Abstract Introduction The time elapsed from diagnosis to hematopoietic stem cell transplantation (HSCT) is influenced by numerous factors. In Brazil, patients using the public health system are also dependent on the availability of HSCT-specific beds in the hematology ward. Objective and Methods We conducted a cohort study of listed patients who underwent allogeneic HSCT at a Brazilian public hospital to investigate the impact of the waitlist time on post-HSCT survival. Results The median time from diagnosis to HSCT was 19 months (IQR, 10 - 43), of which 6 months (IQR, 3 - 9) were spent on the waitlist. The time on the waitlist for HSCT appeared to influence mainly the survival of adult patients (≥ 18 years), with an increasing risk according to this time (RR, 3.53 and 95%CI, 1.81 - 6.88 for > 3 and ≤ 6 months; RR 5.86 and 95%CI, 3.26 - 10.53 for > 6 and ≤ 12 months, and; RR 4.24 and 95%CI, 2.32 - 7.75 for > 12 months). Conclusion Patients who remained on the waitlist for less than 3 months had the highest survival (median survival, 856 days; IQR, 131 - 1607). The risk of reduced survival was about 6-fold higher (95%CI, 2.8 - 11.5) in patients with malignancies. (HSCT factors Brazil HSCTspecific specific ward postHSCT post 1 IQR (IQR 43, 43 , 43) 9 ≥ ( years, years years) RR, (RR 353 53 3.5 95CI CI 95 95%CI 181 81 1.8 688 88 6.8 586 5 86 5.8 326 26 3.2 1053 10.5 424 4 24 4.2 232 2 32 2.3 775 7 75 7.7 months. . months) 85 days 13 1607. 1607 1607) 6fold fold (95%CI 28 8 2. 11.5 115 11 malignancies 35 3. 1. 68 6. 58 5. 105 10. 42 4. 23 77 7. 160 11. 16

ABSTRACT Introduction: The treatment of acute lymphoblastic leukemia (ALL) has evolved in recent decades, reaching an overall survival rate close to 90%. Currently, approximately 4% of patients with ALL die from secondary complications of chemotherapy. Among these complications, the most frequent is febrile neutropenia (FN). The treatment of acute myeloid leukemias (AMLs) is even more aggressive, being consequently related to a considerable amount of treatment-related toxicity with a high risk of severe infection and death. Method: In order to reduce the infection-related risks in these groups of patients, systemic antibacterial prophylaxis has emerged as a possible approach. Results: Antibiotic prophylaxis during neutropenia periods in those undergoing chemotherapy have .already been proven in adults with acute leukemias (ALs). Among the possible available therapeutic options for bacterial prophylaxis in children with cancer, fluoroquinolones emerged with the most amount of evidence. Within this class, levofloxacin became the best choice. Conclusion: Therefore, the use of levofloxacin seems to be indicated in very specific situations: in children who are known to be neutropenic for a long time, secondary to intensive chemotherapy; in children with AL undergoing chemotherapy to induce remission; or in children undergoing hematopoietic stem cell transplantation (HSCT). This article aims to describe recent evidence focusing on antibiotic prophylaxis in children with ALs. Introduction (ALL decades 90 90% Currently 4 FN. FN . (FN) AMLs (AMLs aggressive treatmentrelated death Method infectionrelated approach Results already ALs (ALs) cancer class choice Conclusion Therefore situations time remission HSCT. HSCT (HSCT) 9 (FN (ALs (HSCT

