Acute myeloid leukemia with t(X;6)9p11;q23);MYB-GATA1 and female sex: GATA1 insufficiency may be insufficient for pathogenesis.

Pediatric acute myeloid leukemia (AML) is genetically heterogenous (Olsson et al., 2016). t(X;6)(p11;q23) is a rare but recurrent chromosomal translocation in infant AML thought to be associated with male sex and basophilic differentiation (Dastugue et al.

Quantification of NG2-positivity for the precise prediction of KMT2A gene rearrangements in childhood acute leukemia.

It has long been known that there is a link between neuron glial antigen 2 (NG2) surface expression and KMT2A gene rearrangements in acute leukemia (AL). However, the exact levels of NG2 positivity that predict the presence of KMT2A rearrangement are not known. The current study focuses on a cohort of 505 pediatric AL patients who showed any level of positive NG2 expression (greater than 1% of cells) for whom comprehensive genetic data were available.

[Driver Mutations in Acute Myeloid Leukemia with Inversion of Chromosome 16].

Certain subtypes of acute myeloid leukemia occur as a result of the cooperation of several events these are, the formation of fusion genes as a result of chromosomal rearrangements, which leads to the disruption of cell differentiation, and the emergence of mutations that enhance cellular proliferation by activating intracellular signaling pathways. High-throughput sequencing methods reveal characteristic mutation spectra in leukemia associated with different chromosomal disorders. However, the role of mutation events in malignant cell transformation processes remains obscure.

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.

[Mutational Profiling of Pediatric Myeloid Leukemia Subtypes without Clinically Significant Chromosomal Aberrations].

The discovery of novel significant molecular and genetic markers is important for the diagnostics, prognosis, and therapy selection in hematological malignancies. Distinct cytogenetic aberrations leading to the formation of fusion genes are found in more than 40% of pediactric cases of acute myeloid leukemia (AML); however, the tumor cells in approximately 20% of these patients display cytogenetically normal karyotype (NK-AML). Here we present the analysis of the mutational profiles of leukemic cells collected from pediatric AML cases without known clinically significant chromosomal aberrations aimed at identifying AML specific markers.

Acute myeloid leukemia with t(10;11)(p11-12;q23.3): Results of Russian Pediatric AML registration study.

Introduction: Translocations involving the KMT2A gene (also known as MLL) are frequently diagnosed in pediatric acute leukemia cases with either lymphoblastic or myeloid origin. KMT2A is translocated to multiple partner genes, including MLLT10/AF10 localizing at chromosomal band 10p12. KMT2A-MLLT10 is one of the common chimeric genes diagnosed in acute leukemia with KMT2A rearrangement (8%), especially in acute myeloid leukemia (AML; 18%).

Clinical significance of cytogenetic changes in childhood T-cell acute lymphoblastic leukemia: results of the multicenter group Moscow-Berlin (MB).

The prognostic significance of genetic lesions in T-cell ALL still needs to be elucidated. Karyotyping and FISH were performed in samples from 120 patients with T-cell ALL registered in the trial Moscow-Berlin 2008. Most frequent rearrangements were TLX3 (N = 29; 24%) and TAL1 (N = 18; 15%), followed by KMT2A (N = 6; 5%), TLX1 (N = 5; 4.

[Age-related characteristics of the efficacy of different glucocorticosteroids in the therapy of acute lymphoblastic leukemia].

Aim: To determine predictors for decision-making on a differential approach to choosing glucocorticosteroids (GCS) for children and adolescents with acute lymphoblastic leukemia (ALL).

Subjects And Methods: The analysis covered 1064 primary patients aged to 1 to 18 years with ALL who had been registered at the clinics of Russia and Belorussia in April 2002 to November 2006. Before induction therapy, the patients were randomized into a dexamethasone (DEXA) 6 mg/m2 group (n=539) and a methylprednisolone (MePRED) 60 mg/m2 one (n=525).

Development of T-cell acute lymphoblastic leukemia in a patient in very long lasting complete remission of juvenile myelomonocytic leukemia.

Juvenile myelomonocytic leukemia (JMML) occurs with an incidence of 1.2 per million children a year, and represents 18% to 30% of all myelodysplastic (MDS) and myeloproliferative (MPS) disorders in the age group below 15, being by far the most common MDS/MPS in children younger than 4 years. The only therapeutic approach which results in a definitive cure of patients with JMML is myeloablative chemo-therapy/radio-therapy, followed by allogeneic hematopoietic cell transplantation.

[Opsoclonus-myoclonus syndrome in children].

