Biphenotypic Acute Leukemia Patients Research Articles

Clinical Characteristics and Outcome of Biphenotypic Acute Leukemia: 10 Cases Report and Literature Review

Background: Based on the cells' antigen differentiation expression patterns, most cases of acute leukemia (AL) are classified as either myeloid or lymphoid lineage. However, there are patients with leukemic blast population that co-express both lymphoid and myeloid characteristics, known as biphenotypic acute leukemia (BAL) or mixed-phenotype acute leukemia (MPAL). BAL is a rare subgroup of acute leukemia with a poor prognosis. Currently, a standard chemotherapy treatment has yet to be established. Aims: This study aims to retrospectively investigate the incidence, pathological characteristics, and clinical outcome of BAL patients from the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, between January, 2014 and June 2019. Methods: From January 2014 to June 2019, the medical records of newly diagnosed BAL based on the EGIL criteria, or ALAL based on the 2008/2016 WHO criteria and who were admitted at the First Affiliated Hospital of Zhengzhou University (Zhengzhou, China) were retrospectively reviewed. The diagnostic workup of BAL was based on initial morphological, cytochemical, and immunophenotypic evaluation of the BM. Using the EGIL scoring system and 2008/2016 WHO criteria, treatment methods and outcome data, including induction chemotherapy, complete remission (CR), relapse, and death, were collected and reviewed. This study was an observational, retrospective, and descriptive study of the clinical aspects of BAL, which was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University. Results: Among a total of 6100 newly diagnosed patients with AL, 10 (0.16%) patients satisfied the definition of BAL based on the EGIL criteria, or MPAL based on the WHO criteria, including 7 males and 3 females. The median age of these patients at diagnosis was 19 years (range 3-67 years). One patient (Pt #1) had extramedullary invasion, including neck, mediastinum (area 8), posterior septal group, left axillary, peritoneal and retroperitoneal lymph nodes. Another patient (Pt #7) had extramedullary invasion with central nervous system leukemia. Immunophenotypic characteristics showed that among 10 BAL patients, 4 cases carried B/Myeloid phenotype, 4 cases carried T/Myeloid phenotype and 2 case carried T/B phenotype. For 8 patients with myeloid lineage differentiation, MPO was positive in 6 (75%), CD13 in 4 (50%), CD33 in 4 (50%), CD38 in 6 (75%), CD58 in 3 (37.5%), CD117 in 4 (50%) patients. In 5 patients with B-lymphoid lineage differentiation, CD19 was positive in 4 (80%), CD79a in 5 (100%) patients. The most frequently T-lymphoid lineage positive markers were CD7 and cCD3, which were positive in 4 of 5 (80%) patients. The stem cell markers HLA-DR and CD34 were both positive in 7 (7/10, 70%) patients, while CD117 was positive in 4 (4/10, 40%) patients. Cytogenetic analysis results showed that 7 of 10 patients had normal karyotypes (Pt#1, 2, 6, 7, 8, 9,10) while the other 3 patients had clonal abnormalities. Pt#4 had 46, xx, t(9;22)(q34;q11) aberration; Pt#6 had 45, XY, -7/46, idem,+8 aberration; and Pt#7 had 45, X,-Y, del(7)q32, t(8,21) (q22;q22) aberration. Two patients (Pt# 3, 5) had RUNX1 gene mutation, one patient (Pt#4) had BCR/ABL fusion gene mutation, and one patient (Pt#9) had JAK1, JAK3, FBXW7 mutation. Six patients received ALL-directed induction therapy (VDLP), whereas two patients received AML-directed induction therapy (MEA and IA regimens). Overall, 4 of 8 (50%) patients with chemotherapy achieved complete remission (CR) after initial induction therapy. In the AML-directed therapy group, 1 of 2 (50%) patients achieved CR. Meanwhile, 3 of 6 (50%) patients achieved CR after ALL-directed induction chemotherapy. Two patients received HSCT after initial CRs, one patient (Pt#7) died two months after transplantation due to the infection, and another patient (Pt#5) is still alive. With an average of 14.3 (4.0-42.0) months follow-up, the median survival time was 7 months. Conclusion: We reported 10 cases of BAL, including 4 cases of B/Myeloid phenotype, 4 cases of T/Myeloid phenotype and 2 case of T/B phenotype. 4 of 8 patients achieved CR (50%) after initial chemotherapy. Although many patients achieved CR after initial chemotherapy, but the relapse rate was very high and the CR rate after relapse was very low. Our results confirmed that BAL is a rare malignancy with a very poor prognosis. Disclosures No relevant conflicts of interest to declare.

Clinical Characteristics And Outcome Of Biphenotypic Acute Leukemia: 10 Case Reports And Literature Review.

