Flow cytometric minimal residual disease measurement accounting for cytogenetics in children with non-high-risk acute lymphoblastic leukemia treated according to the ALL-MB 2008 protocol.

Background: Quantitative measurement of minimal residual disease (MRD) is the "gold standard" for estimating the response to therapy in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Nevertheless, the speed of the MRD response differs for different cytogenetic subgroups. Here we present results of MRD measurement in children with BCP-ALL, in terms of genetic subgroups with relation to clinically defined risk groups.

A Single Dose of PEG-Asparaginase at the Beginning of Induction Not Only Accelerates MRD Clearance but Also Improves Long-Term Outcome in Children with B-Lineage ALL.

Unlabelled: This report presents the results of the assessment of MRD response by multicolor flow cytometry (MFC) with regard to the randomized use of pegylated asparaginase (PEG). In this study, PEG was randomly administered at a dose of 1000 U/m on day 3 of induction therapy in children with B-lineage ALL.

Methods: Conventional induction therapy consisted of dexamethasone, vincristine, and daunorubicin.

The KMT2A recombinome of acute leukemias in 2023.

Chromosomal rearrangements of the human KMT2A/MLL gene are associated with de novo as well as therapy-induced infant, pediatric, and adult acute leukemias. Here, we present the data obtained from 3401 acute leukemia patients that have been analyzed between 2003 and 2022. Genomic breakpoints within the KMT2A gene and the involved translocation partner genes (TPGs) and KMT2A-partial tandem duplications (PTDs) were determined.

Allogeneic Hematopoietic Stem Cell Transplantation Activity in Inborn Errors of Immunity in Russian Federation.

Purpose: Allogeneic hematopoietic stem cell transplantation (HSCT) is an established therapy for many inborn errors of immunity (IEI). The indications for HSCT have expanded over the last decade. The study aimed to collect and analyze the data on HSCT activity in IEI in Russia.

A simple procedure to identify children with B-lineage acute lymphoblastic leukemia who can be successfully treated with low or moderate intensity: Sequential versus single-point minimal residual disease measurement.

Sequential monitoring of minimal residual disease (MRD) by molecular techniques or multicolor flow cytometry (MFC) has emerged over the past two decades as the primary tool to optimize treatment in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The aim of our study was to compare the prognostic power of repeated MFC-MRD measurement with single-point MRD assessment in children with BCP-ALL treated with the reduced-intensity protocol ALL-MB 2008. Data from consecutive MFC-MRD at day 15 and day 36 (end of induction, EOI) were available for 507 children with Philadelphia-negative BCP-ALL.

One-point flow cytometric MRD measurement to identify children with excellent outcome after intermediate-risk BCP-ALL: results of the ALL-MB 2008 study.

Background:  Measurement of minimal residual disease (MRD) with multicolor flow cytometry (MFC) has become an important tool in childhood acute lymphoblastic leukemia (ALL), mainly to identify rapid responders and reduce their therapy intensity. Protocols of the Moscow-Berlin (MB) group use a comparatively low (for standard risk; SR) or moderate (for intermediate risk; ImR) treatment intensity from the onset, based on initial patient characteristics. Recently, we reported that 90% of SR patients-50% B cell precursor (BCP-ALL)-MFC-MRD negative at end of induction (EOI)-had 95% event-free survival (EFS).

Incidence and prognostic value of central nervous system involvement in infants with B-cell precursor acute lymphoblastic leukemia treated according to the MLL-Baby protocol.

Aim: The aim of the study was to evaluate the incidence and prognostic impact of central nervous system (CNS) involvement in infants with B-cell precursor acute lymphoblastic leukemia (BCP-ALL), as well as its relation with minimal residual disease (MRD) data.

Methods: A total of 139 consecutive infants with BCP-ALL from the MLL-Baby trial were studied. Cerebrospinal fluid (CSF) samples were investigated by microscopy of cytospin slides.

Suppressed miR-128-3p combined with TERT overexpression predicts dismal outcomes for neuroblastoma.

Background: Molecular and clinical diversity of neuroblastomas is notorious. The activating TERT rearrangements have been associated with dismal prognosis. Suppression of miR-128-3p may complement and enhance the adverse effects of TERT overexpression.

Lineage Conversion in Pediatric B-Cell Precursor Acute Leukemia under Blinatumomab Therapy.

We report incidence and deep molecular characteristics of lineage switch in 182 pediatric patients affected by B-cell precursor acute lymphoblastic leukemia (BCP-ALL), who were treated with blinatumomab. We documented six cases of lineage switch that occurred after or during blinatumomab exposure. Therefore, lineage conversion was found in 17.

Comparison of minimal residual disease measurement by multicolour flow cytometry and PCR for fusion gene transcripts in infants with acute lymphoblastic leukaemia with KMT2A gene rearrangements.

