[Removal of a dermoid cyst of the floor of the mouth in a patient with severe hemophilia A]. / Udalenie dermoidnoi kisty dna rta u bol'nogo tyazheloi formoi gemofilii A.

The article presents a case of a surgical treatment of removing a dermoid cyst of the floor of the oral cavity in a patient with severe hemophilia A. A detailed analysis was carried out of the surgical operation, postoperative management, coagulation factor replacement therapy and accompanying therapy, as well as the features of anesthesia, which allowed a surgical intervention without any hemorrhagic and infectious complications.

[The burden of COVID-19 in a heterogeneous population of immunocompromised patients - realities of the postpandemic].

On July 3, 2023, an interdisciplinary Council of Experts "The burden of COVID-19 in a heterogeneous population of immunocompromised patients - post-pandemic realities" was held in Moscow with leading experts in pulmonology, rheumatology, hematology, oncology, nephrology, allergology-immunology, transplantation, and infectious diseases. The aim of the meeting was to discuss the current clinical and epidemiologic situation related to COVID-19, the relevance of disease prevention strategies for high-risk patients. The experts addressed the following issues: 1) the disease burden of COVID-19 in 2023 for patients with immunodeficiency in different therapeutic areas; 2) the place of passive immunization with monoclonal antibodies as a method of COVID-19 prophylaxis among immunocompromised patients; 3) prerequisites for the inclusion of passive immunization of immunocompromised patients into routine clinical practice.

Dynamics of Changes in the Properties of Multipotent Mesenchymal Stromal Cells in Patients with Acute Leukemia.

In acute leukemia, the stromal microenvironment of the bone marrow that regulates hematopoiesis is modified under the influence of malignant cells. Chemotherapy also adversely affects stromal cells. Multipotent mesenchymal stromal cells (MSC) are involved in the formation of the stromal microenvironment and in the regulation of normal and tumor hematopoietic cells. The properties of MSC from the bone marrow of patients with acute myeloid and lymphoid leukemia were studied at the onset of the disease and after achieving remission. The immunophenotype and the level of gene expression were analyzed in MSC of 34 patients. In MSC from patients with acute leukemia, the expression of CD105 and CD274 was significantly reduced in comparison with MSC from healthy donors. At the onset of the disease, the expression of IL6, JAG1, PPARG, IGF1, and PDGFRA was enhanced, while the expression of IL1B, IL8, SOX9, ANG1, and TGFB was reduced. All these changes affect the course of the disease in patients and can be the targets of therapeutic intervention.

Differences in the Differentiation Potential and Relative Levels of Gene Expression in the Bone Marrow-Derived Fibroblast Colony-Forming Units in Patients during the Onset of Aplastic Anemia Depending on the Disease Severity.

The differentiation potential of individual clones of fibroblast CFU (CFU-F) was studied and the relative expression level of genes was analyzed in the culture of CFU-F from the bone marrow in patients with non-severe and severe forms of aplastic anemia at the onset of the disease. The differentiation potential of CFU-F clones was determined by the relative expression of marker genes using quantitative PCR. In aplastic anemia, the ratio of CFU-F clones with different differentiation potential changes, but the molecular mechanisms of this phenomenon are different in non-severe and severe aplastic anemia. In the culture of CFU-F in non-severe and severe aplastic anemia, the relative expression level of genes associated with the maintenance of the hematopoietic stem cell in the bone marrow niche changes, but the decrease in the expression of immunoregulatory genes occurs in severe form only, which may reflect differences in the pathogenesis of non-severe and severe aplastic anemia.

Biogenesis of Mitochondria in Multipotent Mesenchymal Stromal Cells in Patients with Acute Leukemia.

In patients with acute leukemia, not only normal hematopoiesis, but also bone marrow stromal microenvironment is damaged. Multipotent mesenchymal stromal cells (MSC) are essential for the formation and function of the stromal microenvironment. Analysis of changes in MSC is important for the development of new approaches to leukemia therapy. The metabolism of mitochondria in MSC, relative content of mitochondrial DNA, and expression levels of genes encoding PGC-1α and Nrf2 proteins, important regulators of biogenesis, were studied using real-time PCR. Relative content of mitochondrial DNA does not change in MSC of acute leukemia patients at the onset of disease or in remission. Relative expression level of the gene encoding PGC-1α protein in MSC does not change significantly. However, relative expression level of the gene encoding Nrf2, an important antioxidant activity regulator, insignificantly decreases in patients at the onset of acute leukemia, and this decrease becomes significant upon reaching remission.

