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We examined 79 acute myeloid leukemia (AML) patients for DNA methylation of 12 tumor suppressor genes (TSG) and 24 homeobox domain (Hox) genes, and additionally for mutations in DNMT3A gene. We observed lower levels of DNA methylation (P<0.0001) as well as smaller numbers of concurrently hypermethylated genes (P<0.0001) in patients with DNMT3A mutations. Our study of the impact of DNA methylation on prognosis in intermediate and high risk AML patients revealed a relation between higher DNA methylation and better patients' outcome. Lower DNA methylation was linked with higher relapse rates and an inferior overall survival., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A clonal origin of hematopoiesis was studied by investigation of X-chromosome inactivation patterns (XCIP) in isolated granulocyte, CD14(+) and CD3(+) subpopulations obtained from bone marrow and peripheral blood of 36 female patients with primary myelodysplastic syndrome (MDS). Clonality was assessed by PCR amplification of polymorphic short tandem repeats of the human androgen receptor (HUMARA) gene and by investigation of silent polymorphism of iduronate sulphatase (IDS) or p55 genes. On the basis of results in a control group of 20 healthy age related females, a ratio of at least 9:1 between the two alleles was considered a significant marker of monoclonal hematopoiesis. Ten of the 11 patients with advanced forms of MDS (RAEB, RAEB-T, CMML) had clonal granulocytes and CD14(+) cells in peripheral blood. In patients with early disease, only 2 out of 11 patients (18%) with RA or RARS, according to WHO classification, had clonal granulocytes and CD14(+) cells in peripheral blood and bone marrow and 2 other patients with 5q-syndrome exhibited extremely oligoclonal granulocyte subpopulation in bone marrow. In contrast, we found clonal granulocytes in 12 out of 14 patients (86%) with refractory cytopenia with multilineage dysplasia (RCMD) and 8 of them simultanously exhibited clonal CD14(+) cells. Estimated 3 years survival of patients with early disease and clonal cell subpopulations was 61% as compared with 88% in patients without clonal hematopoiesis. Karyotype abnormalities were detected in 11 of the 25 females with early disease. Clonal patterns were present in 7 out of 8 patients with abberations diagnosed by routine cytogenetics, nevertheless, FISH revealed 5q deletion in 3 patients without signs of clonality in XCIP assay. No correlation was found between the presence of clonal subpopulations and the degree of telomere shortening in early MDS. Despite some limitations, the measurement of XCIP remains a sensitive tool for diagnosis of the first transforming mutation in the clonal development of MDS especially when combined with FISH and when an age related group is used to establish an appropriate allele ratio to exclude constitutional or acquired skewing. The occurrence of clonal cell subpopulations in most of the RCMD patients in contrast to RA may reflect a proposed multistep pathogenesis of MDS with dysplastic changes limited to erythropoiesis in early step and with subsequent development of multilineage dysplasia. The results also support the usefulness of separation of RCMD from 'pure' RA; however, a more complex insight combining different molecular techniques performed in a large number of patients is needed for refined classification of MDS on the basis of new molecular prognostic factors and for indication of more effective targeted therapy.

Telomere length was evaluated by terminal repeat fragment method (TRF) in 50 patients with myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) arising from MDS and in 21 patients with untreated primary AML to ascertain, whether telomere erosion was associated with progression of MDS towards overt leukemia. Heterogeneity of TRF among MDS FAB subgroups (P=0.004) originated from its shortening in increased number of patients during progression of the disease. Chromosomal aberrations were present in 32% MDS patients with more eroded telomeres (P=0.022), nevertheless a difference between mean TRF in the subgroups with normal and abnormal karyotype diminished during progression of MDS. A negative correlation between individual TRF and IPSS value (P=0.039) showed that telomere dynamics might serve as a useful prognostic factor for assessment of an individual MDS patient's risk and for decision of an optimal treatment strategy.

A retrospective analysis of the relationship between the initial classification according to either FAB or WHO criteria, the presence of risk factors and the type of therapy including stem cell transplantation (SCT) on the survival was performed in a group of 106 patients with primary myelodysplastic syndrome (MDS) of FAB RA subtype. Allogeneic SCT early in the course of the disease did not significantly affect median survival in RA patients evaluated either according to FAB criteria (63.2 months in 17 SCT patients versus 64.4 months in 89 non-transplanted (non-SCT) patients) or in subgroups classified separately according to WHO (64.0 months in SCT versus 91.0 months in non-SCT RA patients and 66.2 months in SCT versus 43.0 months in non-SCT refractory cytopenia with multilineage dysplasia (RCMD) patients) or International Prognostic Scoring System (IPSS) criteria despite decreased incidence of leukemic transformation (5% in SCT versus 32% in non-SCT patients). Neither univariate or multivariate analysis of different clinical and laboratory parameters revealed a significant effect of SCT on 3 or 5 years survival in RA patients. The most probable explanation was a relatively high rate of transplantation related mortality (41%) on one hand together with a slow disease progression towards leukemia (24% at 5 years in non-SCT) on the other hand. A more refined stratification of patients based on the combined WHO morphology classification and IPSS cytogenetic criteria revealed subgroup of 11 non-SCT patients with RCMD and poor karyotype with median survival significantly different from that in five SCT patients (9.2 months in non-SCT versus 89.3 months in SCT, P=0.05). Thus, combined WHO morphology/IPSS cytogenetics criteria may be helpful for identification of the high risk patients with the RA group who may benefit from early SCT despite the relatively high incidence of SCT-related complications.