This study aimed to evaluate the concordance between minimal residual disease (MRD) results obtained by multicolour flow cytometry (MFC) and polymerase chain reaction for fusion gene transcripts (FGTs) in infants with acute lymphoblastic leukaemia (ALL) associated with rearrangement of the KMT2A gene (KMT2A-r). A total of 942 bone marrow (BM) samples from 123 infants were studied for MFC-MRD and FGT-MRD. In total, 383 samples (40.

Prognostic value of minimal residual disease measured by fusion-gene transcript in infants with KMT2A-rearranged acute lymphoblastic leukaemia treated according to the MLL-Baby protocol.

The prognostic value of minimal residual disease (MRD) measured by fusion-gene transcript (FGT) detection was investigated in 76 infants (aged ≤1 year) with acute lymphoblastic leukaemia (ALL) with lysine methyltransferase 2A (KMT2A) rearrangements. Either at the end of induction or at later time-points, FGT-MRD-positivity was associated with poor outcome. FGT-MRD-positivity after first consolidation or first high-risk block detected 46·5% of infants with extremely poor outcome [disease-free survival (SE) 0·06 (0·06), cumulative incidence of relapse (SE) 0·91 (0·05)], which was also confirmed in multivariable analysis.

FLAER-negative CD15+ neutrophils can be used for the simplified screening of suspected PNH cases.

Background: The flow cytometry analysis of GPI-linked proteins on red blood cells and leukocytes is crucial for paroxysmal nocturnal hemoglobinuria (PNH) diagnostics. However, the commonly used multicolor panels cannot be implemented in low-resourced hematology laboratories. In order to develop a simple prediagnostic test for PNH screening, we analyzed the diagnostic accuracy of the two-color (FLAER/CD15) detection of GPI-deficient neutrophils.

Heterogeneity of childhood acute leukemia with mature B-cell immunophenotype.

Background: Flow cytometry (FCM) plays a crucial role in the differential diagnosis of Burkitt lymphoma/leukemia (BL) and B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The presence of surface IgM (sIgM) alone or with light chain restriction indicates a mature blast phenotype (BIV by EGIL) and is usually observed in BL. However, sIgM expression could also be detected in transitional BCP-ALL cases.

Rituximab and reduced-intensity chemotherapy in children and adolescents with mature B-cell lymphoma: interim results for 231 patients enrolled in the second Russian-Belorussian multicentre study B-NHL-2010M.

The value of adding rituximab to chemotherapy in children with aggressive B-cell non-Hodgkin lymphoma (B-NHL) is still insufficiently studied. We enrolled 231 patients [mean age 9 years old (range 2-17); male:female ratio 3·4:1] with Burkitt (BL, 179 patients, 76·7%), diffuse large B-cell (32 patients, 14%), primary mediastinal B-cell (14 patients, 6%), and other (6 patients, 2·6%) B-cell lymphomas in a prospective study of immuno-chemotherapy. Stages were I-II in 32% and III-IV in 68% of the patients.

Reduced vs. standard dose native E. coli-asparaginase therapy in childhood acute lymphoblastic leukemia: long-term results of the randomized trial Moscow-Berlin 2002.

Purpose: Favorable outcomes were achieved for children with acute lymphoblastic leukemia (ALL) with the first Russian multicenter trial Moscow-Berlin (ALL-MB) 91. One major component of this regimen included a total of 18 doses of weekly intramuscular (IM) native Escherichia coli-derived asparaginase (E. coli-ASP) at 10000 U/m during three consolidation courses.

Absolute count of leukemic blasts in cerebrospinal fluid as detected by flow cytometry is a relevant prognostic factor in children with acute lymphoblastic leukemia.

Background: Usually, central nervous system (CNS) involvement in acute lymphoblastic leukemia (ALL) is diagnosed by cytomorphology (CM) of cerebrospinal fluid (CSF) on cytospin slides. Multicolor flow cytometry (MFC) provides the opportunity to detect low numbers of leukemia cells undetectable by CM. The present study aimed at evaluating the clinical significance of MFC for the diagnosis of CNS involvement at initial manifestation of childhood ALL.

The role of nelarabine in the treatment of T-cell acute lymphoblastic leukemia: literature review and own experience.

Aim: The analysis of experience of nelarabine use in refractory/relapsed T-cell acute lymphoblastic leukemia (T-ALL) depending on the immunophenotype and the line of therapy.

Materials And Methods: All the patients with relapsed or refractory T-ALL aged from 0 to 18 years who received treatment with nelarabine as a part of the therapeutic element R6 were included in the study. For all patients a detailed immunological analysis of leukemia cells with discrimination of immunological variants TI, TII, TIII or TIV was performed.

Validation of the United Kingdom copy-number alteration classifier in 3239 children with B-cell precursor ALL.

Genetic abnormalities provide vital diagnostic and prognostic information in pediatric acute lymphoblastic leukemia (ALL) and are increasingly used to assign patients to risk groups. We recently proposed a novel classifier based on the copy-number alteration (CNA) profile of the 8 most commonly deleted genes in B-cell precursor ALL. This classifier defined 3 CNA subgroups in consecutive UK trials and was able to discriminate patients with intermediate-risk cytogenetics.