The 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia.

The World Health Organization (WHO) classification of tumors of the hematopoietic and lymphoid tissues was last updated in 2008. Since then, there have been numerous advances in the identification of unique biomarkers associated with some myeloid neoplasms and acute leukemias, largely derived from gene expression analysis and next-generation sequencing that can significantly improve the diagnostic criteria as well as the prognostic relevance of entities currently included in the WHO classification and that also suggest new entities that should be added. Therefore, there is a clear need for a revision to the current classification. The revisions to the categories of myeloid neoplasms and acute leukemia will be published in a monograph in 2016 and reflect a consensus of opinion of hematopathologists, hematologists, oncologists, and geneticists. The 2016 edition represents a revision of the prior classification rather than an entirely new classification and attempts to incorporate new clinical, prognostic, morphologic, immunophenotypic, and genetic data that have emerged since the last edition. The major changes in the classification and their rationale are presented here.

Myeloid neoplasms in the World Health Organization 2016 classification.

In the 2016 revision of the World Health Organization (WHO) classification, the categories of myeloid neoplasms have not been revised significantly from the 2008 fourth edition. However, recent discovery of molecular abnormalities provides a new perspective regarding the diagnostic and prognostic markers. In myeloproliferative neoplasms, the identification of CALR gene mutation, in addition to the JAK2 and MPL mutations, has impacted the diagnostic criteria. In myelodysplastic syndromes and acute myeloid leukemia, in addition to alterations in the transcription factors and signal transduction pathways, discovery of gene mutations in the epigenetic regulators that are involved in DNA methylation, histone modification, cohesin complex, and RNA splicing, by comprehensive genetic analyses, has improved our understanding of the pathobiology of these diseases. Moreover, recent large-scale sequencing studies have revealed the acquisition of clonal somatic mutations, in the myeloid neoplasm-associated genes of the hematopoietic cells. Such mutations were detected in people with normal blood cell counts, without any apparent disease. Presence of these mutations confers an increased risk for subsequent hematological neoplasms, indicating the concept of clonal hematopoiesis of indeterminate potential. This updated WHO classification incorporates the criteria of new clinical, prognostic, morphologic, immunophenotypic, and genetic findings in myeloid neoplasms.

BCR-ABL-positive acute myeloid leukemia: a new entity? Analysis of clinical and molecular features.

BCR-ABL-positive acute myeloid leukemia (AML) is a rare subtype of AML that is now included as a provisional entity in the 2016 revised WHO classification of myeloid malignancies. Since a clear distinction between de novo BCR-ABL+ AML and chronic myeloid leukemia (CML) blast crisis is challenging in many cases, the existence of de novo BCR-ABL+ AML has been a matter of debate for a long time. However, there is increasing evidence suggesting that BCR-ABL+ AML is in fact a distinct subgroup of AML. In this study, we analyzed all published cases since 1975 as well as cases from our institution in order to present common clinical and molecular features of this rare disease. Our analysis shows that BCR-ABL predominantly occurs in AML-NOS, CBF leukemia, and AML with myelodysplasia-related changes. The most common BCR-ABL transcripts (p190 and p210) are nearly equally distributed. Based on the analysis of published data, we provide a clinical algorithm for the initial differential diagnosis of BCR-ABL+ AML. The prognosis of BCR-ABL+ AML seems to depend on the cytogenetic and/or molecular background rather than on BCR-ABL itself. A therapy with tyrosine kinase inhibitors (TKIs) such as imatinib, dasatinib, or nilotinib is reasonable, but-due to a lack of systematic clinical data-their use cannot be routinely recommended in first-line therapy. Beyond first-line treatment of AML, the use of TKI remains an individual decision, both in combination with intensive chemotherapy and/or as a bridge to allogeneic stem cell transplantation. In each single case, potential benefits have to be weighed against potential risks.

Cytogenetic profiles of 2806 patients with acute myeloid leukemia-a retrospective multicenter nationwide study.

