Long-Term Outcomes of Childhood Acute Lymphocytic Leukemia Treated with Adapted Berlin-Frankfurt-Münster (BFM) Protocols: A Multicentric Analysis from a Developing Country.

INTRODUCTION: The objective of the current study was to determine the survival probabilities of children and adolescents with acute lymphocytic leukemia treated with adapted Berlin-Frankfurt-Münster (BFM) protocols and compare our results with the original BFM reports. METHODS: This retrospective study included 695 patients up to 19 years old treated with adapted BFM protocols between 1997 and 2018 in four hospitals in Rio de Janeiro. The 1997-2007 and 2008-2018 cohorts were analyzed separately. RESULTS: More than half of the patients were stratified into the high-risk BFM classification. Overall and event-free survivals were, in the 1997-2007 period, respectively, 88% and 80% (BFM standard risk group-SRG), 75% and 67% (intermediate risk group-IRG), and 48% and 33% (high-risk group-HRG). The corresponding numbers for the 2008-2018 period were 93% and 84% (SRG), 75% and 63% (IRG), and 64% and 57% (HRG). In the second period, both the OS (HR = 0.71, p = 0.011) and EFS (HR = 0.62, p < 0.001) were higher. Except for the intermediate-risk group, the latter results are comparable to the BFM. CONCLUSION: The BFM protocol adaptations can be safely implemented in developing countries, accounting for local specificities.

A Novel Constitutional t(3;8)(p26;q21) and ANKRD26 and SRP72 Variants in a Child with Myelodysplastic Neoplasm: Clinical Implications.

BACKGROUND: Childhood myelodysplastic neoplasm (cMDS) often raises concerns about an underlying germline predisposition, and its verification is necessary to guide therapeutic choice and allow family counseling. Here, we report a novel constitutional t(3;8)(p26;q21) in a child with MDS, inherited from the father, the ANKRD26 and SRP72 variants from the maternal origin, and the acquisition of molecular alterations during MDS evolution. CASE PRESENTATION: A 4-year-old girl showed repeated infections and severe neutropenia. Bone marrow presented hypocellularity with dysplastic features. The patient had a t(3;8)(p26;q21)c identified by G-banding and FISH analysis. The family nucleus investigation identified the paternal origin of the chromosomal translocation. The NGS study identified ANKRD26 and SRP72 variants of maternal origin. CGH-array analysis detected alterations in PRSS3P2 and KANSL genes. Immunohistochemistry showed abnormal p53 expression during the MDS evolution. CONCLUSION: This study shows for the first time, cytogenetic and genomic abnormalities inherited from the father and mother, respectively, and their clinical implications. It also shows the importance of investigating patients with constitutional cytogenetic alterations and/or germline variants to provide information to their family nucleus for genetic counseling and understanding of the pathogenesis of childhood MDS.

Updating recommendations of the Brazilian Group of Flow Cytometry (GBCFLUX) for diagnosis of acute leukemias using four-color flow cytometry panels

ABSTRACT Introduction: Flow cytometry has become an increasingly important tool in the clinical laboratory for the diagnosis and monitoring of many hematopoietic neoplasms. This method is ideal for immunophenotypic identification of cellular subpopulations in complex samples, such as bone marrow and peripheral blood. In general, 4-color panels appear to be adequate, depending on the assay. In acute leukemias (ALs), it is necessary identify and characterize the population of abnormal cells in order to recognize the compromised lineage and classify leukemia according to the WHO criteria. Although the use of eightto ten-color immunophenotyping panels is wellestablished, many laboratories do not have access to this technology. Objective and Method: In 2015, the Brazilian Group of Flow Cytometry (Grupo Brasileiro de Citometria de Fluxo, GBCFLUX) proposed antibody panels designed to allow the precise diagnosis and characterization of AL within available resources. As many Brazilian flow cytometry laboratories use four-color immunophenotyping, the GBCFLUX has updated that document, according to current leukemia knowledge and after a forum of discussion and validation of antibody panels. Results: Recommendations for morphological analysis of bone marrow smears and performing screening panel for lineage (s) identification of AL were maintained from the previous publication. The lineage-oriented proposed panels for B and T cell acute lymphoblastic leukemia (ALL) and for acute myeloid leukemia (AML) were constructed for an appropriate leukemia classification. Conclusion: Three levels of recommendations (i.e., mandatory, recommended, and optional) were established to enable an accurate diagnosis with some flexibility, considering local laboratory resources and patient-specific needs.

