Diagnostic workup of acute leukemias of ambiguous lineage.

Acute leukemias of ambiguous lineage (ALAL) comprise acute undifferentiated leukemias (AUL) and mixed-phenotype acute leukemias (MPAL). In the revised fourth edition of the World Health Organization (WHO) classification provided further refinements to the diagnostic criteria for ALAL. Molecular characterization of MPALs using comprehensive next-generation sequencing (NGS) has provided insights into their underlying biology and enabled a deeper understanding of ALAL classification. This review addresses the various components of pathologic assessment to establish a diagnosis of ALAL, and to further subclassify individual cases as AUL or MPAL, with an emphasis on the most up-to-date revisions to diagnostic criteria. In addition, key issues related to the detection of minimal residual disease (MRD) in ALALs and MPALs, and recently uncovered novel molecular diagnostic findings that may be helpful in better distinguishing various types of MPALs from each other, and from their "non-mixed" phenotypic correlates, are also discussed.

Improving Clinical Manufacturing of IL-15 Activated Cytokine-Induced Killer (CIK) Cells.

Cytokine-induced killer (CIK) cells are an immunotherapeutic approach to combat relapse following allogeneic hematopoietic stem cell transplantation (HSCT) in acute leukemia or myelodysplastic syndrome (MDS) patients. Prompt and sequential administration of escalating cell doses improves the efficacy of CIK cell therapy without exacerbating graft vs. host disease (GVHD). This study addresses manufacturing-related issues and aimed to develop a time-, personal- and cost-saving good manufacturing process (GMP)-compliant protocol for the generation of ready-for-use therapeutic CIK cell doses starting from one unstimulated donor-derived peripheral blood (PB) or leukocytapheresis (LP) products. Culture medium with or without the addition of either AB serum, fresh frozen plasma (FFP) or platelet lysate (PL) was used for culture. Fresh and cryopreserved CIK cells were compared regarding expansion rate, viability, phenotype, and ability to inhibit leukemia growth. Cell numbers increased by a median factor of 10-fold in the presence of FFP, PL, or AB serum, whereas cultivation in FFP/PL-free or AB serum-free medium failed to promote adequate CIK cell proliferation (p < 0.01) needed to provide clinical doses of 1 × 106 T cells/kG, 5 × 106 T cells/kG, 1 × 107 T cells/kG, and 1 × 108 T cells/kG recipient body weight. CIK cells consisting of T cells, T- natural killer (T-NK) cells and a minor fraction of NK cells were not significantly modified by different medium supplements. Moreover, neither cytotoxic potential against leukemic THP-1 cells nor cell activation shown by CD25 expression were significantly influenced. Moreover, overnight and long-term cryopreservation had no significant effect on the composition of CIK cells, their phenotype or cytotoxic potential. A viability of almost 93% (range: 89-96) and 89.3% (range: 84-94) was obtained after freeze-thawing procedure and long-term storage, respectively, whereas viability was 96% (range: 90-97) in fresh CIK cells. Altogether, GMP-complaint CIK cell generation from an unstimulated donor-derived PB or LP products was feasible. Introducing FFP, which is easily accessible, into CIK cell cultures was time- and cost-saving without loss of viability and potency in a 10-12 day batch culture. The feasibility of cryopreservation enabled storage and delivery of sequential highly effective ready-for-use CIK cell doses and therefore reduced the number of manufacturing cycles.

Transcripto E2A-PBX1 en paciente pediátrico con leucemia aguda híbrida linfoide b/mieloide / E2A-PBX1 transcript in pediatric patient with acute hybrid lymphoid b/myeloid leukemia

Las leucemias agudas representan un grupo heterogéneo de hemopatías malignas que pueden ser de origen linfoide o mieloide en dependencia del clon celular que da lugar al proceso maligno. Sin embargo, existen casos de leucemias agudas con fenotipo mixto donde coexisten características propias de más de un linaje celular y que se conocen hoy como leucemias agudas de fenotipo mixto. Se presenta el caso de un paciente que se diagnosticó como una leucemia aguda híbrida linfoide B/mieloide mediante citometría de flujo. Se encontró la presencia del gen de fusión E2A-PBX1 que se forma como consecuencia de una traslocación entre los cromosomas 1 y 19. El paciente, un niño de 20 meses de nacido, falleció a los 12 días de iniciados los primeros síntomas clínicos. Se conoce que esta anormalidad cromosómica está asociada a un pronóstico desfavorable, principalmente por la grave afectación del sistema nervioso central como en efecto ocurrió. Hasta donde se alcanzó a revisar, no se encontró un reporte similar en la literatura de una leucemia aguda híbrida linfoide B/mieloide positiva al gen defusión E2A-PBX1(AU)