The cytogenetic and molecular data is recognized as the most valuable prognostic factor in acute myeloid leukemia (AML). Our aim was to systemically analyze the cytogenetics of Korean AML patients and to compare the cytogenetic profiles of various races to identify possible geographic heterogeneity. We retrospectively reviewed medical records of 2806 AML patients diagnosed at 11 tertiary teaching hospitals in Korea between January 2007 and December 2011. The most common recurrent chromosomal abnormality was t(8;21) (8.8 %, 238/2717), but t(15;17) showed an almost same number (8.6 %,235/2717). Among de novo AML, the most frequent aberrations were t(15;17), observed in 229 (10.7 %). The most common French-American-British (FAB) classification type was M2 (32.2 %), and recurrent cytogenetic abnormalities correlated with the FAB subtypes. Among 283 secondary AML cases, myelodysplastic syndrome was the most common predisposing factor. About 67.1 % of the secondary AML cases were associated with chromosomal aberrations, and chromosome 7 abnormalities (n = 45, 15.9 %) were most common. The incidence of FLT3 internal tandem duplication mutation was relatively low at 15 %. Our study reports certain similarities and differences in comparison to previous reports. Such discrepancies call for extensive epidemiological studies to clarify the role of genetic as well as geographic heterogeneity in the pathogenesis of AML.

MLL translocations specify a distinct gene expression profile that distinguishes a unique leukemia.

Acute lymphoblastic leukemias carrying a chromosomal translocation involving the mixed-lineage leukemia gene (MLL, ALL1, HRX) have a particularly poor prognosis. Here we show that they have a characteristic, highly distinct gene expression profile that is consistent with an early hematopoietic progenitor expressing select multilineage markers and individual HOX genes. Clustering algorithms reveal that lymphoblastic leukemias with MLL translocations can clearly be separated from conventional acute lymphoblastic and acute myelogenous leukemias. We propose that they constitute a distinct disease, denoted here as MLL, and show that the differences in gene expression are robust enough to classify leukemias correctly as MLL, acute lymphoblastic leukemia or acute myelogenous leukemia. Establishing that MLL is a unique entity is critical, as it mandates the examination of selectively expressed genes for urgently needed molecular targets.

[State of medical care of patients with hematological malignancies in Kyïv].

In the article data are presented about morbidity by oncogematologic pathology - one of the most meaningful of social-economic problems. In Ukraine annually diagnose the to 8 thousand new cases of haemoblastosis. Indexes of morbidity on a 100 thousand population are 5,2; at illness of Hodgkin's lymphoma - 2,5, at plural myeloma - 1,6; at leukemia - 8,1. Morbidity by haematological pathology in Kyiv long time remains high: annually 250 expose patients with malignant lymphnoma, 57 - with myeloma, 190 - with leukemia, from them at 55 % is a sharp form and at 40 % - chronic. The anxiety of doctors causes circumstance that the special treatment is overcome 58,1 % patients by leukemia, 68,6 % - plural myeloma and 77,8 % patients with malignant lymphoma. World experience shows that application of complex methods of therapy allows to prolong life-span 80-90 % patients with Hodgkin's malignant lymphoma on 10, and at 95 % patients by a lymphogranulomatosis - to attain nonrecurrence survival to 5 years.

[microRNA expression in childhood acute granulocytic leukemia and its subtypes].

