WHO Classification Of Myeloid Neoplasms Research Articles

Frequency of polycythemia in individuals with normal complete blood cell counts according to the new 2016 WHO classification of myeloid neoplasms.

Polycythemia vera (PV) is a disorder characterized by clonal proliferation of myeloid cells and increased red blood cell mass. Recently, the revised 2016 WHO classification of myeloid neoplasms decreased the threshold levels of hemoglobin and hematocrit for the diagnosis of PV. However, the new proposed cutoffs have remarkable overlap with the normal reference values reported and the clinical impact of these new cutoffs has not been widely assessed in the general population. We retrospectively examined 248839 patients with presumptively normal complete blood cell results, consecutively obtained in an outpatient setting. The proportion of men with Hb >165g/L was 5.99%, Hct>49% was 2.4%, and Hb >165g/dL or Hct>49% was 6.48%, while the proportion of women with Hb >160g/L was 0.22%, Hct>48% was 0.11%, and Hb >160g/L or Hct>48% was 0.28%. The isolated use of the proposed Hb/Hct levels as a definer of polycythemia may lead to a substantial increase in unnecessary diagnostic tests. In cases with borderline levels of hemoglobin, the diagnostic workup of PV should only be indicated in the presence of clinical and/or laboratorial features associated with MPN.

Genomics of Acute Myeloid Leukemia Diagnosis and Pathways.

In recent years, our understanding of the molecular pathogenesis of myeloid neoplasms, including acute myeloid leukemia (AML), has been greatly advanced by genomics discovery studies that use novel high-throughput sequencing techniques. AML, similar to most other cancers, is characterized by multiple somatically acquired mutations that affect genes of different functional categories, a complex clonal architecture, and disease evolution over time. Patterns of mutations seem to follow specific and temporally ordered trajectories. Mutations in genes encoding epigenetic modifiers, such as DNMT3A, ASXL1, TET2, IDH1, and IDH2, are commonly acquired early and are present in the founding clone. The same genes are frequently found to be mutated in elderly individuals along with clonal expansion of hematopoiesis that confers an increased risk for the development of hematologic cancers. Furthermore, such mutations may persist after therapy, lead to clonal expansion during hematologic remission, and eventually lead to relapsed disease. In contrast, mutations involving NPM1 or signaling molecules (eg, FLT3, RAS) typically are secondary events that occur later during leukemogenesis. Genetic data are now being used to inform disease classification, risk stratification, and clinical care of patients. Two new provisional entities, AML with mutated RUNX1 and AML with BCR- ABL1, have been included in the current update of the WHO classification of myeloid neoplasms and AML, and mutations in three genes- RUNX1, ASXL1, and TP53-have been added in the risk stratification of the 2017 European LeukemiaNet recommendations for AML. Integrated evaluation of baseline genetics and assessment of minimal residual disease are expected to further improve risk stratification and selection of postremission therapy. Finally, the identification of disease alleles will guide the development and use of novel molecularly targeted therapies.

How We Treat Patients With Polycythemia Vera

How We Treat Patients With Polycythemia Vera

Biological Predictive Scoring System in Low Risk Myelodysplastic Syndromes (LR-MDS)