The acute leukemias are an heterogenous group of malignant hemopathies diseases characterized by excessive proliferation of an inmature cellular clon. Depending of the myeloid or lymphoid origin of such clon, the acute leukemia could be classified in myeloid or lymphoid respectivement. However, there are cases of acute leukemias with mixed phenotype where immunologic markers of more than on elineage are present. In the patient of this report was founded a mixed immunophenotype pattern by flow cytometry and the entity was classified as acute hybrid lymphoid B/ mieloid leukemia. Basedon theinicial diagnostic of acutelymphoidleukemia, the molecular studydiscoveredthepresence of E2A-PBX1 fusion gen. That molecular anomaly is formed as consequence of a traslocation between the1 and 19 chromosomes. The patient, a child of 20 months, died 12 days afte rthe first clynic symptoms begining. E2A-PBX1 fusion gen is associated to unfavorable outcome, mainly because the severe damage at the central nervous system as in fact it occurred. Until it was possible review, no any similar report was founded about a case of acute hybrid lymphoidB/myeloid leukemia positive to the E2A-PBX1 fusion gen(AU)

Haematological profile of patients with mixed-phenotype acute leukaemia from a tertiary care centre of north India.

BACKGROUND & OBJECTIVES: Mixed-phenotype acute leukaemia (MPAL) is a rare neoplasm with no definite treatment protocols and a distinctly poor outcome. Advancement in polychromatic flow cytometry has made its identification easier. This prospective study was designed to identify cases of MPAL and study their clinical presentation and haematological profile in a tertiary care hospital in north India. METHODS: Ethylenediaminetetraacetic acid (EDTA)-anticoagulated bone marrow aspirate samples of patients diagnosed as acute leukaemia (AL) on the basis of morphology were utilized for immunophenotyping. A comprehensive panel of fluorochrome-labelled monoclonal antibodies targeting myeloid, B-cell, T-cell and immaturity markers was utilized. The patients diagnosed to have MPAL, on the basis of the World Health Organization 2008 classification, were selected for further analyses. RESULTS: There were 15 (2.99%) patients with MPAL of the total 501 cases of AL. Seven were children, all males and mean age of 5.08±3.88 yr. Eight were adults, male:female=6:2 and mean age of 21.43±5.74 yr. Eight were diagnosed as B/myeloid and seven were T/myeloid. No association was observed between age and immunophenotype of MPAL. On morphology, 11 were diagnosed as AML and four as ALL, and no specific morphology of blasts was predictive of a MPAL. INTERPRETATION & CONCLUSIONS: MPAL appeared to be a rare neoplasm (2.99% of AL cases). A comprehensive primary panel of monoclonal antibodies should be used to identify this neoplasm known to have a poor outcome.

An unusual case of acute leukemia.

We report the case of a 31 year-old man diagnosed with an atypical acute leukemia difficult to characterize cytologically. The immunophenotyping identified a blastic population co-expressing myeloid, lymphoid B and lymphoid T markers suggesting the diagnosis of either a mixed phenotype acute leukemia (MPAL) or an early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). Because of the poor prognosis linked to these leukemias, the patient benefited from chemotherapy targeting both myeloid and lymphoid components, followed by allogeneic hematopoietic stem cell transplantation. DNA-based techniques analyzing B and T-cell clonality identified partial rearrangements in immunoglobulin and TCR genes, allowing the monitoring of minimal residual disease. This observation highlights the difficulty to classify some atypical cases of acute leukemias. It emphasizes on the complementarity of cytomorphology, immunophenotyping by flow cytometry and molecular techniques in order to promptly characterize and treat these leukemias.

Mixed-phenotype acute leukemia: state-of-the-art of the diagnosis, classification and treatment.