BackgroundBiphenotypic acute leukemia (BAL), or mixed-phenotype acute leukemia (MPAL) represents a rare subgroup of acute leukemia which co-expresses markers for either more than one lineage in a homogenous blast population or the coexistence of two blast populations of different lineages. Proper diagnosis and classification of BAL are extremely important for patients’ outcome since BAL usually has a poor prognosis.PurposeThe objective of this study was to identify the incidence of biphenotypic acute leukemia, their clinical characteristics and outcome of BAL patients with the chemotherapy treatment and Hematopoietic Stem Cell Transplantation (HSCT) after initial complete remission.Patients and methodsTen cases of biphenotypic acute leukemia were analyzed for their clinical characteristics, immunological phenotypes, chemotherapy methods for induction initial complete remission and outcome data, including induction chemotherapy, complete remission (CR) and the overall survival time, relapse and death. This study was an observational, retrospective, and descriptive study of the clinical aspects of BAL. Cytogenetics and fusion genes analysis were also done with bone marrow samples using G-banding analysis and karyotyped according to the International System for Human Cytogenetic Nomenclature. The fusion genes’ mutational status was determined by real-time PCR (RT-PCR). Gene mutation analyses were conducted with next-generation sequencing method.ResultsAmong 10 BAL patients, 4 cases carried B/Myeloid phenotype, 4 cases carried T/Myeloid phenotype and 2 cases carried T/B phenotype. Cytogenetic analysis showed that 3 of the 10 cases had clonal abnormalities. Of the four cases of fusion gene aberration, two patients had RUNX1 gene mutation, one patient had BCR/ABL fusion gene mutation, and one patient had JAK1, JAK3, FBXW7 mutation. Overall, 5 of 8 (62.5%) BAL patients with chemotherapy achieved complete remission (CR) after their initial induction therapy. In the AML-directed therapy group, 1 of 2 (50%) patients achieved CR. Meanwhile, 4 of 6 (66.7%) patients achieved CR after ALL-directed induction chemotherapy. Two patients received Hematopoietic Stem Cell Transplantation (HSCT) after initial CRs, one patient died two months after transplantation due to pulmonary infection, and another patient is still alive. With an average of 14.3 (4.0–42.0) months’ follow-ups, the median survival time was 7 months. Although patients achieved CR after initial chemotherapy, the relapse rate was very high and the CR rate after relapse was very low.ConclusionOur results confirmed that BAL is a rare malignancy with a very poor prognosis. Patients with ALL-directed chemotherapy achieved a better CR rate compared to those with AML-directed chemotherapy. Patients should receive HSCT after initial CR whenever it is possible.

PF191 RECLASSIFICATION OF BIPHENOTYPIC ACUTE LEUKEMIA INTO MIXED‐PHENOTYPE ACUTE LEUKEMIA ACCORDING TO WHO CRITERIA REFINES PATIENT CHARACTERIZATION AND PROGNOSIS; DISEASE MARKERS AND IMPACT ON OUTCOME

Background:MPAL is a heterogeneous category in the World Health Organization (WHO) that comprises acute leukemias with discrete admixed populations of myeloid and lymphoid blasts (“bilineal”) or with extensive coexpression of lymphoid and myeloid markers in a single blast population (“biphenotypic”). Mixed phenotype acute leukemia (MPAL) accounts for 2–5% of newly diagnosed acute leukemia. WHO criteria highlight key lineage‐defining markers with particular emphasis on CD19 for B lineage, CD3 for T lineage, and myeloperoxidase (MPO) for myeloid lineage.Aims:Review of classification, biology, clinical features, and treatment approach to MPAL.Methods:We studied retrospectively 1163 consecutive patients diagnosed with acute leukemia at the G. Papanicolaou Hospital, Thessaloniki, Greece, from 1999 until January 2019 subclassified as follows: AML = 854, B‐ALL = 172, T‐ALL = 80, acute undifferentiated leukemia = 9, MPAL/BAL = 44, diagnosed using either the WHO (13/44) or the EGIL (31/44) criteria.Results:Of the 31 patients diagnosed with biphenotypic acute leukemia (BAL) using the EGIL classification 12 did not fulfill the WHO criteria for MPAL. Only 2 B‐Myeloid cases according to the WHO classification did not fulfill EGIL criteria. We reclassified all cases following the WHO criteria and resulted in 32 MPAL cases (2.8% of the cohort; 24/32 B‐Myeloid, 7/32 T‐Myeloid, 1/32 B‐T‐MPAL).Aberrant T‐cell marker expression was seen in 6 patients with B‐Myeloid MPAL, CD7 expression being the most frequent. In T‐Myeloid MPAL, the cytoplasmic CD79a B‐cell marker was aberrantly expressed in 4/7 cases (57%). HLA‐DR was expressed in all MPAL cases. TdT was positive in all Ph+ MPAL, compared to 26% in non‐Ph+ MPAL cases. Seventy‐three percent of the cases were classified as ALL by morphology. Clinical data was available in 25/32 patients; 18 males, 7 females, median age: 32 years (2–79). Median WBC count at presentation was 10.6 × 109/L, hemoglobin 9.3 g/dL, platelets 63 × 109/L, LDH 839 IU/L and marrow blast count 55%. Cytogenetic data available for 29/32 patients were as follows; normal karyotype = 5 (17.2%), t(9;22) translocation = 7 (24.1%), complex karyotype (CK) = 14(48.2%), monosomy 7 = 5 cases (17.2%).Response to treatment and outcome were available for 24 and 29 patients, respectively; 18 received ALL‐type therapy, 3 received AML‐type therapy, 2 a combination of ALL+AML therapy. All Ph+ patients received Tyrosine Kinase Inhibitor (TKI). One died before receiving treatment. ALL‐type treatment induced a response in 13/18 patients (72%), whereas AML‐type in 33.3%; both patients who received combination therapy responded. All refractory patients (7/24) had a complex karyotype. Fourteen patients underwent allogeneic hematopoietic cell transplantation (allo‐HCT). Median overall survival (OS) was 18.7 months; 12 and 27 months for patients with CK and t(9;22) respectively, while the 5‐year survival rate was 12.5%. In contrast, BAL patients classified according to EGIL had median OS 23.3 months.Summary/Conclusion:In our study, reclassification of BAL (EGIL) patients as per WHO, resulted in a more accurate characterization of acute leukemias with mixed phenotypic features. Our study confirms that MPAL/BAL displays a uniformly poor outcome especially in patients with CK. The addition of TKI in the treatment of Ph+ patients probably ameliorates MPAL poor prognosis. Upon validation in larger prospective cohorts, MPAL could be considered as an independent poor risk feature for leukemia patients.