BackgroundMyelodysplastic syndrome (MDS) is a pre-leukemia disease affecting the erythroid, myeloid and megakaryocytic bone marrow production. MDS patients are classified according to the WHO classification of myeloid neoplasms. During the past 15 years management of MDS patients has been stratified according to the International Prognostic Scoring System (IPSS) risk score. Recently a revised version of IPSS has been introduced (IPSS-R). One quarter of LR-MDS in this new IPSS-R were reclassified as having a higher risk and a substantial subset of high risk-MDS (HR-MDS) were reclassified as lower risk. In LR-MDS a differentiation block is observed in the erythroid lineage. The diagnosis and follow up of cytopenias in particular anemia must be the main objective (1). The soluble transferrin receptor (sTfR) directly reflects the erythropoietic activity in individuals without iron defiency and may appreciate ineffective dysplastic erythropoiesis in LR-MDS.In LR-MDS there is also an inverse relationship between EPO level and the degree of anemia but a wide range of EPO levels is found in patients with similar Hb concentrations. Thus the highest EPO levels are found in patients with erythroid hypoplasia in bone marrow.AimsThe combination of several biomarkers: Hb, ferritin, EPO and sTfR may be useful in LR-MDS for diagnosis and follow up.MethodsA total of 192 patients with LR-MDS were investigated. Median age of the 192 patients was 71 years (21-92) with 56% males, median survival: 54 months, median follow up: 102 months. The stratification according to the WHO criteria and IPSS risk score was realized. Bone marrows were studied and cytogenetic assessment was realized in the same time. Serum concentrations of ferritin, EPO and sTfR has been analyzed by immuno-assays. Hb level was determined on Beckman Coulter apparatus. The follow up of Hb, ferritin, EPO and sTfR was realized every 2 months in patients with supportive care only until the first specific treatment. A multivariate logistic regression analysis to ascertain the correlations between disease progression and studied biological parameters was realized.ResultsThe logistic regression analysis of our results is significant to define a biological evolutive profile of LR-MDS patients with these biomarkers. The combination of these routine parameters may represent a functional erythropoietic follow up in LR-MDS patients (table 1). This biological tool is an easy method to observe the red cell lineage of LR-MDS patients. This combination informs about the progressive ineffective and dysplatic erythropoiesis in LR-MDS patients. The measurement of ferritin which is a correlated parameter in LR-MDS shows the level of iron overload. A normal or high level without inflammation condition excludes an iron deficiency. The EPO level can give a predictive information about the future efficacy of ESA (endogenous EPO < 500 U/l).ConclusionWith our results and a correlative logistic regression analysis, we can propose a biological scoring system to appreciate the evolutive anemia of LR-MDS progression in patients. In LR-MDS the management of patients may be based on personalized medicine according a risk assessment with IPSS-R, cytogenetics, mutations and HLA typing (2). But an additional biological and functional predictive scoring system informs about the important independent role of dysplasias particularly anemia in LR-MDS patients before to choose a suitable therapy: transfusions, iron chelation, ESA, TGF-ï¢ pathway inhibitors, G-CSF, immun suppressive treatment, lenalidomide, azacytidine, allogeneic HSCTTable 1Hb ± EPO ±  sTfRDysplastic erythropoiesis without anemiaHb ±  EPO  sTfRStabilized dysplastic erythropoiesisHb  EPO  sTfRUnstabilized dysplactic erythropoiesisHb  EPO  sTfRIneffective dysplastic erythropoiesisEPO < 500 U/l : ESA may be efficient> 500 U/l : ESA will be inefficientFerritin level : iron overload

Complex karyotype in a polycythemia vera patient with a novel SETD1B/GTF2H3 fusion gene

The patient had been diagnosed with polycythemia vera (PV) in 1999, at the age of 61, according to the criteria of the Polycythemia Vera Study Group (PVSG) on the basis of the increased red cell mass by isotope determination, normal oxygen saturation, low plasma erythropoietin level, presence of endogenous erythroid colonies (EEC), and splenomegaly. Histopathology of bone marrow biopsy was also consistent with polycythemia vera with no evidence of increased reticulin fibrosis. A karyotype analysis was not performed at that time. He had been treated initially with phlebotomies and then with hydroxyurea with the aim to obtain a better control of hematocrit; he was under low-dose aspirin. In 2009, 10 years after the diagnosis, while the patient was still being treated with hydroxyurea and phlebotomies, he noticed worsening of general conditions and fatigue, and the appearance of night sweats; he also reported that his spleen volume had increased rapidly in the past few months. He complained of severe pruritus especially after (but not limited to) a shower. He was referred to our center for further evaluation. At presentation, his blood counts were as follows: hemoglobin 157 g/L, hematocrit 54.7%, leukocytes 13.1 × 10⁹ /L, platelets 238 × 10⁹ /L, LDH 856 U/L (normal upper limit, 250 U/L). Blood film examination showed neutrophilia (8.9 × 10⁹ /L) but immature myeloid cells and nucleated erythroblasts were absent. The spleen was 14 cm below the left costal margin, the liver was at 4 cm below the right costal margin. He was found to harbor the JAK2V617F mutation with an allele burden of 85% and the circulating CD34⁺ cell count was 14 × 10⁶ /L. A bone marrow biopsy showed the presence of hyperplasia of myeloid and erythroid lineages, increased number of scattered megakarocytes without overt morphologic abnormalities; reticulin fibrosis was grade 1 according to the European classification. On these basis, we considered the patient as presenting the features of PV according to the 2008 WHO classification of myeloid neoplasms associated with grade 1 reticulin fibrosis.