Differences in Protein Secretion by Multipotent Mesenchymal Stromal Cells Effective and Ineffective in the Prevention of Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation.

Multipotent mesenchymal stromal cells (MSC) were administered to patients after allogeneic hematopoietic stem cell transplantation to prevent the development of acute graft-versus- host disease (GVHD). The injection of MSC did not always prevent the development of GVHD. The aim of the work was to compare the secretome of MSC effective and ineffective in the prevention of GVHD. MSC were obtained from the bone marrow of hematopoietic stem cells donors. The secretome was studied using a TripleTOF 5600+ mass spectrometer with a NanoSpray III ion source coupled to a NanoLC Ultra 2D Plus nano-HPLC System. A total of 1,965 proteins were analyzed. Analysis of the secretome of effective and ineffective MSC samples revealed significant differences in the secretion of 1,119 proteins associated with ribosomes, exosomes, focal contacts, and others. Analysis of proteins secreted by MSC can be used to identify prognostically effective samples.

Bone Marrow Multipotent Mesenchymal Stromal Cells from Patients with Aplastic Anemia Retain Their Ability to Support Hematopoietic Precursors despite Pronounced Changes in Gene Expression.

The properties of bone marrow-derived multipotent mesenchymal stromal cells (MSC) of patients with aplastic anemia at the onset of the disease are studied insufficiently. The aim of this work was to test the ability of MSC from patients with aplastic anemia to maintain hematopoietic precursors and to analyze the expression of genes associated with hematopoiesis and immune response. The ability of MSC to maintain hematopoietic precursors was determined by counting cobblestone area-forming cells; gene expression was analyzed by quantitative PCR. It was shown that MSC of patients with aplastic anemia preserve their ability to maintain hematopoietic precursors. Pronounced changes in the expression of the VEGFA and ANGPT1 genes were found. MSC from aplastic anemia patients with PNH clone significantly differ from those from aplastic anemia patients without PNH clone in terms of the expression of the SDF1, IL1R, and VEGFA genes. Changes in gene expression can be associated with the pathogenesis of the disease.

Changes in Bone Marrow Stromal Progenitor Cells in Patients with Hematoblastosis at the Onset of the Disease.

Multipotent mesenchymal stromal cells (MSC) are the key regulators of hematopoiesis. We studied changes in MSC characteristics in patients with myeloid leukemia and patients with lymphoproliferative diseases. MSC were obtained from the bone marrow of patients at the time of diagnostic puncture using a standard technique. Their proliferative potential and expression of genes associated with differentiation and regulation of hematopoiesis were studied. The total cell production of MSC in patients with leukemia at the onset of the disease did not differ from that in the group of healthy donors. The relative expression of the IL6, TGFb1 and TGFb2, PPARG genes was similar in all patients. The relative expression of the JAG1, LIF, IGF1, CSF1, IL1b, and IL1bR1 genes in MSC of patients with leukemia was enhanced and the relative expression of SDF1 was unchanged in comparison with MSC from donors. MSC from patients with leukemia were characterized by enhanced relative expression of PDGFRA and PDGFRB, and reduced expression of SOX9. Changes functions of the stromal microenvironment in patients with hemoblastoses attested to the role of stromal cells in the maintenance and spread of tumor cells.

Comparison of polymerase chain reaction and flow cytometry for measuring telomere length of human leukocytes.