OBJECTIVE: Recent studies have suggested that there is a close relation between microRNA and acute leukemia (AL). The aim of this study was to investigate and better understand the classification and diagnosis of AL as well as pathogenesis and prognosis of this disease. METHODS: A total of 93 children with AL and and 12 cases of idiopathic thrombocytopenic purpura (as control group) were enrolled in this study. Microarray chip analysis of their bone marrow samples was conducted to evaluate the microRNA profiles. Quantitative real-time PCR was performed for validating the abnormal expression of microRNA. RESULTS: The microRNA expression profiles were different between acute granulocytic leukemia and acute lymphoblastic leukemia and also between the three subtypes (M1, M2 and M3) of acute granulocytic leukemia according to FAB classification based on leukemic cell differentiation. These three subtypes of leukemia could be identified by unsupervised hierarchical cluster analysis of microRNA expression and had specific up-regulation of miR-335, miR-126 and miR-125b, respectively. However, in the M2 and M3 subtypes with positive AML1-ETO and PML-RARα, respectively, which have a better prognosis, the expressions of miR-126 and miR-125b were significantly higher than those with negative AML1-ETO and PML-RARα. Further more, miR-335 and miR-146 were up-regulated in acute granulocytic leukemia observed in this study, which are different from those reported for adult patients. CONCLUSIONS: microRNA cascade may serve as new biomarkers for the classification and diagnosis of pediatric AL. It is also suggested that there might be different pathogenesis and prognosis between AL types related to specific expression and regulation of microRNA.

Eosinophilic myeloid disorders: new classification and novel therapeutic strategies.

PURPOSE OF REVIEW: The aim of this brief review is to evaluate recent developments in the classification and treatment of eosinophilic myeloid disorders in the context of reactive, lymphocyte-variant, and idiopathic eosinophilias. RECENT FINDINGS: The revised 2008 WHO classification recognizes both molecularly defined ('myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR1') and undefined (chronic eosinophilic leukemia, not otherwise specified) eosinophilic myeloid disorders. An increasingly sophisticated understanding of the molecular underpinnings of eosinophilia has translated into rational use of biologically targeted therapies such as imatinib mesylate. Conventional cytotoxics and interferon-alpha still have an established role in treating these diseases. Although studied in idiopathic hypereosinophilic syndrome, the therapeutic niche of anti-interleukin-5 (mepolizumab) and anti-CD52 (alemtuzumab) antibody therapy in eosinophilic myeloid diseases has yet to be established. SUMMARY: Molecular/genetic analysis is now mandatory for the diagnosis, classification, and treatment of eosinophilic myeloid disorders. The finding of rearranged, constitutively activated PDGFRA/B identifies patients who are eminently treatable with tyrosine kinase inhibitors.

Different clinical importance of FLT3 internal tandem duplications in AML according to FAB classification: possible existence of distinct leukemogenesis involving monocyte differentiation pathway.

Impact of FLT3 receptor tyrosine kinase activation via internal tandem duplication (ITD) of the juxtamembrane region on outcome of acute myeloid leukemia (AML) is still controversial. Recent researches reveal a role of FLT3 in monocyte differentiation in hematopoiesis. We analyzed the clinical impact of FLT3 alterations in adult AML patients excluding acute promyelocytic leukemia (APL) who received induction chemotherapy according to morphologic classification. Retrospective review of medical records from three centers in Korea between 1997 and 2007 was performed. Polymerase chain reaction was performed on genomic DNA derived from blood samples of patients before induction chemotherapy for FLT3-ITD detection. We assessed overall survival (OS), first disease-free survival (1-DFS), and response to induction chemotherapy. One hundred eighty-four patients (median age 49.1 years, range 16.0-76.5) with AML excluding APL received induction chemotherapy from three centers. FLT3-ITD was detected in 22 patients. One hundred forty-one patients were below age 60. One hundred seventy-nine patients received induction chemotherapy with cytarabine and idarubicin (AId) regimen. One hundred nineteen patients achieved complete remission (CR) after first induction chemotherapy. FLT3-ITD was not related to achievement of CR. 1-DFS was longer in patients without FLT3-ITD (median 1-DFS 16.5 vs. 8.5 months, p = 0.025). 1-DFS was not different according to FLT3-ITD status in nonmonocyte lineage leukemia (p = 0.355), while 1-DFS was shorter in monocyte lineage leukemia for FLT3-ITD positive patients (20.9 vs. 2.4 months, p < 0.001). FLT3-ITD had no impact on OS except for monocyte lineage, where OS was significantly shorter in FLT3-ITD positive group (39.4 vs. 6.0 months, p = 0.026). Moreover FLT3-ITD was stronger prognostic factors in monocyte lineage AML than risk stratification based on cytogenetics. Status of FLT3-ITD should be analyzed differently in AML patients according to morphologic profile. FLT3-ITD is a predictive and prognostic marker only in monocyte lineage patients. This result suggests an existence of distinct subset of monocyte lineage AML with leukemogenesis involving FLT3 activating pathway.