Mixed-phenotype acute leukemia (MPAL) is a heterogeneous group of hematopoietic malignancies in which blasts show markers of multiple developmental lineages and cannot be clearly classified as acute myeloid or lymphoblastic leukemias. Historically, various names and classifications were used for this rare entity accounting for 2-5% of all acute leukemias depending on the diagnostic criterias used. The currently valid classification of myeloid neoplasms and acute leukemia published by the World Health Organization (WHO) in 2016 refers to this group of diseases as MPAL. Because adverse cytogenetic abnormalities are frequently present, MPAL is generally considered a disease with a poor prognosis. Knowledge of its treatment is limited to retrospective analyses of small patient cohorts. So far, no treatment recommendations verified by prospective studies have been published. The reported data suggest that induction therapy for acute lymphoblastic leukemia followed by allogeneic hematopoietic cell transplantation is more effective than induction therapy for acute myeloid leukemia or consolidation chemotherapy. The establishment of cooperative groups and international registries based on the recent WHO criterias are required to ensure further progress in understanding and treatment of MPAL. This review summarizes current knowledge on the diagnosis, classification, prognosis and treatment of MPAL patients.

Co-occurrence of biphenotypic acute leukaemia, glucose 6-phosphate dehydrogenase deficiency and haemoglobin E trait in a single child.

Acute leukaemias occur as the result of clonal expansion subsequent to transformation and arrest at a normal differentiation stage of haematopoietic precursors, which commit to a single lineage, such as myeloid or B-lymphoid or T-lymphoid cells. Biphenotypic acute leukaemia (BAL) constitutes a biologically different group of leukaemia arising from a precursor stem cell and co-expressing more than one lineage specific marker. The present report describes a child with unusual co-occurrence of biphenotypic (B-precursor cell and Myeloid) acute leukaemia, haemoglobin E trait and glucose 6-phosphate dehydrogenase (G6-PD) deficiency. To the best of our knowledge, this constellation of haematological conditions in a single child has never been described before.

Quantitative expression of regulatory and differentiation-related genes in the key steps of human hematopoiesis: The LeukoStage Database.

Differentiation during hematopoiesis leads to the generation of many cell types with specific functions. At various stages of maturation, the cells may change pathologically, leading to diseases including acute leukemias (ALs). Expression levels of regulatory molecules (such as the IKZF, GATA, HOX, FOX, NOTCH and CEBP families, as well as SPI-1/PU1 and PAX5) and lineage-specific molecules (including CD2, CD14, CD79A, and BLNK) may be compared between pathological and physiological cells. Although the key steps of differentiation are known, the available databases focus mainly on fully differentiated cells as a reference. Precursor cells may be a more appropriate reference point for diseases that evolve at immature stages. Therefore, we developed a quantitative real-time polymerase chain reaction (qPCR) array to investigate 90 genes that are characteristic of the lymphoid or myeloid lineages and/or are thought to be involved in their regulation. Using this array, sorted cells of granulocytic, monocytic, T and B lineages were analyzed. For each of these lineages, 3-5 differentiation stages were selected (17 stages total), and cells were sorted from 3 different donors per stage. The qPCR results were compared to similarly processed AL cells of lymphoblastic (n=18) or myeloid (n=6) origins and biphenotypic AL cells of B cell origin with myeloid involvement (n=5). Molecules characteristic of each lineage were found. In addition, cells of a newly discovered switching lymphoblastic AL (swALL) were sorted at various phases during the supposed transdifferentiation from an immature B cell to a monocytic phenotype. As demonstrated previously, gene expression changed along with the immunophenotype. The qPCR data are publicly available in the LeukoStage Database in which gene expression in malignant and non-malignant cells of different lineages can be explored graphically and differentially expressed genes can be identified. In addition, the LeukoStage Database can aid the functional analyses of next-generation sequencing data.

The relationship between clinical feature, complex immunophenotype, chromosome karyotype, and outcome of patients with acute myeloid leukemia in China.

Mixed phenotype acute leukemia (MPAL) is a complex entity expressing both lymphoid and myeloid immunophenotyping. In the present study, 47 MPAL, 60 lymphoid antigen-positive acute myeloid leukemia (Ly(+)AML), and 90 acute myeloid leukemia with common myeloid immunophenotype (Ly(-)AML) patients were investigated. We found that, in MPAL patients, there were high proportions of blast cells in bone marrow and incidence of hepatosplenomegaly, lymphadenopathy, and Philadelphia chromosome. The overall survival (OS) and relapse-free survival (RFS) in MPAL patients were significantly shorter than those in Ly(+)AML and Ly(-)AML. With regard to the patients with normal karyotype only, the OS and RFS of MPAL were significantly lower than those of the Ly(+)AML and Ly(-)AML; but there were no significant differences in OS and RFS among the patients with complex karyotype. The OS rates of 3 groups with complex karyotype were lower than those of patients with normal karyotype. In Cox multivariate analysis, complex karyotype was an independent pejorative factor for both OS and RFS. Therefore, MPAL is confirmed to be a poor-risk disease while Ly(+)AML does not impact prognosis. Complex karyotype is an unfavorable prognosis factor in AML patients with different immunophenotype. Mixed immunophenotype and complex karyotype increase the adverse risk when they coexist.