ABSTRACT Background: Despite high cure rates, treatment-related mortality in children with acute lymphoblastic leukemia (ALL) remains significant. About 4% of patients die during remission induction therapy and approximately two-thirds of treatment-related deaths are due to infectious complications. Methods: From May 2021 to June 2022, children aged one through 18 years, with a recent diagnosis of ALL, admitted to three pediatric oncology centers in Brazil, were enrolled in this multicenter, open-label, randomized, phase 3 clinical trial. Eligible patients were randomly divided into two groups, based on a 1:1 allocation ratio, to receive, or not, levofloxacin as a prophylactic agent during the induction phase. All patients were treated according to the IC-BFM 2009 chemotherapy protocol. Primary endpoints were carbapenemase-producing Enterobacteriaceae (CPE) colonization, Clostridioides difficile diarrhea, and other adverse events related to the use of levofloxacin. The secondary endpoint was febrile neutropenia during induction. The median follow-up was 289 days. Results: Twenty patients were included in this trial, 10 in each group (control and levofloxacin). Mild adverse reactions related to levofloxacin were observed in three patients (30%). Three patients had Clostridioides difficile diarrhea, two in the levofloxacin group and one in the control group (p > 0.99). Only one patient presented colonization by CPE. This patient belonged to the levofloxacin group (p > 0.99). Nine patients presented febrile neutropenia, five in the control group and four in the levofloxacin intervention group (p > 0.99), one patient died due to febrile neutropenia. Conclusion: The use of levofloxacin was shown to be safe in the induction phase in children with de novo ALL. The use of this medication did not increase the rate of colonization by CPE nor the rate of diarrhea by C. difficile. All adverse reactions were mild and remitted either spontaneously or after switching medicine administration from oral to intravenous route. Background rates treatmentrelated treatment ALL (ALL significant 4 twothirds thirds complications Methods 202 2022 1 years Brazil multicenter openlabel, openlabel open label, label open-label randomized trial groups 11 1: ratio receive ICBFM IC BFM 200 protocol carbapenemaseproducing carbapenemase producing (CPE followup follow up 28 days Results . levofloxacin) 30%. 30 30% (30%) p 0.99. 099 0.99 0 99 0.99) 0.99, , Conclusion C route 20 2 (30% 09 0.9 9 (30 0. (3 (

Abstract: The aim of the present study was to analyze the relationship of OM with possible risk factors such as oral health condition, immunological status and IL-1β profile in patients submitted to hematopoietic stem cell transplantation (HSCT). Fifty-four individuals submitted to HSCT were included. All patients received previous dental treatment and photobiomodulation (PBM) as the institutional OM preventive protocol. OM scores, immune status, and IL-1β levels were determined during the conditioning period and at D+3 and D+8 after HSC infusion. IL-1β gene polymorphism was also analyzed during conditioning. Possible associations of OM with risk factors were analyzed using conditional Fisher's exact test. OM was observed in 34 patients (62.9%) classified as Grade 1 (13 patients/24.1%), Grade 2 (14 patients/25.9%), Grade 3 (3 patients/5.5%), and Grade 4 (4 patients/7.4%). Allogeneic HSCT individuals exhibited a higher OM grade than autologous subjects. Moreover, an association was observed between severe OM and severe gingivitis (p = 0.01), neutropenia (p = 0.03), and leukopenia (p = 0.04). A significant association between OM and lower IL-1β levels was detected at three time points, i.e., conditioning (p = 0.048), D+3 (p = 0.01), and D+8 (p = 0.005). The results showed that IL-1β gene polymorphism was not associated with OM. Our study provided important insights into the scope of OM risk factors in the setting of HSCT. Patients submitted to HSCT with severe gingivitis prior to chemotherapy and with severe neutropenia and leukopenia exhibited a higher OM grade. Further investigation will be necessary to better understand the exact role of IL-1β in the context of OM pathobiology and to validate cytokine analysis in larger cohorts.

Abstract This work aimed to better understand the impact of pandemics of respiratory viruses on children with hemoglobinopathies through a comprehensive review of the literature. MEDLINE, SCIELO, LILACS, and PUBMED were used as data sources to find articles without time period restrictions. Previous observations suggest that patients with hemoglobinopathies are a group especially susceptible to the complications of viral respiratory infections, with greater morbidity and mortality related to them. Within this context, this review found that, during the 2009 H1N1 pandemic, the risk of hospitalization in children and adults increased, especially in patients with a history of complications such as acute chest syndrome. In addition, the Coronavirus Disease 2019 (COVID-19) pandemic appears to have less repercussion among children with hemoglobinopathies compared to adults, similar to what is seen in the general population. In the H1N1 pandemic, patients with hemoglobinopathies behaved as a group more susceptible to complications, with increased morbidity and mortality. However, for COVID-19, the existing data to date on these patients do not show the same clinical impact. Thus, although these children deserve attention in case of infection due to their potential risks, they seem to have a favorable evolution. Highlights Children with hemoglobinopathies have less severe conditions with Coronavirus 2019 Disease (COVID-19) compared to adults, which is similar to that observed in the general population In the H1N1 pandemic, patients with hemoglobinopathies behaved as the group most susceptible to complications, with increased morbidity and mortality