Update on the WHO classification of myeloid neoplasms

The 2001 WHO Classification of Myeloid Neoplasms was a major advance in the way myeloid malignancies are diagnosed, categorized, and communicated to treating physicians. A major tenet of the system is its reliance on a combination of morphology, immunophenotype, genetics, and relevant clinical information that together define biologically distinct disease entities. Our understanding of the pathogenesis of myeloid neoplasms has evolved rapidly in recent years, largely due to advances in molecular genetic technology and more complete characterization of genetic aberrations and gene expression patterns in various diseases; similarly, treatments have become more refined and increasingly incorporate therapies that target specific genetic lesions. The 2008 WHO Classification incorporated these advances by refining existing disease definitions and introducing new entities. This classification is currently being updated to reflect yet more recent data. In this Symposium, the background principles of bone marrow interpretation with respect to diagnosis of myeloid neoplasms will be reviewed, including accurate morphologic interpretation, use of flow cytometry and immunohistochemistry, and appropriate use of cytogenetics, FISH, and molecular genetic studies. Each category of myeloid neoplasms in the 2008 WHO Classification will be reviewed, with emphasis on recent advances and anticipated updates to the classification.

Acute myeloid leukemia with mutated nucleophosmin ( NPM1): Any hope for a targeted therapy?

Acute myeloid leukemia (AML) carrying nucleophosmin ( NPM1) mutations displays distinct molecular and clinical–pathological features that led to its inclusion as provisional entity in 2008 WHO classification of myeloid neoplasms. Since NPM1 mutations behave as a founder genetic lesion in AML, they could be an attractive target for therapeutic intervention. Here, we discuss the potential for developing targeted therapies for NPM1-mutated AML with focus on: i) interfering with the abnormal traffic of the NPM1 leukemic mutant, i.e. its cytoplasmic dislocation; ii) disrupting the nucleolar structure/function by interfering with residual wild-type nucleophosmin and other nucleolar components acting as hub proteins; and iii) evaluating the activity of epigenetic drugs (e.g. 5-azacytidine) or agents acting on differentiation and apoptosis. As quantitative assessment of NPM1 mutated transcript copies now provides the means to measure minimal residual disease, we also discuss the potential for intervening in NPM1-mutated AML before overt hematological relapse occurs (so-called pre-emptive therapy).

Two steps forward, one step back: 4th WHO classification of myeloid neoplasms (2008)

Two steps forward, one step back: 4^th WHO classification of myeloid neoplasms (2008)

Acute myeloid leukemia with mutated NPM1: diagnosis, prognosis and therapeutic perspectives

Nucleophosmin (NPM1) gene mutations, which cause aberrant cytoplasmic expression of nucleophosmin (NPMc+), are the most frequent genetic alteration in acute myeloid leukemia (AML), being found in about 30% cases. The present review summarizes recent advances in the biology, diagnosis, prognosis and therapy of NPM1-mutated AML. Diagnostic criteria of NPM1-mutated AML are discussed in the light of its recent inclusion in the 2008 WHO classification of myeloid neoplasms. We also outline the most recent findings on prognosis and monitoring of minimal residual disease in NPM1-mutated AML and their implications for therapeutic decisions. Moreover, new insights are presented into the molecular mechanisms underlying perturbed nucleophosmin traffic in NPM1-mutated AML, which provides the rationale for the development of targeted therapies. AML with mutated NPM1 is a leukemia entity with distinct molecular, pathological, and prognostic features.

Changed concepts and definitions of myeloproliferative neoplasms (MPN), myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) in the updated 2008 WHO classification

The purpose of this overview is to discuss the changes in the 2008 WHO classification of myeloid neoplasms, with exclusion of acute myeloid leukaemia. Specific mutations or rearrangements leading to constitutive activation of growth factor receptors or cytoplasmic tyrosine kinases are now recognised as recurrent genetic events characterising the group of myeloproliferative neoplasms (MPN). A newly introduced subgroup consists of patients with persistent eosinophilia and myeloid or lymphoid proliferations harbouring specific genetic changes involving platelet-derived growth factor receptors alpha and beta (PDGFRA and PDGFRB) or fibroblast growth factor receptor 1 (FGFR1). The clinical relevance of recognising myeloid neoplasms with aberrant tyrosine kinase activity is based in novel treatment options with tyrosine kinase inhibitors. The myelodysplastic syndromes (MDS) without increased blasts are further divided into subtypes of refractory cytopaenias with unilineage dysplasia. A new provisional entity is refractory cytopaenia of childhood. Down syndrome- and therapy-related myeloid neoplasms, including MDS, were moved to the section of acute myeloid leukaemia and related precursor neoplasms.