Outcomes of allogeneic hematopoietic cell transplantation in patients with biphenotypic acute leukemia.

The outcomes of allogeneic hematopoietic cell transplantation (HSCT) in patients with biphenotypic acute leukemia (BAL) remain unclear. We retrospectively analyzed the outcomes of HSCT in BAL patients in Japan in comparison to acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) using the registration data from a nationwide database. The data of 90, 5371, and 3301 patients with BAL, AML, and ALL, respectively, were included in the analysis. The median follow-up period was 1481.5 days (range: 0–5556). The 5-year overall survival (OS) of the BAL, AML, and ALL patients were 39.6, 41.8, and 42.0 %, respectively (BAL vs. AML, P = 0.98 BAL vs. ALL, P = 0.77). A multivariate analysis revealed that, in comparison to BAL, AML with a better-risk karyotype was associated with superior OS. An analysis of the prognostic factors of BAL patients showed that OS was significantly longer in patients who were in their first complete remission in comparison to patients who were not in remission. Our data suggest that HSCT is an effective treatment for BAL patients, regardless of the presence of any known poor prognostic factors other than a non-remission status.

Allogeneic Stem Cell Transplantation (Allo-SCT) for De Novo Ph+ Acute Myeloid Leukemia: A Study from the French Society of Bone Marrow Transplantation and Cell Therapies

Introduction: De novo Ph+ acute myeloid leukemia (AML) has recently been described as a distinct AML subtype with a specific genome signature compared to chronic myeloid leukemia (CML). Although Allo-SCT is often proposed as the curative option, the outcome of Ph+ AML treated with Allo-SCT remains unknown in the literature.Methods: Between 2000 and 2012, 19 patients with Ph+ AML who received Allo-SCT were identified in France and compared to 21 patients with Ph+ biphenotypic acute leukemia (BAL) and 52 patients with myeloid blast crisis CML (MBC-CML). Clinical data were prospectively collected though ProMISe (Project Manager Internet Server), an internet-based system shared by all centers of The French Society of Bone Marrow Transplantation and Cell Therapies. The study was approved by local ethical committee.Results: For AML, BAL and MBC-CML patients, the median age per group was respectively 46 (18-67), 36 (18-52) and 36 (18-63) years. Median follow-up was 24 months. Additional cytogenetic abnormality was not different between the 3 groups. The MBC-CML group had a lower rate of induction therapy before Allo-SCT compared to the 2 other groups and a lower rate of remission status before transplant (p<0.0001). However tyrosine-kinase inhibitor (TKI) exposure during induction was similar in each arm. A myelo-ablative conditioning regimen was used in 72% of cases without difference in each group. However the Ph+ BAL group received significantly more TBI-cyclophosphamide conditioning regimen compared to the Ph+ AML and MBC-CML groups (p<0.03). No difference was observed between the 3 groups concerning graft source or the use of antithymocyte globulin (ATG). Acute graft-versus-host disease (aGVHD) with a grade≥2 was observed respectively in 37%, 19% and 32% of the Ph+ AML, BAL and MBC-CML groups. Chronic GVHD incidence was 42%, 24% and 27% in the 3 groups. Relapse I ncidence was 28%, 29% and 49% in the 3 groups. Two-year overall survival probability for Ph+ AML, BAL and MBC-CML was 65.5% (45.4-79.7), 58.3% (32.7-71.4), 38.3% (95% CI: 26.2-50.3), respectively (p=0.016, log-rank test, Figure 1). Two-year cumulative incidence of non-relapse mortality (NRM) was 17.7% (0.07-0.4) for Ph+ AML, 25.96 % (0.12-0.49) for Ph+ BAL and 33.2% (0.21-0.49) for the MBC-CML group. In univariate analysis, remission status and type of disease (Ph+ AML) were predictive factors for a better survival rate. The onset of GVHD was also predictive of a better overall survival (HR 0.43 [0.23-0.78], p=0.006).Conclusion: Limited data are available on de novo Ph+ AML. This study showed a promising 65% two-years overall survival in Ph+ AML subtype in comparison with others Ph+ acute leukemia. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Clinical study on role of CD34 in patients with Biphenotypic acute leukemia