To study clinical peculiarities of parainfectious opsoclonus-myoclonus syndrome (OMS) in children and to elaborate approaches to its pharmacotherapeutic correction, 20 children, including 12 girls and 8 boys, have been examined using neurological, neurophysiological, immunological and virological methods along with magnetic resonance tomography (MRT). Age-at-disease-onset was from 8 months to 3 years old. The development of neurological symptoms was related to a virus infection (55% of cases) or vaccination (15%).

[Automatic erythrocytometry in a robotized microscope MEKOS-Ts1].

Measurements of the form and size of erythrocytes are needed in the diagnosis of a number of diseases. However, such measurements, if made manually, are a labor-consuming and often inaccurate method, which ensures the determination of a very limited number of parameters. Hardware/software unit MEKOS-C1 enables an automated examination of blood smear, thus speeding up significantly the analysis and ensuring a more complete and accurate information.

Late Myelosuppressive Action of Programmed Chemotherapy in Acute Lymphoblastic Leukemia in Children.

The capability of peripheral blood leukocytes and bone marrow cells to spontaneous apoptosis was studied in 36 children with ALL remission at various periods after polychemotherapy withdrawal. The enhancement of apoptotic activity has been revealed to be the universal mechanism of delayed effect of antileukemic chemotherapy for all the compartments of hemopoiesis, including granulocyte/macrophage precursors. The expression of this phenomenon is decreasing with the time period elapsed after treatment withdrawal.

[Increased expression of monocytic cell adhesion molecules and formation of monocyte-thrombocyte aggregates in coronary restenosis].

Aim: To examine expression of superficial antigens by blood monocytes and granulocytes as well as the number of leukocyte-platelet complexes forming in in vitro activation in patients subjected to coronary angioplasty; to analyse changes in these parameters in coronary restenosis.

Material And Methods: Membrane expression of leukocytic antigens and the number of leukocyte-platelet complexes after activation in the whole blood were measured by direct immunofluorescence and flow cytometry in 24 patients who have undergone stenting of coronary arteries. 14 of them had angiographically confirmed restenosis.

[The role of Mac-1 and ICAM-1 molecules in adhesion of cells on fibronogen and its degradation products].

Monocytic cell adhesion to immobilized fibrinogen and fibrinogen degradation products, and involvement of integrins Mac-1 and immunoglobulin-like ICAM-1 adhesion molecules in these processes were investigated. Fibrinogen cleavage with plasmin down-regulated adhesion of cells with predominant Mac-1 expression; in contrast, the attachment of ICAM-1-expressing was up-regulated. By means of function-blocking anti-Mac-1 and anti-ICAM-1 antibodies, and immobilization of known fibrinogen degradation products, it was shown that Mac-1 molecules mediated cell adhesion predominantly to fibrinogen, and its early degradation products, fragments X and Y, while ICAM-1 participated in cell attachment to X- and Y-fragments, rather than to intact fibrinogen or late degradation products, fragments D and E.

[Results of treatment of acute leukemia in children using intensive therapy programs].

The authors report the results of the treatment according to the programs BFM-ALL-90 and BFM-AML-83 and 87. A total of 110 children with acute lymphoblastic leukemia (ALL) and 35 with acute myeloblastic leukemia (AML) were treated with remission rate 94.5% and 74.

[T and B components of the immune system in acute bronchopulmonary diseases in children with thymomegaly and without it].

The immune status was estimated comprehensively and indicators of the level I and II tests of T and B components of the immunity system were defined in 120 children with thymomegaly (group I), in 30 children with unenlarged thymus (group II), and in 40 practically healthy children with unestablished size of the thymus, with a favourable family and personal disease history, who had never fallen ill before the immunologic examination (group III). The children belonging to groups I and II were examined at the acute disease period, during convalescence and clinical wellbeing. It has been established that during the acute bronchopulmonary disease, the group I and II children manifested the same regularities of immune response to the action of an antigenic stimulus.

[State of nucleolus-forming regions in bone marrow and blood cells in acute leukemia in children].

The study of the activity of nucleolus-forming areas in bone marrow and blood cells in 67 children with acute leukemia has shown the parameter variability depending on histogenetic affiliation, differentiation degree and on the proliferative activity of the cells.

[Evaluation of the pool of mature circulating lymphocytes in children with acute leukemia].

In children with acute leukemia, at the initial period of the disease the absolute number of T-lymphocytes is within the normal range, when the values of the total number of leucocytes is low or normal, and it is increased in cases with high initial leucocytosis. Dissociation of T-cell marker signs in the lymphocyte population has been revealed that evidences the presence of functionally defective T-cells in the circulation. The value of the relative content of E+ T-cells over 10% in the circulation is of prognostic significance.