Bone Marrow WT1 Levels in Allogeneic Hematopoietic Stem Cell Transplantation for Acute Myelogenous Leukemia and Myelodysplasia: Clinically Relevant Time Points and 100 Copies Threshold Value.

The outcome of allogeneic hematopoietic stem cell transplantation (HCT) in patients with myeloid malignancies is better in those without minimal residual disease (MRD) than in those with MRD+, as assessed by multiparametric flow cytometry (MPFC). WT1 quantitation also has been used to assess the probability of relapse in acute myelogenous leukemia (AML) treated with chemotherapy. We analyzed the clinical value of normalized bone marrow WT1 levels as a measure of the expanded myeloid progenitor compartment in a consecutive series of 193 adult patients with myeloid malignancies who underwent HCT.

Feasibility of the AML profiler (Skyline™ Array) for patient risk stratification in a multicentre trial: a preliminary comparison with the conventional approach.

Deoxyribonucleic acid microarrays allow researchers to measure mRNA levels of thousands of genes in a single experiment and could be useful for diagnostic purposes in patients with acute myeloid leukaemia (AML). We assessed the feasibility of the AML profiler (Skyline™ Array) in genetic stratification of patients with de novo AML and compared the results with those obtained using the standard cytogenetic and molecular approach. Diagnostic bone marrow from 31 consecutive de novo AML cases was used to test MLL-PTD, FLT3-ITD and TKD, NPM1 and CEBPAdm mutations.

Bone marrow WT1 levels at diagnosis, post-induction and post-intensification in adult de novo AML.

We retrospectively assessed whether normalized bone marrow WT1 levels could be used for risk stratification in a consecutive series of 584 acute myeloid leukemia (AML) patients. A cutoff value of 5065 copies at diagnosis identified two prognostic groups (overall survival (OS): 44 ± 3 vs 36 ± 3%, P=0.023; leukemia-free survival (LFS): 47 ± 3 vs 36 ± 4%, P=0.

Adverse impact of IDH1 and IDH2 mutations in primary AML: experience of the Spanish CETLAM group.

The study of genetic lesions in AML cells is helpful to define the prognosis of patients with this disease. This study analyzed the frequency and clinical impact of recently described gene alterations, isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2) mutations, in a series of homogeneously treated patients with primary (de novo) AML. Two-hundred and seventy-five patients enrolled in the CETLAM 2003 protocol were analyzed.

Immunophenotype of acute myeloid leukemia with NPM mutations: prognostic impact of the leukemic compartment size.

NPM mutations are the most common genetic abnormalities found in non-promyelocytic AML. NPM-positive patients usually show a normal karyotype, a peculiar morphologic appearance with frequent monocytic traits and good prognosis in the absence of an associated FLT3 mutation. This report describes the immunophenotypic and genetic characteristics of a consecutive series of NPM-mutated de novo AML patients enroled in the CETLAM trial.

WT1 monitoring in core binding factor AML: comparison with specific chimeric products.

Minimal residual disease may help to establish clinical decisions in patients with AML. WT1 offers the possibility to analyze those cases without currently known underlying genetic abnormalities. To compare the value of chimeric specific quantitative PCR with WT1 PCR in CBF acute leukemia, 445 samples from 96 AML (49 AML1-ETO+ and 47 CBFB-MYH11+) cases were included in the study.

Uniparental disomy may be associated with microsatellite instability in acute myeloid leukemia (AML) with a normal karyotype.

The discovery of underlying genetic lesions helps to better understand the mechanisms of leukemogenesis and identify prognostic subgroups. Recent insights have allowed normal karyotype acute myeloid leukemia (AML) to be split into many molecular entities according to the genetic status of FLT3, NPM, CEBPA and MLL. Genome-wide single nucleotide polymorphism analysis was performed on 22 well-characterised AML patients with a normal karyotype.

The V617F mutation of JAK2 is very uncommon in patients with thrombosis.

Given that many cases of thrombosis do not have a clear cause, a myeloproliferative disease could be involved. We investigated the V617F mutation of the JAK2 gene in 295 patients with thrombosis. Only one case was positive.

[Evaluation of V617F mutation of JAK2 in negative chromosome Philadelphia chronic myeloproliferative disorders].

Background And Objective: Polycythemia vera (PV) and essential thrombocytemia (ET) are chronic myeloproliferative diseases (MPD) characterized by overactive hemopoiesis. A single point mutation of JAK2 (Val617Phe) has been detected in PV, ET and myelofibrosis (MF). The aim of this work was to investigate the JAK2 mutation in patients with MPD and to compare the results to those of the endogenous formation of BFU-E erythroid colonies (EEC).

Occurrence of the JAK2 V617F mutation in the WHO provisional entity: myelodysplastic/myeloproliferative disease, unclassifiable-refractory anemia with ringed sideroblasts associated with marked thrombocytosis.