This study was aimed to explore the expression of CD34 in patients with biphenotypic acute leukemia (BAL) and its relation with the prognosis of BAL. The flow cytometry was used to detect leukemia-associated antigen. The used monoclonal antibodys (McAb) included CD10, CD19 and CD34 for B lymphocyte lineage, CD2, CD3 and CD5 for T lymohocyte lineage, MPO, CD13 and CD33 for myeloid lineage. The finally results were respectively analyzed. The results indicated that 9 out of 216 cases of leukemia was diagnosed as BAL (4.2%). Among 9 cases of BAL, 6 cases showed the common expression of myeloid and T lymohocyte lineages (66.7%), 3 cases showed the common expression of myeloid and B lymohocyte lineages (33.3%). 4 cases of BAL displayed CD34 positive expression (44.4%). As compared with acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL), the BAL patients showed higher CD34 positive expression (P < 0.05). It is concluded that the BAL patients show a poor prognosis, as compared with AML or ALL patients. The therapeutic effect of BAL may negatively correlate with the CD34 positive expression.

Gene expression profiling of the DNMT3A R882 mutation in acute leukemia

DNA methyltransferase 3A (DNMT3A) is one of two human de novo DNA methyltransferases essential for the regulation of gene expression. DNMT3A mutations and deletions have been previously observed in acute myeloid leukemia (AML), myelodysplastic sydromes and myeloproliferative neoplasms. However, the involvement of DNMT3A in acute lymphoblastic leukemia (ALL) has rarely been reported. In the present study, PCR and direct sequencing was performed to analyze mutations of DNMT3A amino acid residue 882 in 99 acute leukemia patients, including 57 AML patients, 41 ALL patients and a single biphenotypic acute leukemia (BAL) patient. DNMT3A expression was detected in mono-nuclear cells of the bone marrow in these patients and in normal individuals using real-time quantitative polymerase chain reaction, and 17.5% (10/57) of AML patients were found to exhibit DNMT3A mutations. Four missense mutations were observed in the DNMT3A-mutated AML patients, including R882 mutations and a novel single nucleotide polymorphism resulting in the M880V amino acid substitution. However, the ALL and BAL patients were not found to exhibit DNMT3A mutations. The DNMT3A expression levels in the AML patients were significantly higher compared with those of the ALL patients or normal controls. The reduced expression levels of DNMT3A were associated with a significantly lower complete remission rate in the AML patients. However, in the ALL patients, no statistical significance was identified. The results of the present study indicate that DNMT3A may play varying roles in the regulation of DNA methylation in AML and ALL.

Acute leukemias of ambiguous lineage in adults: molecular and clinical characterization

Acute leukemias of ambiguous lineage represent a heterogeneous group of rare, poorly characterized leukemias with adverse outcome. No larger studies have yet performed a combined approach of molecular and clinical characterization of acute undifferentiated leukemia (AUL) and biphenotypic acute leukemia (BAL) in adults. Here we describe 16 adults with AUL and 26 with BAL and performed mutational as well as expression studies of genes with prognostic impact in acute leukemia (BAALC, ERG, MN1, WT1, and IGFBP7). AUL showed overexpression of these genes compared to T-lymphoblastic leukemia (T-ALL), B-precursor ALL, and to acute myeloid leukemia (AML). Genotype alterations were not detectable in AUL. BAL samples were characterized by frequent WT1 mutations (18 %) and BCR-ABL translocations (30 %). ALL-based treatment protocols induced complete remissions in 40 % and AML-like therapies in 22 % of AUL/BAL patients. The outcome in both groups was very poor; a long-term survival was only observed in patients undergoing allogeneic stem cell transplantation (SCT). Our findings indicate that AUL and BAL share important molecular and high-risk features of both myeloid and lymphoid leukemias. BAL patients exhibited genetic alterations, which can be targeted therapeutically. Importantly, ALL therapy might be more effective than AML protocols and AUL/BAL patients should be considered for allogeneic SCT.

Incidence of Philadelphia-chromosome in acute myelogenous leukemia and biphenotypic acute leukemia patients: And its role in their outcome

Background Philadelphia-chromosome positive acute myeloid leukemia (Ph+ AML) is a rare entity and patient prognosis is poor, with short median survival. Biphenotypic acute leukemia (BAL) is a rare disorder that is difficult to diagnose and it displays features of both myeloid and lymphoid lineage. The aim of this study was to highlight the incidence of Philadelphia chromosome and its presence in cases of acute myeloid and biphenotypic leukemia and determine its role in the outcome of these leukemias. Subjects and methods This study examined 464 subjects with newly diagnosed acute myeloid leukemia: 312 were males and 152 were females. All individuals were subjected to immunophenotyping and conventional karyotyping. FISH was used in failed cases of conventional cytogenetics analysis to quantify disease and to prove positive BCR-ABL fusion gene. Results the incidence of Ph+ chromosome was found to be higher in BAL (38.4%) than in AML (1.99%). There was statistically significant difference according to the age and the median survival time between the two groups. Conclusion Detection of specific chimeric transcripts in AML and BAL at the time of diagnosis was crucial since it plays an important role for accurate risk stratification and treatment management.