Molecular classification of cancer: class discovery and class prediction by gene expression monitoring.

Although cancer classification has improved over the past 30 years, there has been no general approach for identifying new cancer classes (class discovery) or for assigning tumors to known classes (class prediction). Here, a generic approach to cancer classification based on gene expression monitoring by DNA microarrays is described and applied to human acute leukemias as a test case. A class discovery procedure automatically discovered the distinction between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) without previous knowledge of these classes. An automatically derived class predictor was able to determine the class of new leukemia cases. The results demonstrate the feasibility of cancer classification based solely on gene expression monitoring and suggest a general strategy for discovering and predicting cancer classes for other types of cancer, independent of previous biological knowledge.

[Classification of myeloid leukemias].

Myeloid leukemia in this series corresponds to the myeloid neoplasms of the 4th WHO classification of pathology and genetics of tumor of haematopoietic and lymphoid tissue. The myeloid neoplasms are composed of six categories, which are 1) myeloproliferative neoplasms (MPN), a new category of 2) myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB or FGFR1, 3) myelodysplastic syndrome (MDS)/MPN, 4) MDS, 5) acute myeloid leukemia (AML) and related precursor neoplasms, and 6) acute leukemias of ambiguous lineage. In MPNs without chronic myelogenous leukemia, the genetic marker of JAK2 V617F is added to the diagnostic criteria for polycythemia vera, essential thrombocythemia and primary myelofibrosis. MDS has the new subtype of refractory cytopenia with unilineage dysplasia composed of refractory anemia, refractory neutropenia and refractory thrombocytopenia. AML with t(9; 11) (p22;q23); MLLT3-MLL, AML with t(6;9) (p23; q34); DEK-NUP214, AML with inv(3) (q21q26.2) or t(3; 3) (q21 ; q26.2); RPN1-EVI1 and AML (megakaryoblastic) with t(1; 22) (p13; q13); RBM15-MKL1 are added to the subtype of AML with recurrent genetic abnormalities, and AML with gene mutations of NPM1 and CEBPA are also added as provisional entities of it. The myeloid neoplasms of the 4th WHO classification are comprehensive and seem to be dynamic by incorporating the results of leukemia researches.

[Fundamental study of blood and bone marrow].

The WHO classification incorporated recent advances of immunology, cytogenetics, and molecular biology, which developed from FAB classification based on cell morphology and cytochemistry. One of the most distinct changes was "AML with recurrent genetic abnormalities." The immunological and cytogenetic studies are required to apply the classification to hematopoietic and lymphoid neoplasms in addition to conventional examinations of the blood and bone marrow. The fundamentals of specimen collection, cell counts, morphologic analysis of blood cells, special stains and other laboratory studies were described in related to the management of myeloid leukemias.

[Chromosome analysis of and genetic testing for myeloid leukemia].

The disease-specific chromosomal abnormalities can be observed in various hematological malignancies, detected by chromosome analysis and/or genetic testing. Genetic testing enables the accurate diagnosis of the type of leukemia resulting from chromosome translocation and hence is useful for the choice of adequate treatment. Furthermore, genetic testing allows the detection of minimal residual disease (MRD) due to its high sensitivity. In recent years, a lot of information has been gained on the evaluation of MRD, e.g., the amount of MRD corresponding to morphological recurrence or requiring the treatment. Thus, the usefulness of MRD quantification at genetic level by real-time PCR has been established. At present, however, there is no standard laboratory procedure for leukemia genetic testing. Here, the problems related to external precision management of this new test are also discussed.