Telomere length can be measured by polymerase chain reaction (PCR), allowing to obtain the absolute length of telomeres (ALT) in base pair, and by flow cytometry, which can only estimate the relative telomere length. The aim of the study was to compare the results of the two methods and to develop an accurate and reliable way of converting the relative telomere length to absolute. The peripheral blood from 21 donors was analyzed. Measurement of leukocyte telomere length by flow cytometry was carried out using a commercial Telomere PNA Kit / FITC (Dako, Denmark) with two CytoFLEX flow cytometers (Beckman Coulter, China) and BD FACSCanto II (Becton Dickinson, USA), obtaining the molecular equivalent of fluorescence (MEF). To measure telomere length by real-time PCR, calibrators with a known number of telomeric repeats were prepared. Two quantitative PCRs were carried out: one for telomeric repeats, the other for determining the number of genome-equivalents of DNA, three times for each sample, which made it possible to calculate ALT. A strong direct relationship was found between the MEF obtained with BD FACSCanto II and CytoFLEX (r = 0.97). Analysis of PCR and flow cytometry results showed a significant correlation between ALT and MEF. We calculated the regression equations of ALT and MEF for CytoFLEX - y = 0.0043x (r = 0.84) and for BD FACSCanto II - y = 0.0051x (r = 0.82). Correlation analysis showed a high comparability of telomere lengths measured by two methods. The obtained regression equations allow converting the results of flow cytometry into absolute values, allowing the comparison of the results of different research groups and the use of this method in clinical trials.

[Development of program therapy for patients with acute myeloid leukemia under the age of 60 years, based on the principles of differentiated effects].

AIM: To analyze the results of treatment in patients with acute myeloid leukemia (AML) within protocols AML-17 and modified AML-17 (mOML-17) as part of two consecutive pilot studies in order to develop the best treatment strategy for AML patients aged below 60 years. MATERIALS AND METHODS: The study included 89 AML patients who were aged below 60 years and received treatment within the AML-17 and mOML-17 protocols. Cytogenetic and molecular genetic studies were performed in all patients. The presence of mutations in the FLT3, NPM1, CEBPa genes was assessed by fragment analysis. 35 patients underwent a study for mutTP53, mutRUNX1 using next generation sequencing (NGS). The minimum residual population of tumor cells was evaluated by multicolor flow cytometry. Statistical analysis was performed using the procedures of the SAS 9.3 package. RESULTS: Complete remission (CR) was achieved in 89.7% of patients treated with intensive chemotherapy (CT) courses and in 52.4% of patients treated with low-dose CT courses. 8.8% of intensively treated patients were refractory to therapy, and 38% did not respond to low-dose exposure. The early mortality rate was 3%. The overall survival and disease-free 3-year survival for patients included in 2 consecutive studies was were 60% and 67%, respectively. The level of minimal residual disease (MRD) after the first course of induction CT was an important prognostic indicator. The three-year relapse-free survival for patients in whom CR was achieved after the first course of induction CT and in whom MRD was not detected (MRD-negative status was obtained) was 90% compared to 43% for patients who were MRD positive after the first course of induction CT (p=0.00001). CONCLUSION: The key factor that significantly affects the long-term results of therapy is the rate of MRD after the first course of induction CT.

[Li-Fraumeni syndrome in adult patients with acute lymphoblastic leukemia].

BACKGROUND: LiFraumeni syndrome (LFS) is a rare, autosomal dominant, hereditary disorder that is characterized by an increased risk for certain types of cancer, acute lymphoblastic leukemia (ALL), particularly. Germline TP53 mutations are associated with LFS. Genetic counseling and follow-up is essential for patients with LFS and their relatives. Special therapeutic approaches are needed for treatment of oncological disease in these patients. The article presents a series of clinical cases of patients with ALL and SLF, considers general issues of diagnosis and treatment of adult patients with this hereditary genetic syndrome. AIM: Describe clinical observations of patients with acute lymphoblastic leukemia (ALL) and LFS and consider general issues of diagnosis and treatment of adult patients with LFS and ALL. MATERIALS AND METHODS: TP53 gene mutations were screened using Sanger sequencing in 180 de novo patients with Ph-negative (B- and T-cell) and Ph-positive ALL treated by Russian multicenter protocols (ALL-2009, ALL-2012, ALL-2016) at the National Research Center for Hematology, Moscow, Russia, and at the hematology departments of regional clinics of Russia (multicenter study participants). RESULTS: TP53 gene mutations were found in 7.8% (n=14) of de novo ALL patients. In patients, whose biological material was available TP53 gene mutational status was determined in non-tumor cells (bone marrow and peripheral blood during remission, bone marrow samples after allogeneic hematopoietic stem cells transplantation and in tissue of non-hematopoietic origin) for discriminating germline mutations. The analysis included 5 patients (out of 14 with TP53 mutations), whose non-tumor biological material was available for research. Germline status was confirmed in 4 out of 5 B-cell ALL (n=3), T-cell ALL (n=1) investigated patients. CONCLUSION: Practical value of the research is the observation that the greater part of TP53 gene mutations in patients with Ph-negative B-cell ALL are germinal and associated with LFS.

