesser extent mixed apnea followed by reflux.