Molecular Characterization of Acute Undifferentiated and Biphenotypic Leukemia

AbstractAbstract 1692 Background:Acute leukemias of ambiguous lineage account for only 3–5% of all cases of acute leukemia and represent a heterogeneous group of rare, poorly characterized leukemia with adverse outcome. The aim of this study was to further molecularly characterize this rare subtype to gain insights into the pathogenesis of acute undifferentiated leukemia (AUL) and biphenotypic acute leukemia (BAL). These molecular insights may then lead to targeted treatment strategies for specific molecular subgroups. Design and Methods:The European Group for Immunologic Classification of Leukemia (EGIL) defines BAL as a single blast population with co-expression of myeloid- and lymphoid-associated antigens according to a scoring system. Cases without expression of lineage-specific antigens are designated as AUL. Based on the EGIL scoring system, we identified 11 and 20 adults with newly diagnosed AUL and BAL, respectively. In all samples, flow cytometry was performed using a panel of monoclonal antibodies for precursor cells (CD34, TdT), lymphoid-associated antigens, including surface and cytoplasmic antigens (CD79a, CD22, IgM, CD19, CD20, CD10, CD24, CD3, TCR, CD2, CD5, CD8, CD7, CD1a), and myeloid-associated antigens including myeloperoxidase, CD13, CD33, CD65s, CD117, CD14, CD15, CD64. In order to further molecularly characterize AUL and BAL, samples were studied for expression and genotype alterations of candidate genes with prognostic impact or with relevance in the pathogenesis of acute leukemias. The mRNA expression levels of BAALC, IGFBP7, MN1, and WT1 were determined by quantitative real-time PCR. In addition, samples were studied for WT1 mutations in exons 7 and 9, for FLT3 mutations [internal tandem duplications (ITD) and mutations in the tyrosine kinase domain (TKD835)], as well as for BCR-ABL (breakpoints: e1/a2; b3/a2; b2/a2) and MLL-AF4 rearrangements. Results were than compared to data generated from acute myeloid leukemia (AML; n = 75), acute T-lymphoblastic leukemia (T-ALL; n = 242) and B-precursor ALL (n = 368) patients. Results:AUL patients were characterized by a specific gene expression pattern. In particular, in AUL over-expression was shown for IGFBP7 (P = 0.01) and MN1 (P = 0.04) compared to BAL; for BAALC (P = 0.001), IGFBP7 (P = 0.0001) and MN1 (P = 0.02) compared to T-ALL; for BAALC (P = 0.02) and IGFBP7 (P = 0.001) compared to AML; as well as for IGFBP7 (P = 0.0001) compared to B-precursor ALL. Genotype alterations (WT1, FLT3, BCR-ABL, MLL-AF4) were not detectable in AUL samples.The majority of BAL cases expressed either T-lineage plus myeloid antigens (n = 9; 45%) or B-lineage plus myeloid markers (n = 9; 45%), while co-expression of T/B lymphoid antigens was only seen in 2 samples of BAL. Cell surface expression of CD34 (≥ 20%) was most frequently found in BAL (17 of 20 cases; 85%). Gene expression studies revealed over-expression of BAALC and IGFBP7 in BAL compared to T-ALL, AML and B-precursor ALL, but less pronounced as shown for AUL. Moreover, BAL samples were characterized by frequent WT1 mutations in exon 7 (sufficient DNA was available in 14 samples of which 4 had WT1 mutations; 29%). In contrast, WT1 mutations were only found in 8% of T-ALL and have previously been reported in about 10% of AML patients with normal cytogenetics (Paschka et al, 2008). In concordance with published data, the BCR-ABL fusion gene was detected in 32% of BAL samples (19 samples studied of which 9 were positive for BCR-ABL). MLL-AF4 translocations and FLT3 mutations were not detectable in this BAL cohort. Conclusion:Here we present a comprehensive molecular study investigating mRNA expression and genotype alterations in the poorly characterized subgroup of acute leukemias with ambiguous or lacking lineage commitment. We show that AUL and BAL patients share important prognostic features of both myeloid and lymphoid leukemias. Over-expression of stem cell associated genes (BAALC and IGFBP7) and genes associated with an adverse prognosis (BAALC and MN1) was most prominent in AUL. As lineage-directed therapies are likely ineffective for these high-risk patients and the fact that AUL lack known specific molecular targets, further studies are warranted to unravel molecular aberrations, which might allow the development of more specific therapies. BAL patients however, were characterized by genetic aberrations including BCR-ABL rearrangements and WT1 mutations, which may imply targeted therapy options. Disclosures:No relevant conflicts of interest to declare.

What is the optimal treatment for biphenotypic acute leukemia?

We read with great interest the paper written by Xu et al .[1][1] about a comprehensive investigation in clinical and biological characteristics of adult biphenotypic acute leukemia (BAL) in China. We agree that the prognosis of BAL patients is poor when compared with de novo acute myeloid leukemia

Outcomes of CAG Regimen for Refractory Biphenotypic Acute Leukemia Patients.