The JAK2/V617F mutation has been noted in essential thrombocytemia. We investigated 19 cases with refractory anemia with ringed sideroblasts (RARS), including three RARS with thrombocytosis (RARS-T). Only the RARS-T patients showed this mutation.

Microsatellite instability is not an uncommon finding in adult de novo acute myeloid leukemia.

To investigate the biologic relevance of microsatellite instability (MSI) in de novo acute myeloid leukemia (AML), 102 consecutive adult patients were analyzed by using a panel of seven microsatellites (BAT25, BAT26, D13S1267, D13S174, D2S123, D5S346 and Mdf15). Frame-shift mutations in the repetitive sequences in the coding region of MSH3, MSH6, BAX, TGFBRII and IGFRII were also investigated by using a fluorescent PCR-based assay. Methylation-specific PCR was used to determine the methylation status of hMLH1 in MSI+ cases.

MEIS 1 expression is downregulated through promoter hypermethylation in AML1-ETO acute myeloid leukemias.

Retroviral insertional mutagenesis in BXH2 mice commonly induces myeloid leukemias. One of the most frequently involved genes in experimental studies is Meis 1. In contrast to other genes in murine models, Meis 1 has not been affected by recurrent chromosomal translocations or point mutations in human leukemias.

FLT3 mutations are associated with other molecular lesions in AML.

The basic molecular defects underlying acute myeloid leukemias (AML) seem to be caused by inactivating mutations in transcription factors which control normal myeloid differentiation (Class II mutations) and genetic lesions in tyrosine kinases resulting in constitutive activation (Class I mutations). We sought to determine the frequency of associated mutations (Class I + Class II) in a consecutive series of adult de novo AML (353 patients) in order to stress the validity of this model. Mutations and rearrangements at the FLT3, AML1/ETO, CBFbeta/MYH11, AML1, CEBPalpha and MLL genes were investigated using standard molecular methods.

Id4 is deregulated by a t(6;14)(p22;q32) chromosomal translocation in a B-cell lineage acute lymphoblastic leukemia.

Background And Objectives: Chromosome translocations resulting in gene overexpression are commonly associated with lymphoid neoplasia. Enhancer elements of the immunoglobulin or T-cell receptor (TCR) loci are abnormally located in the vicinity of the entire coding sequences of genes which exert an influence on the normal maturation and differentiation program of lymphoid cells.

Design And Methods: A patient who presented with a B-cell lineage acute lymphoblastic leukemia had a t(6;14)(p22;q32).

Bcl-6 p53 mutations in lymphomas carrying the bcl-2/Jh rearrangement.

Background And Objectives: The t(14;18)(q32;q21) chromosomal translocation is the hallmark of follicular lymphomas (FL). The translocation induces the overexpression of the Bcl-2 protein and prolongs the survival of clonogenic cells. Tumor cells may acquire additional molecular alterations that may be associated with histologic progression or with chemo-resistance.

Clonal heterogeneity assessed by flow cytometry in B-cell lymphomas arising from germinal centers.

Patients with mature follicular B-cell lymphomas develop aggressive non-Hodgkin lymphomas (NHLs) during disease progression. It is controversial whether most diffuse large B-cell lymphomas (DLBCLs) and Burkitt lymphomas (BLs) emerge as de novo lymphomas or from an original follicular lymphoma. To distinguish clonally related populations in aggressive NHL, we studied the immunophenotypic features of 18 consecutive samples from 16 patients.

Flow cytometry using the monoclonal antibody CD10-Pe/Cy5 is a useful tool to identify follicular lymphoma cells.

Follicular lymphoma (FL) is a specific entity defined by characteristic histology, phenotype and molecular rearrangements. Classically, reactivity for CD19, CD10, and strong positivity for the surface light chain immunoglobulin (SIg) are considered to be phenotypic signs typically expressed in FL. In practice, this pattern is difficult to identify since most neoplastic cells analysed by flow cytometry (FC) show weak intensity for CD19-Pe/Cy5 and for SIg and negativity for CD10-FITC.

[Mutational analysis of p53 in T-cell lymphoblastic leukemia].

Background: p53 mutations were analysed in a consecutive series of patients with T-ALL from one hospital over a period of 9 years.

Patients And Method: Thirty two samples from 27 patients with T-ALL were included in the study. Exons 5-9 were analysed using SSCP.

Enhanced myeloid specificity of CD117 compared with CD13 and CD33.

The c-kit proto-oncogene encodes a 145 kd tyrosine kinase transmembrane receptor, which plays a key role in haemopoiesis. The c-kit has been classified as CD117 and is especially useful in the differential diagnosis of acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL). We analysed 104 consecutive cases (55 AML, 23 B-cell lineage ALL, three T-cell ALL, 11 blast crisis of chronic myeloproliferative disorders and 12 cases of myelodysplastic syndromes with more than 10% of blasts) referred to our Hospital for immunophenotypic diagnosis and compared the expression pattern of CD13, CD33 and CD117 using the same fluorochrome (phycoerythrin-PE).