[Allogeneic hematopoietic stem cell transplantation in patients with multiple myeloma].

AIM: To analyze the effectiveness of allogeneic hematopoietic stem cell transplantation (allo-HSCT) from a related HLA-identical donor in patients with multiple myeloma (MM). MATERIALS AND METHODS: From 2013 to 2018, the study included 8 patients (6 men, 2 women) aged from 27 to 55 years (median 39 years) with MM who underwent allo-HSCT from a related HLA-identical donor (7 patients after auto-HSCT, in 1 case without previous auto-transplantation). All patients required 2 or more lines of induction therapy, while the achieved antitumor effect was unstable. Before allo-HSCT, complete and very good partial remission was determined in isolated cases, in 4 patients the response was regarded as partial remission, stabilization in 1 observation, progression in 1 patient. All patients underwent reduced intensity conditioning (fludarabine 30 mg/m2 6 days + busulfan 4 mg/kg 2 days). Immunosuppressive therapy included the administration of antithymocyte globulin and post-transplant cyclophosphamide. RESULTS: Severe acute GVHD (grade 34) was observed in 3 (37.5%) cases, which resulted in death in 1 case. A stable antitumor response was achieved in 5 (62.5%) patients, complete remission lasts for 2986 months after allo-HSCT. Specific therapy for these patients is not carried out. The 7-year progression-free survival rate was 75%, the 7-year overall survival rate was 84%, with a median follow-up of 65 months. The transplant-related mortality was 12.5%. CONCLUSION: Allo-HSCT is considered as an alternative method of therapy for young patients with aggressive MM. Allo-HSCT in MM in some cases leads to long-term immunological control of the tumor.

[Multiple primary tumor of hematopoietic tissue: myeloid sarcoma in combination with mantle cell lymphoma. Case report].

The prevalence of multiple primary tumors has significantly increased last time. The question of choosing the optimal tactics of therapy today not fully resolved. Particular interest is the simultaneous detection of two neoplasms of similar origin in one study biopsy material. This publication presents a case of simultaneous diagnosis of myeloid sarcoma and mantle cell lymphoma in a 65-year-old patient, which required use of two different chemotherapy protocols. This example shows the need to use an extended diagnostic approach at all stages of the therapy, which allows choosing right tactics of therapy and achieving complete remission of two neoplasms.

[Repeated haploidentical allogeneic hematopoietic stem cell transplantation with TCR αß/CD19 depletion in patient with primary myelofibrosis. Case report].

Indications of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with primary myelofibrosis are intermediate-2 and high-risk group of DIPSS (Dynamic International Prognostic Scoring System), beginning of the disease in childhood. The other adverse factors affect engraftment and survival after allo-HSCT, example partialy matched donor. But the result of allo-HSCT from matched related donors and result of allo-HSCT from haploidentical donors are comparable. The method for haploidentical hematopoietic stem cell transplantation is T-cell-depletion. This is clinical case of T-cell-depleted haploidentical hematopoietic stem cell transplantation in patient with primary myelofibrosis, the diagnosis was established in childhood.

[Extracorporeal cytokine removal in chimeric antigen receptor T-cell therapy associated cytokine release syndrome in patient with acute lymphoblastic leukemia. Case report].

Сytokine release syndrome is the common complication of CAR-T therapy. We report a case of patient with B-cell acute lymphoblastic leukemia developing сytokine release syndrome with shock and multiple organ failure and requiring cytokine removal and hemodiafiltration. Remission of the disease was achieved after CAR-T therapy.

[A case report of familial dyskeratosis congenital. Case report].

Dyskeratosis congenita (DC) is a hereditary syndrome of bone marrow failure, which develops because of telomeres defects and combines with cancer predisposition. Its classical clinical features are skin pigmentation, nail dystrophy, oral leukoplakia (skin-mucosa triad). The goal is to describe the algorithm of diagnosis, clinical specificities of DC and specific treatment for cases of DC in one family. The present report includes descriptions of diagnosis and treatment of family members diagnosed for the first time as having a DC. The report shows an importance of all diagnostic stages: from a medical history and clinical picture to an application of modern high-tech diagnostic methods (flow-FISH, NGS). The report underlines an importance of diagnosis of all family members for excluding an asymptomatic form after a case of DC has been already detected in that family. A high frequency of a toxicity and secondary neoplasia makes it necessary to realize an individual approach at treatment of each patient with DC (the earliest start of androgen treatment, prompt decision of implementation of allogenic hematopoietic stem cell transplantation). The knowledge of pathogenesis, clinical features and principles of diagnosis and therapy of this disease is relevant to pediatricians and hematologists.