Abstract Objective: This study aims to describe the epidemiological characteristics and survival rates of children with acute myeloid leukemia treated in hospitals in southern Brazil and compare them with international data. Methods: A multicenter cohort study was conducted with retrospective data collection of all new patients with acute myeloid leukemia under 18 treated at five referral centers in pediatric hematology-oncology in southern Brazil between January 2005 and December 2015. Results: Of the 149 patients with acute myeloid leukemia, 63.0% (n = 94) were male. The median age at diagnosis was 10.5 years (range 0–18 years) and 40.3% (n = 60) had a white blood cell count below 50,000/mm2. The most common Franco-American-British (FAB) subtype was M3 (n = 43, 28.9%). Nine (6.0%) patients had central nervous system disease. In M3 patients, overall survival (OS) was 69.2% and 3-year event-free survival was 67.7%; in non-M3 patients, these rates were 45.3% and 36.7%, respectively. In non-M3 patients, OS was significantly different between transplanted (61.8%) and non-transplanted (38.2%) patients (p = 0.031). Conclusions: These results show a higher prevalence of the Franco-American-British M3 subtype than that reported in the international literature, as well as a decreased OS compared with that of developed countries. Further multicenter Brazilian studies with a larger sample size are encouraged to better understand the characteristics of acute myeloid leukemia, and to improve the treatment and prognosis in this population.

ABSTRACT Introduction: To assess the frequency of allergic reactions to asparaginase (ASP) and possible risk factors for reactions in a cohort of pediatric patients. Method: The study was performed based on retrospective data from patients under acute lymphoid leukemia treatment in a general university hospital located in southern Brazil. Information on patients who used ASP from 2010 to 2017 was collected. Allergic reactions were identified in electronic medical records. Results: Among the 98 patients included in the study, 16 (16.3 %) experienced an allergic reaction to native l-asparaginase (L-ASP). Of the 22 patients (22.4 %) that received only intravenous (IV) administration of l-ASP, 10 (62.5 %) had allergic reactions, while 48 patients (49 %) received intramuscular (IM) administration and 28 (28.6 %) received IV and IM administrations. The occurrence of allergic reactions differed between the groups (p < 0.001), and IV administration was associated with allergic reactions. Association was also observed between the severity of the reaction and the route of administration, with the IM route associated with grade 2 and IV route associated with grade 3. Occurrence of allergic reactions was higher when the commercial formulation of l-ASP, Leuginase®, was used (p = 0.0009 in the analysis per patient and p = 0.0003 in the analysis per administration). Conclusions: The IV administration and commercial Leuginase® presentation were associated with more allergic reactions in the study population, which corroborates the findings in the literature. The IV route was also associated with higher severity of reactions in the present study.

RESUMO Objetivo: Descrever um caso de um paciente pediátrico que apresentou linfo-histiocitose hemofagocítica (LHH) associada à leucemia monocítica aguda pós-quimioterapia, com hemofagocitose causada pelas próprias células leucêmicas. Descrição do caso: Em um hospital universitário do Sul do Brasil, uma menina de três anos foi diagnosticada com leucemia monocítica aguda com cariótipo normal. Após receber protocolo quimioterápico, atingiu remissão seis meses depois do início do tratamento, recaíndo quatro meses após com um cariótipo complexo envolvendo ambos os cromossomos, 8p e 16q. A medula óssea mostrava-se infiltrada por células blásticas vacuolizadas com aspecto monocítico, com evidências de hemofagocitose. A criança apresentou um declínio clínico progressivo e dois meses após a recaída foi a óbito. Comentários: A LHH é uma condição inflamatória rara e agressiva caracterizada por citopenias, hepatoesplenomegalia, febre e hemofagocitose na medula óssea, linfonodos, baço e fígado. A LHH associada a doenças malignas, embora seja uma condição rara, é potencialmente fatal. A paciente deste caso apresentou cinco dos oito critérios estabelecidos para o diagnóstico de LHH. A evolução do cariótipo do paciente, independentemente do perfil do diagnóstico, pareceu ser secundária ao tratamento da leucemia monocítica aguda, sendo que a instabilidade citogenética pode ter influenciado o comportamento atípico observado nas células leucêmicas. Este é um dos raros casos de LHH em uma criança com leucemia monocítica aguda.