Flow Cytometry Immunophenotyping for Diagnostic Orientation and Classification of Pediatric Cancer Based on the EuroFlow Solid Tumor Orientation Tube (STOT).

Early diagnosis of pediatric cancer is key for adequate patient management and improved outcome. Although multiparameter flow cytometry (MFC) has proven of great utility in the diagnosis and classification of hematologic malignancies, its application to non-hematopoietic pediatric tumors remains limited. Here we designed and prospectively validated a new single eight-color antibody combination-solid tumor orientation tube, STOT-for diagnostic screening of pediatric cancer by MFC. A total of 476 samples (139 tumor mass, 138 bone marrow, 86 lymph node, 58 peripheral blood, and 55 other body fluid samples) from 296 patients with diagnostic suspicion of pediatric cancer were analyzed by MFC vs. conventional diagnostic procedures. STOT was designed after several design-test-evaluate-redesign cycles based on a large panel of monoclonal antibody combinations tested on 301 samples. In its final version, STOT consists of a single 8-color/12-marker antibody combination (CD99-CD8/numyogenin/CD4-EpCAM/CD56/GD2/smCD3-CD19/cyCD3-CD271/CD45). Prospective validation of STOT in 149 samples showed concordant results with the patient WHO/ICCC-3 diagnosis in 138/149 cases (92.6%). These included: 63/63 (100%) reactive/disease-free samples, 43/44 (98%) malignant and 4/4 (100%) benign non-hematopoietic tumors together with 28/38 (74%) leukemia/lymphoma cases; the only exception was Hodgkin lymphoma that required additional markers to be stained. In addition, STOT allowed accurate discrimination among the four most common subtypes of malignant CD45- CD56++ non-hematopoietic solid tumors: 13/13 (GD2++ numyogenin- CD271-/+ nuMyoD1- CD99- EpCAM-) neuroblastoma samples, 5/5 (GD2- numyogenin++ CD271++ nuMyoD1++ CD99-/+ EpCAM-) rhabdomyosarcomas, 2/2 (GD2-/+ numyogenin- CD271+ nuMyoD1- CD99+ EpCAM-) Ewing sarcoma family of tumors, and 7/7 (GD2- numyogenin- CD271+ nuMyoD1- CD99- EpCAM+) Wilms tumors. In summary, here we designed and validated a new standardized antibody combination and MFC assay for diagnostic screening of pediatric solid tumors that might contribute to fast and accurate diagnostic orientation and classification of pediatric cancer in routine clinical practice.

Minimal residual disease assessment in acute lymphoblastic leukemia by 4-color flow cytometry: Recommendations from the MRD Working Group of the Brazilian Society of Bone Marrow Transplantation

Abstract Introduction: The minimal residual disease (MRD) status plays a crucial role in the treatment of acute lymphoblastic leukemia (ALL) and is currently used in most therapeutic protocols to guide the appropriate therapeutic decision. Therefore, it is imperative that laboratories offer accurate and reliable results through well standardized technical processes by establishing rigorous operating procedures. Method: Our goal is to propose a monoclonal antibody (MoAb) panel for MRD detection in ALL and provide recommendations intended for flow cytometry laboratories that work on 4-color flow cytometry platforms. Results and conclusion: The document includes pre-analytical and analytical procedures, quality control assurance, technical procedures, as well as the information that needs to be included in the reports for clinicians.

Recombinant L-Asparaginase from Zymomonas mobilis: A Potential New Antileukemic Agent Produced in Escherichia coli.

L-asparaginase is an enzyme used as a chemotherapeutic agent, mainly for treating acute lymphoblastic leukemia. In this study, the gene of L-asparaginase from Zymomonas mobilis was cloned in pET vectors, fused to a histidine tag, and had its codons optimized. The L-asparaginase was expressed extracellularly and intracellularly (cytoplasmically) in Escherichia coli in far larger quantities than obtained from the microorganism of origin, and sufficient for initial cytotoxicity tests on leukemic cells. The in silico analysis of the protein from Z. mobilis indicated the presence of a signal peptide in the sequence, as well as high identity to other sequences of L-asparaginases with antileukemic activity. The protein was expressed in a bioreactor with a complex culture medium, yielding 0.13 IU/mL extracellular L-asparaginase and 3.6 IU/mL intracellular L-asparaginase after 4 h of induction with IPTG. The cytotoxicity results suggest that recombinant L-asparaginase from Z. mobilis expressed extracellularly in E.coli has a cytotoxic and cytostatic effect on leukemic cells.