[Clinical problems in the treatment of myeloid leukemia in childhood].

As for childhood AML, intensification of chemotherapy and advance in supportive care have contributed toward the patient survival. In addition to prevent early death, we have to develop a risk classification and appropriate therapies with updated genomics, especially for the intermediate risk group which has much diversity. Also, new treatment strategies utilizing various molecular-targeted therapies are required. For childhood CML, the possibilities of unknown risks which accompanied by life-long imatinib treatment should be considered. Comparing SCT and imatinib, We need to make an original treatment guideline for child CML. Furthermore, according to the increase of long-term survivors, the late adverse effects showed up. We should aim for "full recovery" and hope to have a long-term follow up and feedback system for the survivors.

Flow Plex-A tool for unbiased comprehensive flow cytometry data analysis.

INTRODUCTION: The information content of multiparametric flow cytometry experiments is routinely underexploited given the paucity of adequate tools for unbiased comprehensive data analysis that can be applied successfully and independently by immunologists without computational training. METHODS: We aimed to develop a tool that allows straightforward access to the entire information content of any given flow cytometry panel for immunologists without special computational expertise. We used a data analysis approach which accounts for all mathematically possible combinations of markers in a given panel, coded the algorithm and applied the method to mined and self-generated data sets. RESULTS: We developed Flow Plex, a straightforward computational tool that allows unrestricted access to the information content of a given flow cytometry panel, enables classification of human samples according to distinct immune phenotypes, such as different forms of autoimmune uveitis, acute myeloid leukemia vs "healthy", "old" vs "young", and facilitates the identification of cell populations with potential biologic relevance to states of disease and health. CONCLUSIONS: We provide a tool that allows immunologists and other flow cytometry users with limited bioinformatics skills to extract comprehensive, unbiased information from flow cytometry data sets.

NPM1 mutations and cytoplasmic nucleophosmin are mutually exclusive of recurrent genetic abnormalities: a comparative analysis of 2562 patients with acute myeloid leukemia.

Acute myeloid leukemia carrying NPM1 mutations and cytoplasmic nucleophosmin (NPMc(+) acute myeloid leukemia) represents one-third of adult AML (50-60% of all acute myeloid leukemia with normal karyotype) and shows distinct biological, pathological and clinical features. We confirm in 2562 patients with acute myeloid leukemia our previous observation that NPM1 mutations and cytoplasmic nucleophosmin are mutually exclusive of recurrent genetic abnormalities. Taken together, these findings make NPMc+ acute myeloid leukemia a good candidate for inclusion in the upcoming World Health Organization classification.

Hematopoietic stem cell transplantation for childhood malignancies of myeloid origin.

Myeloid malignancies in children include de novo acute/chronic myeloid leukemia (AML/CML) and secondary malignancy due to genetic predisposition or previous therapy. Generations of clinical trials for childhood myeloid disorders have resulted in improved disease characterization and outcome, and defined therapeutic strategies combining chemotherapy, biologic response modifiers and immunotherapy. With advancement in molecular genetics and the development of sensitive techniques to detect response, residual disease and relapse, therapy can be tailored in a risk-based manner using clinical and biological/molecular parameters and several 'good-risk' myeloid malignancies enjoy high cure rates with targeted therapy. However, hematopoietic stem cell transplant remains the best method of treatment intensification for poor-risk disorders such as relapsed/secondary AML, myelodysplastic syndrome and juvenile myelomonocytic leukemia. Indications for transplant and outcomes of previous clinical studies, and novel transplant strategies designed to improve safety and efficacy of the procedure are reviewed.

Low dose interleukin-2 following intensification therapy with high dose cytarabine for acute myelogenous leukemia in first complete remission.