ABSTRACT Objective: To describe the case of a child who presented hemophagocytic lymphohistiocytosis (HLH) associated with acute monocytic leukemia after chemotherapy, with hemophagocytosis caused by leukemic cells. Case description: In a university hospital in Southern Brazil, a 3-year-old female was diagnosed with acute monocytic leukemia with normal karyotype. The chemotherapy regimen was initiated, and she achieved complete remission six months later, relapsing after four months with a complex karyotype involving chromosomes 8p and 16q. The bone marrow showed vacuolated blasts with a monocytic aspect and evidence of hemophagocytosis. The child presented progressive clinical deterioration and died two months after the relapse. Comments: HLH is a rare and aggressive inflammatory condition characterized by cytopenias, hepatosplenomegaly, fever, and hemophagocytosis in the bone marrow, lymph nodes, spleen, and liver. Although rare, malignancy-associated HLH (M-HLH) is fatal. The patient in this case report met five out of the eight established criteria for HLH. The evolution of the patient’s karyotype, regardless of the diagnostic profile, seemed secondary to the treatment for acute monocytic leukemia. In this case, the cytogenetic instability might have influenced the abnormal behavior of leukemic cells. This is a rare case of HLH in a child with acute monocytic leukemia.

ABSTRACT Background: The minimal residual disease (MRD) is the most important prognostic factor for acute lymphoblastic leukemia (ALL) in children. This study aimed to investigate the influence of detecting the MRD by the multiparametric flow cytometry (MFC) at day 15 (D15) of the induction on the analysis of the risk group classifications of the different childhood ALL treatment protocols used in a referral hospital in southern Brazil. Method: We retrospectively reviewed the medical records of patients with B-cell ALL, aged 1 to 18 years, treated at a hospital from January 2013 to April 2017. Main results: Seventy-five patients were analyzed. Regarding the MRD by the MFC at D15, the analyses showed statistical significance when the MRD was grouped into three categories, < 0.1%, 0.1–10%, and > 10%, with the following distribution: 30.7%, 52.0%, and 17.3%, respectively. There was a significant association between D15 MRD-MFC < 0.1% and the likelihood of dying or relapsing and between D15 MRD-MFC > 10% and the likelihood of dying or relapsing. The cumulative hazard ratio for the relapse of patients with D15 MRD-MFC < 0.1%, 0.1–10%, and > 10% was 19.2%, 59.8%, and 80.1%, respectively. Conclusion: Our analysis suggests D15 MRD-MFC < 0.1% as a cut-off point for patients with more favorable outcomes and that the MRD at D15 in risk classifications is particularly useful for the stratification of patients with a more favorable prognosis.

ABSTRACT The long-term outcome of acute lymphoblastic leukemia has improved dramatically due to the development of more effective treatment strategies. L-asparaginase (ASNase) is one of the main drugs used and causes death of leukemic cells by systematically depleting the non-essential amino acid asparagine. Three main types of ASNase have been used so far: native ASNase derived from Escherichia coli, an enzyme isolated from Erwinia chrysanthemi and a pegylated form of the native E. coli ASNase, the ASNase PEG. Hypersensitivity reactions are the main complication related to this drug. Although clinical allergies may be important, a major concern is that antibodies produced in response to ASNase may cause rapid inactivation of ASNase, leading to a worse prognosis. This reaction is commonly referred to as "silent hypersensitivity" or "silent inactivation". We are able to analyze hypersensitivity and inactivation processes by the measurement of the ASNase activity. The ability to individualize the ASNase therapy in patients, adjusting the dose or switching patients with silent inactivation to an alternate ASNase preparation may help improve outcomes in those patients. This review article aims to describe the pathophysiology of the inactivation process, how to diagnose it and finally how to manage it.

ABSTRACT In the present paper we summarize the suggestions of a multidisciplinary group including experts in pediatric oncology and infectious diseases who reviewed the medical literature to elaborate a consensus document (CD) for the diagnosis and clinical management of invasive fungal diseases (IFDs) in children with hematologic cancer and those who underwent hematopoietic stem-cell transplantation. All major multicenter studies designed to characterize the epidemiology of IFDs in children with cancer, as well as all randomized clinical trials addressing empirical and targeted antifungal therapy were reviewed. In the absence of randomized clinical trials, the best evidence available to support the recommendations were selected. Algorithms for early diagnosis and best clinical management of IFDs are also presented. This document summarizes practical recommendations that will certainly help pediatricians to best treat their patients suffering of invasive fungal diseases.