Abstract 4111 ObjectiveBiphenotypic acute leukemia (BAL) involves both myeloid and lymphoid cells, and there is lack of uniformity in treatment at present. Optimal approach for therapy of BAL is unknown, and BAL usually becomes refractory to conventional chemotherapy. It was found that CAG regimen [low-dose cytosine arabinoside (Ara-C) plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor (G-CSF)] is effective for both myeloid leukemia and refractory acute lymphoblastic leukemia. To explore the efficiency of CAG regimen for refractory BAL, 12 BAL patients who were failed to daunorubicin/mitoxantrone, cytosine arabinoside, vincristine, prednisone (D/MAOP) regimen, were treated by CAG. 8 were males and 4 was female, with ages ranging from 20 to 43 years (median=34 years). Immunophenotype of B lymphoid lineage/myeloid lineage showed in 8 patients, and T lymphoid lineage/myeloid lineage showed in 4 patients. The patients whose blast cells did not decrease 50% after induction regimen with lymphoid and/or myeloid drugs were defined as refractory cases. Methods12 refractory BAL patients were treated by CAG regimen (cytosine arabinoside 10 mg/m2 subcutaneously every 12 hours, day 1-14; aclarubicin 5-7 mg/m2 intravenously daily, day 1-8; and concurrent use of granulocyte colony-stimulating factor 200μg·m-2·d-1 subcutaneously) from November 2002 to April 2009. The efficacy of the regimen was evaluated by response rate, and the side-effects was also measured. ResultsThe major chemotherapy toxicity was bone marrow depression, mainly showing as pancytopenia. Median duration of absolute neutrophil count (ANC)<0.50×109/L and of platelet (PLT) count<20×109/L was 13 (range, 1-17) days and 1 day (range, 0-5 days), respectively. Median transfusion of red cells and PLT was 4 (range, 1.5-12) U and 20 (range, 0-40) U, respectively.Besides bone marrow depression, other side-effects such as infection, bleeding, nausea and vomiting also occurred during therapy. According to chemotherapy toxicity assessment of WHO, there were 7 patients confronting infection, among whom only 2 patient occurred III-‡W infection. No serious nausea vomiting or hepatic function damage happened. Disclosures:No relevant conflicts of interest to declare.

CHILDHOOD Biphenotypic ACUTE LEUKEMIA with High Incidence of Basophilic Differentiation: The CONTRIBUTION of Ultrastructural Methods to Diagnosis.

Abstract 4698The diagnosis of Biphenotypic Acute Leukemia (BAL) is still a challenge in clinical hematology. In spite of the use of the score formulation of the European Group for the Immunological Classification of Leukemias (EGIL) there are still cases difficult to define. We assessed the contribution of ultrastructural morphology and cytochemistry to the diagnosis of BAL in pediatric leukemic patients. Twenty six patients diagnosed at Schneider Children's Medical Center of Israel between the years 1989 to 2004 have been classified as BAL in a retrospective analysis evaluated by various combinations of light-microscopy (LM) morphology, immunophenotype flow-cytometry, cytogenetics and electron-microscopy (EM) including myeloperoxidase (MPO) and platelet peroxidase (PPO) reaction. The identification of myeloid features by EM was based on the presence of 1) MPO positive granules and MPO reactivity in the nuclear membrane, profiles of endoplasmic reticulum (ER) and in the membranes of the Golgi system; 2) PPO reaction in the nuclear membrane and profiles of ER, and 3) the presence of primary basophilic granules in the cytoplasm of the blasts. The EGIL scoring system has been used with the addition of the ultrastructural findings for the definition of BAL. In 24 cases the morphologic appearance and cytochemistry by LM of the leukemic cells were that of undifferentiated blasts. By cytogenetic evaluation abnormal karyotypes were detected in 16 patients, normal in 4 and unknown in 6 patients. Out of 26 patients 15 had the combination of T-ALL with myeloid phenotype and 11 had the B-lineage with myeloid features. Unexpectedly the blasts of 9 of the 26 BAL patients had basophilic differentiation as indicated by the presence of typical primary basophilic granules with MPO reactivity in a scattered pattern as previously reported in basophylic leukemia. Interestingly 7 of these 9 cases had a T lymphoid component. By contrast among 15 patients who had FAB M0, 9 had the B lineage markers. The remaining 2 patients had M1 and M7 features with T lymphoid phenotype. The contribution of EM studies enabled to establish the diagnosis of BAL in 11 out of 26 patients, in other 6 patients it allowed for the refinement of the AML subgroup such as basophilic leukemia and in the remaining 9 patients EM confirmed the diagnosis of BAL as defined by flow cytometry. ConclusionsOur study identified a subgroup of children with acute leukemia in whom BAL could be suggested only by the addition of ultrastructural studies. EM could further refine and confirm the diagnosis of BAL in all the other cases. Of interest is the high incidence of basophylic differentiation among BAL pediatric patients, and its association with T lymphoid phenotype. Disclosures:No relevant conflicts of interest to declare.

Outcomes of CAG Regimen for Refractory Biphenotypic Acute Leukemia Patients

To evaluated the efficiency of low-dose cytosine arabinoside plus aclarubicin with concurrent administration of granulocyte colony-stimulating factor (CAG) regimen for refractory biphenotypic acute leukemia (BAL). We treated 5 refractory BAL patients by CAG regimen (10 mg x m(-2) cytosine arabinoside subcutaneously administrated every 12 hours, day 1-14; 5-7 mg x m(-2) aclarubicin intravenously administrated daily, day 1-8; and concurrently used 200 microg x m(-2) x d(-1) granulocyte colony-stimulating factor subcutaneously) from November 2002 to April 2007. The efficacy of the regimen was evaluated by response rate, and the side effects were also measured. The complete remission rate was 80%, median duration of absolute neutrophil count < 5.0 x 10(8)/L and platelet count < 2.0 x 10(10)/L was day 13 and day 1, respectively; and the infection rate was low (III-IV infection rate, 20.00%). CAG regimen as remission induction chemotherapy for BAL patients is effective with a high remission rate and low toxicity.

