Publications by authors named "Tatiana Verzhbitskaya"

6 Publications

  • Page 1 of 1

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.

Br J Haematol 2021 06 14;193(6):1151-1156. Epub 2021 Feb 14.

Regional Children's Hospital, Ekaterinburg, Russian Federation.

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. Thus, FGT-MRD measurement at a single time-point clearly identifies infants with ALL who are curable with conventional chemotherapy and those who would benefit only from other treatment approaches.
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June 2021

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

Int J Lab Hematol 2020 Oct 25;42(5):589-593. Epub 2020 May 25.

Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.

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.

Methods: We reanalyzed multicolor data set of 1594 peripheral blood samples of patients screened for PNH applying only two markers (FLAER/CD15). The quantitative positivity/negativity was reported. Then, these results were compared in a blinded manner with previously obtained multicolor data from the same samples.

Results: Among the 1594 samples included in the study, 507 samples were PNH-positive by the multicolor assay. The two-color method revealed 510 PNH-positive samples. The detailed examination of this discrepancy revealed 12 false-positives and 9 false-negatives. Therefore, FLAER/CD15 screening method displayed 98.90% of the diagnostic specificity and 98.22% of the sensitivity.

Conclusion: This simple two-color evaluation of FLAER-negative neutrophils is a highly effective screening test for PNH. Although this approach is not intended to replace the multicolor diagnostic procedure, it could minimize the number of patients requiring a conventional multicolor flow cytometric assay.
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October 2020

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

J Cancer Res Clin Oncol 2019 Nov 28;145(11):2803-2811. Epub 2019 Aug 28.

Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, 1 Samory Mashela St., GSP-7, Moscow, 117997, Russia.

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. These similarities in immunophenotype and ambiguous correspondence with other laboratory findings may challenge the correct BL diagnostics.

Methods: We retrospectively reviewed the available data from immunophenotypic, morphological, cytogenetic, and molecular genetic studies of 146 children (85 boys and 61 girls) with a median age of 10 years (range 0-18 years) who were diagnosed with BL and BCP-ALL. The blasts' immunophenotype was studied by multicolor FCM. The conventional cytogenetic analysis included G-banded karyotyping and fluorescence in situ hybridization (FISH).

Results: In 54 children classified as BIV-ALL according to the EGIL, it was demonstrated that sIgM in a minority of cases can be associated with various types of BCP-ALL. Analysis of the antigen expression profile of 105 patients with verified BL (n = 21) and BCP-ALL (n = 84) showed significant differences in BL and the sIgM(+) vs BCP-ALL immunophenotype. Thus, even in cases of ambiguous sIgM expression, these two diseases could be reliably discriminated by complex immunophenotyping. Moreover, 10 patients (7 boys and 3 girls) with BL leukemic cells did not express sIgM, and they were diagnosed with BL on the basis of other laboratory and clinical signs.

Conclusions: In conclusion, our study shows that BIV subtype is heterogeneous group of leukemia including not only the BL, but also BCP-ALL. In ambiguous cases, only a combination of multiple immunophenotypic, cytomorphologic, and genetic diagnostic technologies can allow the precise discrimination of BL and BCP-ALL and selection of the appropriate treatment scheme.
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November 2019

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

J Cancer Res Clin Oncol 2019 May 6;145(5):1331-1339. Epub 2019 Mar 6.

Regional Children Hospital, 32, S. Deryabina Str., 620149, Ekaterinburg, Russian Federation.

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.

Methods: In 155 children with ALL, CSF samples were studied in parallel by CM and MFC. Patients were treated according to protocol ALL-MB-2008 for childhood ALL. The prognostic impact of the leukemia burden in CSF was determined categorizing the findings as positive/negative. In addition, the absolute blast cell count per 1 ml of CSF was studied as a continuous variable.

Results: CSF positivity was significantly more frequent using MFC compared with CM (35.3% vs. 15.3% of patients). The outcome of MFC-positive and MFC-negative patients was not different in clinically relevant patient risk groups-CNS1, standard and intermediate-risk groups. Using the quantitative approach, at the threshold level of 20 blasts per ml of CSF, patients could be divided into two groups with a significantly different outcome, irrespective of the clinical risk group, the type of CNS-directed therapy, and the CNS status determined by CM.

Conclusions: Our data do not support the concept of re-stratification and modification of therapy based on qualitative CSF investigation by MFC. However, MFC is a highly sensitive technique of CSF investigation improving the definition of CNS involvement in childhood ALL, and quantitative measurement of blast cells in CSF, if well-organized, can be a useful additional tool for stratification of patients in clinical trials.
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May 2019

Prognostic value of initial bone marrow disease detection by multiparameter flow cytometry in children with neuroblastoma.

J Cancer Res Clin Oncol 2019 Feb 2;145(2):535-542. Epub 2019 Jan 2.

Research Institute of Medical Cell Technologies, 22A, K. Marx st, Yekaterinburg, 620026, Russian Federation.

Purpose: Multicolor flow cytometry (MFC) is widely available, fast and has an easy-to perform approach for finding neuroblastoma (NB) cells among normal bone marrow (BM) hematopoietic cells. Aim of the study was to investigate prognostic significance of initial MFC tumor cells' detection in BM of children with NB.

Methods: 51 patients (24 boys and 27 girls) aged from 6 days to 15 years (median age 1 year 3 months) with NB were included in the study. BM samples at the time of diagnosis were obtained from 2 to 5 aspiration sites per patient. CD45(-)CD56(+)CD81(+)GD2(+)-cells were evaluated by MFC.

Results: NB cells were detected in BM by FC more frequently compared to conventional cytomorphology (49.0% and 29.4% patients, respectively, р = 0.043). Patients with NB cells detected in BM by MFC had significantly worse event-free survival and cumulative incidence of relapse/progression [0.24(0.08) and 0.60(0.10), respectively] compared to children with negative result of immunophenotyping [0.85(0.07) and 0.12(0.06), respectively, p < 0.001 in both cases]. BM involvement detection by MFC maintained its prognostic significance in various patients groups. In multivariate analysis, immunophenotyping proved to be an independent prognostic factor when analyzed jointly with other NB risk factors. In 42 patients BM involvement was also studied by RQ-PCR for PHOX2B and TH genes expression. Within groups of patients divided by RQ-PCR positivity, MFC-positivity retained prognostic significance.

Conclusions: Thus flow cytometric BM involvement detection has very strong prognostic impact even stronger than RQ-PCR. It could be used in combination with other parameters for the treatment strategy choice in patients with NB.
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February 2019