ABSTRACT Objective: To assess clinical outcomes of intolerant, relapsed or refractory patients who could not be treated with new tyrosine kinase inhibitors or experimental therapies. Methods: A retrospective cohort of 90 chronic myeloid leukemia patients in all phases of the disease treated with imatinib mesylate as their first TKI therapy, and with dasatinib or nilotinib as the next line of therapy. We evaluated clinical outcomes of these patients, with special focus on the group that needed more than two therapy lines. Results: Thirty-nine percent of patients were refractory or intolerant to imatinib. An 8-year overall survival rate of the patients who went through three or more lines of treatment was significantly lower, compared to those who were able to maintain imatinib as their first-line therapy (83% and 22%, respectively p < 0.01). Decreased overall survival was associated with advanced-phase disease (p < 0.01), failure to achieve major molecular response in first-line treatment (p < 0.01) and interruption of first-line treatment due to any reason (p = 0.023). Failure in achieving complete cytogenetic response and major molecular response and treatment interruption were associated with the progression to the third-line treatment. Conclusion: The critical outcome observed in relapsed, intolerant or refractory chronic phase CML patients reflects the unmet need for this group of patients without an alternative therapy, such as new drugs or experimental therapies in clinical trials. Broader access to newer treatment possibilities is a crucial asset to improve survival among CML patients, especially those refractory or intolerant to first-line therapies.

ABSTRACT Background: Early recognition of infectious processes in neutropenic patients is hampered by the fact that these processes may have dissimilar and non-specific clinical presentations. CD64 is a neutrophil surface marker that is not expressed in non-sensitized neutrophils. When the neutrophil is exposed to tumor necrosis factor-alpha it is activated and is measured via the CD64 index. Methods: This paper evaluated the relationship between the index value of CD64 on the first day of febrile neutropenia and a positive blood culture. The correlations with white blood count, C-reactive protein and erythrocyte sedimentation rate were also evaluated. This case-control, prospective, diagnostic study included 64 episodes of neutropenia. Case group (n = 14) comprised positive blood cultures, and the control group (n = 50), negative blood cultures. Results: The median rates of CD64 were 2.1 (a ± 3.9) in the case group and 1.76 (a ± 5.02) in the control group. There was no correlation between the value of the CD64 index and blood cultures. The CD64 index was also not correlated with C-reactive protein positivity. Further- more, the CD64 index was not able to predict blood culture positivity. The sensitivity was 64.3%, the specificity was 42%, the positive predictive value was 23.7% and the negative predictive value was 80%. For C-reactive protein, the sensitivity, specificity, positive predictive value, and negative predictive value were 71.4%, 32%, 22.7%, and 80%, respectively. Conclusion: The CD64 index is not suitable for predicting the positivity of blood cultures in this specific population of patients with febrile neutropenia.

Hematopoietic stem cell transplantation is the curative option for patients with myelodysplastic syndrome; however, it requires a long post-transplantation follow-up. A 53-year-old woman with a diagnosis of myelodysplastic syndrome underwent related donor allogeneic hematopoietic stem cell transplantation in July 2006. Three months after transplantation, a comparative short tandem repeat analysis between donor and recipient revealed full chimerism, indicating complete, healthy bone marrow reconstitution. Three years and ten months after hematopoietic stem cell transplantation, the patient developed leukopenia and thrombocytopenia. Another short tandem repeat analysis was carried out which showed mixed chimerism (52.62%), indicating relapsed disease. A donor lymphocyte infusion was administered. The purpose of donor lymphocyte infusion is to induce a graft-versus-leukemia effect; in fact, this donor's lymphocyte infusion induced full chimerism. Successive short tandem repeat analyses were performed as part of post-transplantation follow-up, and in July 2010, one such analysis again showed mixed chimerism (64.25%). Based on this finding, a second donor lymphocyte infusion was administered, but failed to eradicate the disease. In September 2011, the patient presented with relapsed disease, and a second related donor allogeneic hematopoietic stem cell transplantation was performed. Subsequent short tandem repeat analyses revealed full chimerism, indicating complete bone marrow reconstitution. We conclude that quantitative detection of mixed chimerism is an important diagnostic tool that can guide early therapeutic intervention.