Stem cell transplant in the treatment of childhood biphenotypic acute leukemia

Many studies have found that biphenotypic acute leukemia (BAL) is associated with a poor outcome. We retrospectively reviewed the medical records and analyzed clinicopathological data on 25 children with BAL, and correlated outcomes with prognostic factors. BAL constituted 4.4% of all acute childhood leukemia cases. In terms of immunophenotype, 14 patients had leukemia with myeloid plus B-lymphoid (M + B) marker, 7 with myeloid plus T-lymphoid (M + T) marker, and 4 with myeloid plus B-lymphoid and T-lymphoid (M + B + T) markers. Overall survival was superior in patients with the M + B immunophenotype (P = 0.004). Hematopoietic stem cell transplantation (HSCT) did not improve either overall survival or event-free survival compared to chemotherapy alone (hazard ratio 0.98, 95% CI 0.35-2.76, P = 0.966; hazard ratio 1.07, 95% CI 0.41-2.78, P = 0.88). Each of four patients with high-hyperdiploidy (>50 chromosomes) displayed a good treatment response and long-term overall survival even though these patients were treated with chemotherapy alone. Treatment outcomes in childhood BAL patients differed by immunophenotype and cytogenetics. HSCT did not offer a significantly greater survival advantage compared to chemotherapy. While these data suggest that treatment should be individualized and stratified according to biologic characteristics and prognostic factors in BAL, prospective trial data are still needed.

Clinical and biological characteristics of adult biphenotypic acute leukemia in comparison with that of acute myeloid leukemia and acute lymphoblastic leukemia: a case series of a Chinese population

Biphenotypic acute leukemia is a rare disorder that is difficult to diagnose. It displays features of both myeloid and lymphoid lineage. There is still a lack of studies in biphenotypic acute leukemia in a Chinese population. We present here a comprehensive investigation of the clinical and biological characteristics, and outcome of biphenotypic acute leukemia in our hospital in over a seven year period. We retrospectively analyzed 452 adult acute leukemia patients diagnosed according to French-American-British (FAB) classification and biphenotypic acute leukemia diagnosed according to European Group for the Immunological Characterization of Leukemias (EGIL) classification, respectively. Biological characteristics, response to treatment, and outcome were examined in biphenotypic acute leukemia patients and compared with that in acute myeloid leukemia and acute lymphoblastic leukemia patients with complete follow-up profiles diagnosed in the same period. Of 452 acute leukemia patients, 21 cases (4.6%) were diagnosed as biphenotypic acute leukemia. Among them, 14 (66.7%) were B lymphoid and myeloid, 5 (23.8%) were T lymphoid and myeloid, one (4.8%) was T/B lymphoid and one (4.8%) was trilineage differentiation. When compared with acute myeloid leukemia and acute lymphoblastic leukemia, patients with biphenotypic acute leukemia showed significantly higher incidence of CD34 antigen expression, unfavorable karyotypes, and extramedullary infiltration (p<0.05). In this cohort of patients with biphenotypic acute leukemia, t(9;22) was the most common abnormality in chromosome structure. The median disease-free survival and overall survival in biphenotypic acute leukemia patients was five months and ten months, respectively, significantly shorter than those in acute myeloid leukemia and acute lymphoblastic leukemia patients (p<0.05). The prognosis of biphenotypic acute leukemia patients is poor when compared with de novo acute myeloid leukemia or acute lymphoblastic leukemia. Biphenotypic acute leukemia patients showed a much higher incidence of CD34 antigen expression, complex abnormal karyotype, extramedullary infiltration, relapse, and resistance to therapy after relapse.

T(9;22) with 5'ABL1 Deletion and t(6;19) in Biphenotypic Acute Leukemia

Biphenotypic acute leukemia (BAL) is a rare type of leukemia, comprises 4% of all acute leukemias. It is more common in adults and the clinical features, as related to marrow dysfunction, are similar to those found in other patients with acute leukemia. BAL commonly shows a dimorphic blast population with, one resembling lymphoblasts and the other resembling myeloblasts. The majority of BAL patients express B-lymphoid and myeloid markers. BAL can be diagnosed by morphologic studies and by a comprehensive panel of immunological markers, as well as cytogenetic/molecular studies, such as fluorescence in situ hybridization (FISH) and reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, its prognosis is relatively poor. We present here a 27 year-old female patient who showed lymphoblasts and myeloblasts on her marrow studies and these cells were positive for myeloid and B-lymphoid markers on the immunophenotypic studies. Chromosome analysis revealed 46,XX,t(6;19)(p23;p13.1),t(9;22)(q34;q11.2). A major (b3a2) type of BCR-ABL1 mRNA transcript was detected by RT-PCR, and a 5' ABL1 deletion was identified by FISH.

Prognostic Implications of the Immunophenotype in Biphenotypic Acute Leukemia.