A Newborn with Congenital Mixed Phenotype Acute Leukemia After In Vitro Fertilization.

Congenital leukemia is a rare disease. The majority of cases of this disease are acute myelogenous leukemia (AML). Congenital acute lymphoblastic leukemia (ALL) is rare and most often is of B cell lineage. Rarely, some cases have been designated biphenotypic or mixed phenotype acute leukemia (MPAL). Herein, we report a preterm newborn referred to us as a result of the appearance of blue-violaceous dermal nodules on her body at birth. She was a twin and the product of an in vitro fertilization (IVF) pregnancy. Physical examination showed jaundice, hepatosplenomegaly, and peripheral facial nerve palsy in addition to dermal nodules. Bone marrow aspiration showed 40% blasts of lymphoid lineage; skin biopsy and its immunohistochemistry revealed myeloblastic infiltration of the dermis. Cytogenetic analysis (46,XX), fluorescence in situ hybridization (FISH) analysis, and cranial magnetic resonance were normal. The patient was diagnosed with congenital MPAL, and an association between IVF and congenital leukemia was suggested.

Long-term survival after transplantation of unrelated donor peripheral blood or bone marrow hematopoietic cells for hematologic malignancy.

We sought to determine whether differences in chronic graft-versus-host disease (GVHD) rates would lead to survival differences by comparing 2463 peripheral blood (PB) and 1713 bone marrow (BM) hematopoietic cell transplant recipients. Patients had acute leukemia, chronic myeloid leukemia (CML), or myelodysplastic syndrome, and they received myeloablative conditioning regimens and calcineurin-inhibitor GVHD prophylaxis. There were no significant differences in long-term survival after transplantation of PB and BM, except for patients in first chronic phase CML. For these patients, the 5-year rate of survival was lower after transplantation of PB compared with transplantation of BM (35% versus 56%, P = .001). Although mortality risks were higher in patients with chronic GVHD after both PB (hazard ratio [HR], 1.58; P < .001) and BM (HR 1.73; P < .001) transplantations, its effect on mortality did not differ by graft type (P = .42). BM is the preferred graft for first chronic phase CML, whereas as either graft is suitable for other leukemias.

Results from a clofarabine-busulfan-containing, reduced-toxicity conditioning regimen prior to allogeneic stem cell transplantation: the phase 2 prospective CLORIC trial.

We prospectively evaluated the safety and efficacy of a clofarabine, intravenous busulfan and antithymocyte globulin-based reduced-toxicity conditioning (CloB2A2) regimen before allogeneic stem cell transplantation. Thirty high-risk patients (median age: 59 years; acute myeloid leukemia n=11, acute lymphoblastic leukemia n=13; myelodysplastic syndrome n=5, bi-phenotypic leukemia n=1) were included in this phase 2 study. At time of their transplant, 20 and seven patients were in first and second complete remission, respectively, while three patients with myelodysplastic syndrome were responding to chemotherapy or who had not been previously treated. The CloB2A2 regimen consisted of clofarabine 30 mg/m(2)/day for 4 days, busulfan 3.2 mg/kg/day for 2 days and antithymocyte globulin 2.5 mg/kg/day for 2 days. The median follow-up was 23 months. Engraftment occurred in all patients. The 1-year overall survival, leukemia-free survival, relapse incidence and non-relapse mortality rates were 63±9%, 57±9%, 40±9%, and 3.3±3%, respectively. Comparing patients with acute myeloid leukemia/myelodysplastic syndrome versus those with acute lymphoblastic leukemia/bi-phenotypic leukemia, the 1-year overall and leukemia-free survival rates were 75±10% versus 50±13%, respectively (P=0.07) and 69±12% versus 43±13%, respectively (P=0.08), while the 1-year relapse incidence was 25±11% versus 57±14%, respectively (P=0.05). The CloB2A2 regimen prior to allogeneic stem cell transplantation is feasible, allowing for full engraftment and low toxicity. Disease control appears to be satisfactory, especially in patients with acute myeloid leukemia/myelodysplastic syndrome. The trial was registered at www.clinicaltrials.gov no. NCT00863148.