[Immunosupressive therapy of aplastic anemia patients: successes and failures (single center experiment 2007-2016)].

Treatment programs for patients with acquired aplastic anemia include two main therapeutic options: allogeneic bone marrow transplantation and combined immunosuppressive therapy (IST). However, combined IST remains the method of choice for most adult AA patients. This study included 120 AA patients who received IST at the National Research Center for Hematology in 20072016. The analysis was applied to 120 patients. Median age was 25 (1765) years, M/F: 66/54, SAA/NSAA: 66%/34%. Effectiveness of IST was carried out in 120 patients with AA. This group did not include 8 SAA patients who died during the first 3 months from the start of treatment from severe infectious complications (early deaths 6.2%) and 2 AA patients who dropped out of surveillance. The observation time was 55 (6120) months. Paroxysmal nocturnal hemoglobinuria (PNH clone) was detected in 67% of AA patients. The median PNH clone size (granulocytes) was 2.5 (0.0199.5)%. The treatment was according to the classical protocol of combined IST: horse antithymocytic globulin and cyclosporin A. Most of patients (87%) responded to combined immunosuppressive therapy. To achieve a positive response, it was sufficient to conduct one course of ATG to 64% of patients, two courses of ATG 24% of patients and 2% of patients responded only after the third course of ATG. A positive response after the first course was obtained in 64% of patients included in the analysis. Most of the responding patients (93%) achieve a positive response after 36 months from the start of treatment. Therefore, the 3rd6th months after the first course of ATG in the absence of an answer to the first line of therapy can be considered the optimal time for the second course of ATG. This tactic allows to get an answer in another 58% of patients who did not respond to the first course of ATG. The probability of an overall 10-year survival rate was 90% (95% confidence interval 83.696.2).

[Multipotent mesenchymal stromal cells application for acute graft versus host disease treatment].

AIM: Analysis of the effectiveness of the MSCs aministration as the second- or third-line therapy of acute GVHD (aGVHD) resistant to glucocorticosteroid treatment. MATERIALS AND METHODS: The study included 35 patients who received MSCs obtained from the bone marrow of healthy donors as a treatment of steroid-resistant aGVHD. The clinical parameters of patients, MSCs cultural characteristics, the MSC expression profile for various genes including those involved in immunomodulation, expression of cells surface markers, the source of MSCs, as well as the frequency and number of MSC administrations were analyzed. RESULTS: Response to therapy was achieved in 74% of cases, a complete response was reached in 13 (37%) patients, partial response/clinical improvement was demonstrated in 13 (37%). This treatment was ineffective in 9 patients. The prediction of a group of patients with good response to MSC therapy turned to be impossible. The differences between the effective and ineffective for the GVHD treatment MSCs samples were found. The effective ones were characterized with a decreased total MSCs production and an increase in the main histocompatibility complex and PDL-1 antigens expression. CONCLUSION: These data allow to select optimal samples for aGVHD treatment that can improve clinical results. aGVHD treatment with MSCs has shown efficacy comparable to other treatment approaches. Given the low percentage of complications and the absence of significant adverse effects, MSC therapy seems to be one of the optimal approaches to the treatment of resistant forms of GVHD.

[Detection of activating mutations in RAS/RAF/MEK/ERK and JAK/STAT signaling pathways].