Biphenotypic acute leukemia (BAL) is a rare yet defined type of acute leukemia. We investigated the incidence, clinicopathologic characteristics, and clinical outcomes of BAL in Korean adults. The present study retrospectively analyzed clinicopathological and clinical data from 43 adult patients with BAL, defined using the EGIL scoring system, from 11 Korean institutes. The incidence of BAL was 2.1% among acute leukemias; 2.3% in male and 1.9% in female. Median age of 43 BAL patients, 25 males and 18 females, was 38 years (range, 16–74). The immunophenotype was myeloid/B-lymphoid (M+B) in 31 (72.1%), myeloid/T-lymphoid (M+T) in 10 (23.3%), and B/T-lymphoid (B+T) and myeloid/B/T-lymphoid (M+B+T) in one (2.3%) each. 37 patients had the results of cytogenetic analyses and Ph chromosome (n=14, 37.8%) was the single most common abnormal finding. Intensive induction chemotherapy was given in 36 of 43 patients: AML-type in 13 (36.1%), ALL-type in 8 (22.2%), and combined type in 15 (41.7%). Complete remission (CR) was induced in 29 patients (80.6%). The CR rate was significantly lower in M+T (5 of 9, 55.6%) than M+B (22 of 25, 88.0%) (P=0.039). Other unfavorable factors for CR were absence of CD19 (P=0.029) or CD20 (P=0.046), and presence of CD2 (P=0.040). The CR rates were not significantly different according to cytogenetic finding or type of induction chemotherapy. After median follow-up duration of 712 days among surviving patients, 11 patients relapsed with median relapse-free survival (RFS) of 3.08 years and 4-y RFS of 38.3% and 18 patients died with median overall survival (OS) of 2.49 years and 4-y OS of 30.1%. Multivariate analysis showed that high leukocyte counts (≥ 30,000/μl) at diagnosis (OR, 5.922; 95% CI, 1.379–25.429; P=0.017) was an independent unfavorable prognostic factor for RFS, and high leukocyte counts at diagnosis (OR, 9.348; 95% CI, 3.014–28.993; P<0.001) and M+T phenotype (OR, 3.259; 95% CI, 1.136–9.344; P=0.028) were independent unfavorable prognostic factors for OS. In summary, BAL was found in 2.1% of adult acute leukemias and M+T phenotype showed significantly poorer response to induction chemotherapy and inferior overall survival compared to M+B phenotype.

IgH and TCRgamma Gene Rearrangements, Cyclin A1 and HOXA9 Gene Expression in Biphenotypic Acute Leukemias.

Biphenotypic acute leukemia (BAL) represents a rare type of acute leukemia (AL) with the reported incidence of 4.0–8.5% and poor response to treatment. In adult BAL, poor prognosis is related to unfavorable cytogenetics and P-glycoprotein over-expression (Legrand et al, Br J Haematol 1998; 100:147–55). It is presumed that better knowledge of its biological features could improve the classification and clinical management of this rare type of acute leukemia. Due to paucity of data regarding biological parameters of BAL, in this study we have analyzed the rearrangements of immunoglobulin heavy chain (IgH) and T-cell receptor g (TCRg) genes, expression of cyclin A1 (CycA1) and HOXA9 genes as well as in vitro growth of 10 de novo BALs and compared them with 15 AML and 15 ALL, respectively. The diagnosis of BAL was established according to EGIL criteria. BAL represented 4.3% of adult and 3.0% of pediatric patients with de novo AL referred to our institution during the 1999–2003 period. Of 10 BALs studied, lymphoid BAL (L2) was identified in 3 children, myeloid BAL (M1 and M5) was identified in 3 adults and one child, BAL of undifferentiated cytomorphology (AUL) in 2 adult patients, whereas one 5-month-old child presented with two separate blast cell populations (L1+M5b, bilineal BAL). With regard to immunophenotype, the group of BAL patients was also heterogeneous: 8/10 expressed the combination of myeloid and B-lymphoid antigens and 2/10 expressed myeloid and T-lymphoid antigens. The majority of BAL expressed CD34 (89%). Cytogenetic analysis was obtained in 7 BAL patients, of whom 3 showed chromosome 11 aberrations and 1 had Ph+ chromosome. Our results indicate that IgH and TCRγ gene rearrangements correlated well with lymphoid BAL morphology. Interestingly, the majority of lymphoid BAL showed oligoclonal amplification of antigen-receptor genes, indicating the coexistence of several malignant clones at the time of presentation. The expression of CycA1 correlated well with myeloid and undifferentiated BAL morphology. In contrast, the expression of HOXA9, a marker associated with myeloid cell lineage, showed no strong correlation with BAL morphology. BAL showed almost equal in vitro growth in three different serum-free culture conditions (no addition of GF, addition of IL-7 and FL or GM-CSF and FL), indicating that their growth was less dependent on the addition of exogenous GFs. Finally, in vitro growth of blasts during a 7-day culture showed autonomous cell growth in 3/10 AML and 3/8 myeloid BAL samples tested, but not in any of the AL with lymphoid features. Finally, further studies are needed to confirm these findings and to extend research to a broader spectrum of cell markers aiming to give a better definition of this rare group of AL.