The most important problem in the therapy of patients with acute myeloid leukemia (AML) is relapse after intensive therapy. We sought to determine if interleukin-2 (low-dose with intermittent boluses) administration could be feasibly administered after standard therapy to potentiate anti-tumor immunity in a fashion analogous to the post-allogeneic stem cell transplant "graft-vs-leukemic" effect. Adults with de novo AML received daunorubicin and cytosine arabinoside induction therapy. Patients achieving complete remission received high dose ara-C (HIDAC) for three courses followed by low dose rIL-2 (Amgen), administered by continuous infusion (450,000 U/m(2)/day) for 10 weeks with intermittent boluses (500,000/U/m(2) over 2 hr) given in weekly intervals starting on Week 4. Of the 32 enrolled patients, 27 achieved CR; 8/11 who received rIL-2 completed therapy. 6/11 are long term survivors (median follow-up, 139 months). rIL-2 was well tolerated and associated with a 5-fold increase in circulating NK-lymphocytes and a 3-fold increase in circulating T-cells. Mononuclear cells from patients receiving rIL-2 exhibited enhanced cytolytic activity in vitro against cryopreserved autologous leukemia cells. This study supports further investigation of immunotherapy in the post-intensive chemotherapy setting in the management of patients with AML.

Prognostic significance of myeloperoxidase expression in childhood acute myeloid leukemia.

BACKGROUND: The percentage of myeloperoxidase (MPO)-positive blast cells is associated with prognosis in adult acute myeloid leukemia (AML), but this association is unsubstantiated in pediatric AML. PROCEDURE: We retrospectively compared cytochemical MPO results with outcome in 154 patients younger than 21 years treated on three consecutive institutional protocols for newly diagnosed AML (1987-2001). Patients with FAB M0 and M7 AML (no MPO expression) or M3 AML (100% MPO expression) and Down's syndrome were excluded. RESULTS: Median MPO expression was higher in FAB M2 subtype than in other subtypes (P < 0.0001) and differed significantly across cytogenetic risk groups (P = 0.002) with highest MPO expression among those with favorable karyotypes. The percentage of MPO-positive blasts was not significantly associated with the probability of complete remission (P = 0.97), event-free survival (P = 0.72), or survival (P = 0.76) in multivariate analyses that accounted for age, FAB subtype, presenting WBC count, cytogenetic and protocol treatment risk group. In analysis limited to patients with intermediate-risk cytogenetics, higher MPO expression appeared to be associated with improved EFS (P = 0.06) but was not associated with remission induction rate (P = 0.16) or overall survival (P = 0.38). CONCLUSIONS: The percentage of MPO-positive blast cells is related to FAB subtype in pediatric AML but has limited prognostic relevance.

In vivo apoptosis of CD8(+) lymphocytes in acute myeloid leukemia patients: involvement of soluble HLA-I and Fas ligand.

In this study, we show that high serum levels of soluble human leukocyte antigens (HLA) class I molecules (sHLA-I, range: 0.7-1.7 micro g/ml) and soluble Fas ligand (FasL, range: 0.4-1.9 ng/ml) are detected in patients with acute myeloid leukemia (AML) at diagnosis, compared with healthy donors (HD) (sHLA-I, range: 0.1-0.6 micro g/ml; sFasL, range: 0.1-0.4 ng/ml). Patients' sera were able to induce transcription and secretion of FasL in CD8(+) T cells, followed by apoptosis in vitro; this apoptosis was inhibited by anti-HLA-I-specific monoclonal antibodies, suggesting that sHLA-I is responsible for cell death. These findings closely relate to the in vivo upregulation of FasL transcription observed in peripheral blood (PB) lymphocytes from AML patients; in the same cells, mRNA for the antiapoptotic proteins Bcl-2 and Bcl-x(L) was downregulated. Interestingly, caspase-8 and caspase-3, both downstream mediators of death receptor-induced apoptosis, were activated in CD8(+) cells of AML patients; one-third of these cells were already apoptotic in vivo, at variance with lymphocytes of HD. These data strongly suggest that in AML, increased levels of sHLA-I molecules may contribute to the elimination of potentially anti-tumor effector cells through a FasL/Fas interaction.