Cytoplasmic nucleophosmin is not detected in blastic plasmacytoid dendritic cell neoplasm

Acute myeloid leukemia carrying cytoplasmic mutated nucleophosmin (NPMc(+) AML) and blastic plasmacytoid dendritic cell neoplasm have been included as new entities in the 4(th) edition (2008) WHO classification of myeloid neoplasms. These conditions may show clinical and pathological overlapping features (leukemic and skin involvement, and expression of macrophage markers). In this study, we provide evidence that aberrant cytoplasmic dislocation of nucleophosmin - the immunohistochemical surrogate for NPM1 mutations - allows the two entities to be genetically separated. In fact, nucleophosmin is consistently cytoplasmic in NPMc(+) AML (because of the presence of NPM1 mutations), whilst it is nucleus-restricted (predictive of a germline NPM1 gene) in blastic plasmacytoid dendritic cell neoplasm. Our results clearly point cytoplasmic nucleophosmin (a full predictor of NPM1 mutations) as a new marker for distinguishing NPMc(+) AML and blastic plasmacytoid dendritic cell neoplasm, further clarify the cell of origin of NPMc(+) AML, and justify the inclusion of these pathological conditions as separate entities in the new WHO classification.

Presence of JAK2 Mutations in MDS/MPD-u WHO Classified Patients and Not Other Forms of MDS Suggests Their Derivation from Classical Myeloproliferative Syndrome.

The WHO classification of myeloid neoplasms recognizes a category of myeloid disorders that overlaps traditional myelodysplastic syndromes (MDS) and myeloproliferative disorders (MPD) as the entity MDS/MPD disease. This disease category includes CMML, JMML, atypical CML and MDS/MPD unclassifiable (MDS/MPD-u). The provisional entity termed RARS associated with marked thrombocytosis (RARS-t) is currently best classified as MDS/MPD-u until further information is available regarding its pathogenesis. Recently a JAK2 mutation V617F (G→T) was identified as a pathogenetic lesion in typical myeloproliferative disorders (Kralovics et al, NEJM , 2005). Subsequent studies of the JAK2 mutation concentrated on more proliferative forms of MDS or MDS/MPD such as CMML and CNL (Steensma et al, Blood , 2005). These studies demonstrated that homo- and heterozygous JAK2 mutants are present in a rather small proportion of these patients. Based on similar clinical features, we theorized that JAK2 mutants might be also found in patients with MDS/MPD-u. We have collected a cohort of these patients (N=202) and analyzed them for the presence of JAK2 mutation using a molecular allele-specific PCR assay. Positive cases were confirmed by sequencing with a sensitivity of about 20% of mutated cells. A group of patients with PV, MF and ET served as positive controls (N=66). In agreement with previous reports, the detection rate of JAK2 mutants for PV, MF and ET was 92%, 55% and 55%, respectively. Our experimental group included 104 patients with MDS or MDS/MPD (53 RA/RS, 14 RAEB, 22 RAEB-t/sAML, and 15 CMML). Most significantly, the RA/RS group contained 13 patients with WHO-defined MDS/MPD overlap and 3 with RARS-t (among these patients, 3 were JAK2 mutants; all of them were heterozygous - 18.8%). Within 16 patients with CMML1 or 2 we found only 2 heterozygous for JAK2 mutation (12.5%). The remaining cohort of 73 patients in MDS categories revealed only 1 patient to be heterozygous for JAK2 mutation (RARS, 1.4%). As expected MDS/MPD patients with JAK2 mutation showed various degrees of BM fibrosis, splenomegaly and less pronounced cytopenias. Except for one patient, JAK2 mutants had normal cytogenetics. All had normal MCV and ANC. In 4/5 increased megakaryocytes with/or without atypia was seen. One CMML patient with abnormal cytogenetics showed an unusual translocation t(8;9)(q22;p24). JAK2 is located at 9p24 so it is possible that the JAK2 gene was involved in the translocation generating a novel fusion protein in addition to an activating JAK2 mutant. Our results showed that JAK2 mutations are rarely found in typical cases of MDS or CMML. However, further analysis of JAK2 mutational status in patients with MDS/MPD-u is warranted. The reported detection rate may suggest that the pathogenesis of these entities is more akin to myeloproliferative than myelodysplastic syndromes.