ISSUE: The study of activating mutations (NRAS,KRAS,FLT3,JAK2,CRLF2genes) of RAS/RAF/MEK/ERK and JAK/STAT signaling pathways in B-cell acute lymphoblastic leukemia (B-ALL) in adult patients which are included in Russian multicenter clinical trials. MATERIALS AND METHODS: Within the multicenter study there were 119 adult patients included withde novoB-ALL. The study was considered as prospective and retrospective. The group withBCR-ABL1-negative B-ALL consisted of up to 93 patients (45 male and 48 female, at the age of 17 to 59, the median age 31), they were treated according to the protocols ALL-2009, ALL-2016. The median follow-up lasted for 19 months (1119). The group withBCR-ABL1-positive B-ALL with up to 26 patients (10 male and 16 female, at the age of 23 to 78, the median age 34 years) was included in the study as well. The treatment was carried out according to the protocols ALL-2009 and ALL-2012 in combination with tyrosine kinase inhibitors. The median follow-up lasted for 23 months (4120). The molecular analysis of activating mutations inNRAS,KRASgenes (RAS/RAF/MEK/ERK signaling pathway) andJAK2,CRLF2genes (JAK/STAT signaling cascade) was performed via Sanger sequencing. The internal tandem duplications (ITDs) inFLT3gene were studied by fragment analysis. The evaluation of CRLF2 expression was fulfilled via flow cytometry. RESULTS: Activating mutations inNRAS,KRAS,FLT3genes were found in 22 (23.6%) patients withBCR-ABL1-negative B-ALL. In total, 23 mutations were revealed in theNRAS(n=9),KRAS(n=12), andFLT3(n=2) genes, according to statistics that was significantly more frequent than withBCR-ABL1-positive B-ALL, these genes mutations were not identified in patients (p=0.007). The frequency of mutations detection inKRASandNRASgenes in patients withBCR-ABL1-negative B-ALL was comparable as 12.9% (12 of 93) to 9.7% (9 of 93), respectively (p=0.488). One patient was simultaneously revealed 2 mutations in theKRASgene (in codons 13 and 61).FLT3-ITD mutations were detected in 3.5% (2 of 57) cases ofBCR-ABL1-negative B-ALL. In patients withBCR-ABL1-positive B-ALLFLT3-ITD mutations were not assessed. Violations in the JAK/STAT signaling cascade were detected in 4 (4.3%) patients withBCR-ABL1-negative B-ALL. They were represented by the missense mutations ofJAK2gene (n=3) and the overexpression of CRLF2 (n=2); in one patient were detected the overexpression of CRLF2 and a mutation inJAK2gene simultaneously. No mutations were found inCRLF2gene. In patients withBCR-ABL1-positive B-ALL noJAK2mutations were detected. As long as analyzing demographic and clinical laboratory parameters between groups of patients with and without mutations, there were no statistically significant differences obtained. In the analyzed groups of patients, long-term therapy results did not differentiate according to the mutations presence inNRAS,KRAS,FLT3,JAK2genes. Also, substantive differences were not shown in the rate of the negative status achievement of the minimum residual disease between patients with and without activating mutations in the control points of the protocol (on the 70th, 133rd and 190th days). CONCLUSION: NRAS,KRAS,FLT3,JAK2activating mutations do not affect the long-term results of the therapy and the rate of the negative status achievement of the minimum residual disease in patients withBCR-ABL1-negative B-ALL treated by the Russian multicenter clinical trials.

[Russian multicenter clinical trials in acute leukemias].

The paper describes the results of 15 consecutive Russian clinical trials in the treatment of different types of acute leukemias, conducted by Russian cooperative group within the last 27-years and included more than 25 hundred patients. It was shown that the 5-years overall survival in AML younger than 60 years patients improved from 20 to 33%, in ALL - from 38 to 65%, in APL - from 0 to 95%. The cooperative work resulted in balanced clinical recommendations and protocols, reproducible in regional hospitals. Though till now there is a big difference in the long term outcome in acute leukemias patients treated in coordinating or regional centers mostly due to much higher early death rate: 7.5-9.5% vs 18-25%. This parameter should be used as criteria of the total efficacy of hematological service in each region of Russia. It became possible within the last years to integrate the minimal residual disease monitoring into clinical trials thus providing a clue parameter for choosing the further therapy - allogeneic stem cell transplantation. Non - chemotherapeutic approach with arsenic trioxide and all - trans retinoid acid had dramatically changed the toxicity and duration of treatment with very high efficacy. The Russian cooperative group was the first that started to include pregnant women with acute leukemias into clinical trials. This prospective and prolonged experience has shown that pregnancy in acute myeloid leukemia is an extremely poor prognostic factor, but it does not influence the outcome in acute lymphoblastic leukemia.