Newly diagnosed adult AML and MPAL patients frequently show clonal residual hematopoiesis.

Adult acute myeloid leukemia (AML) is a highly heterogeneous stem cell malignancy characterized by the clonal expansion of immature myeloid precursors. AML may emerge de novo, following other hematopoietic malignancies or after cytotoxic therapy for other disorders. Here, we investigated the clonal vs reactive nature of residual maturing bone marrow cells in 59 newly diagnosed adult AML and mixed phenotype acute leukemia (MPAL) patients as assessed by interphase fluorescence in situ hybridization analysis of AML and myelodysplastic syndrome-associated cytogenetic alterations and/or the pattern of chromosome X inactivation, in females. In addition, we investigated the potential association between the degree of molecular/genetic involvement of hematopoiesis and coexistence of altered immunophenotypes by flow cytometry. Our results indicate that residual maturing neutrophils, monocytes and nucleated red cell precursors from the great majority of newly diagnosed AML and MPAL cases show a clonal pattern of involvement of residual maturing hematopoietic cells, in association with a greater number of altered immunophenotypes. These findings are consistent with the replacement of normal/reactive hematopoiesis by clonal myelopoiesis and/or erythropoiesis in most newly diagnosed AML and MPAL cases, supporting the notion that in most adults presenting with de novo AML, accumulation of blast cells could occur over a pre-existing clonal hematopoiesis.

Targeting of a developmentally regulated epitope of CD43 for the treatment of acute leukemia.

Previously, we developed a JL1 mouse monoclonal antibody that specifically recognizes the leukemic cells of T, B, and myeloid lineages, but not the peripheral blood cells and pluripotent hematopoietic stem cells. Here, we identified that JL1 mAb recognized a specific epitope of human CD43 and validated its potential as an anti-leukemic targeting agent. After the comprehensive screening of JL1 Ag in the human thymocyte cDNA library, multiple fusion gene constructs encoding human CD43 were generated to identify its specific epitope to JL1 antibody. JL1 antibody interacted with a developmentally regulated and non-glycosylated epitope of the human CD43 extracellular domain (AA 73-81, EGSPLWTSI). In an in vivo leukemia model using NOD/SCID mice injected with CCRF-CEM7 cells, JL1 antibody induced effective cytotoxicity in tumor cells and prolonged survival (p < 0.05). Saporin conjugation to JL1 antibody effectively depleted tumor cells in in vitro cytotoxic assays and also prolonged survival in a leukemic mouse model (p < 0.001). These preclinical results further support the therapeutic potential of the JL1 antibody in the management of acute leukemia.

[Immunophenotyping characteristics of biphenotypic acute leukemia and analysis of curative effect].

This study was aimed to investigate the immunophenotyping characteristics of biphenotypic acute leukemia (BAL) and to analyze its curative efficacy. The four-color direct immunofluorescence staining and CD45/SSC gating analysis of flow cytometry were used to detect the cells of bone marrow and peripheral blood of 45 doubtful cases of BAL, and the immunophenotyping was performed according to the European Group for the Immunological Classification of Leukemia (EGIL) score criterion. The results showed that among 45 doubtful cases of BAL, the co-expression of cCD79a and cMPO was observed in 23 cases of My/B-ALL, with highest level of CD19 expression, followed by CD10; the co-expression of cCD3 and cMPO was observed in 18 cases of My/T-ALL, with highest level of CD7 expression, followed by CD5; the co-expression of cCD3 and cCD79a was found in 4 cases of T/B. Out of 45 cases of BAL, 30 cases showed cTdT expression, 25 cases showed CD34 expression, 31 cases showed CD117 expression. The results also indicated that the expression rate of CD33 was higher than that of CD13 in antigen expression of My/B-ALL and My/T-ALL patients. The complete remission (CR) rate of My/B-ALL with My/T-ALL CD34(+) was lower than that of My/B-ALL with CD34(-), the CR rate of My/B-ALL with CD34(+) was lower than that of My/T-ALL with CD34(-). It is concluded that the co-expression of My/B-ALL antigen has been found to be most common, then followed by My/T-All. cCD3, cCD79a, cMPO have important value for diagnosing and identifying of BAL. The flow cytometry with four-color direct immunofluorescence staining is most specific method for diagnosis of BAL. The clinical prognosis of BAL with low cell differentiation is poor.