Kinetics of BCR-ABL transcript levels were determined in 19 patients with chronic myeloid leukemia (CML) treated with imatinib for chronic (CP) or accelerated phase (AP). Patients could be divided into three groups with: (1) a sharp and sustained decrease in BCR-ABL transcript level reaching 0.1-0.002% (only CP); (2) an early BCR-ABL overexpression up to 2500% (only AP); and (3) a stable trend with BCR-ABL values between 10 and 100% (CP, AP). In group 1, relapses were not developed within the follow-up; in group 2, patients progressed to blast crisis; in group 3, BCR-ABL overexpression appeared after 12 months in some patients and disease relapses were found 2-16 weeks later. It is summarized that BCR-ABL transcript kinetics clearly characterize responses to imatinib treatment and are highly predictive for disease progression.

We monitored DLI treatment of 13 post-SCT relapses using quantitative competitive (QC) RT-PCR for BCR-ABL (sensitivity 10(-5)) and compared responses to DLI alone and DLI in combination with interferon-alpha (IFN). Ten relapses (one blast crisis, five cytogenetic and four molecular) were treated with DLI+IFN, three relapses (one cytogenetic, two molecular) were treated with DLI alone. Except the patient treated in blast crisis, who died, all the patients treated with DLI+IFN achieved complete molecular remission, with the median time interval of 3.9 months (range 0.25-10.5 months). None of the three patients treated with DLI alone have achieved complete molecular remission up to now, i.e. 32, 45, and 50 months after DLI. However, in all of them some decrease of BCR-ABL transcript level was detected. Although the retrospective analyses did not confirm that IFN improved the response to DLI, our results based on sensitive molecular monitoring suggest that DLI effect, at least in some patients, is supported by IFN administration.

A prognostic impact of WHO classification of myelodysplastic syndrome (MDS) was studied in a group of 103 primary MDS patients with refractory anemia (RA) according to French-American-British (FAB) classification. Median survival of 37 patients with RA according to WHO criteria of 85.2 months was significantly different from that in both 37 patients with refractory cytopenia with multilineage dysplasia (RCMD) (47.0 months, P=0.002) and 29 patients with 5q- abnormality diagnosed by routine chromosome banding (36.2 months, P=0.0002). A more detailed karyotype analysis with fluorescent in situ hybridization (FISH) techniques confirmed 5q deletion as a sole cytogenetic abnormality in only 12 out of 29 patients, in 4 patients 5q- was associated with complex abnormalities involving 5q region, 13 patients had 5q deletion combined with further karyotype abberations outside 5q. No difference in median survival and estimated 3 years survival was observed between RA patients, patients with 5q- syndrome according to WHO morphology criteria and patients with 5q- as a single abnormality confirmed by FISH in contrast to patients with either additional 5q abberations or further karyotype changes not involving 5q. The same difference was also observed in time to 25% of patients evolving to acute myeloid leukemia (AML). Our study confirmed usefulness of separation of RCMD from RA. RCMD represents a poor prognostic subgroup of MDS clearly distinct from pure RA mainly due to short survival connected with progressive bone marrow failure and increased risk of leukemic transformation. We also suggest to define 5q- syndrome as primary MDS of FAB type RA with 5q deletion as a sole cytogenetic abnormality confirmed by FISH analysis. This definition enabled us to discriminate 5q- patients with favorable prognosis similar as in RA from those with poor outcome associated with 5q- combined with complex abnormalities involving either 5q or regions outside 5q.

We report three cases of acute myeloid leukemia (AML) with a near-tetraploid karyotype in most metaphases while lacking chromosomal abnormalities typical for AML. All patients, 63, 72 and 81 years old, were female. In two cases, AML was diagnosed 5-7 months after a cytopenic period while the third patient had a secondary AML after therapy for a pleural tumor. Leukemic blasts were classified as AML M0, AML M1 and AML without further specification. Two patients died on the 18th and 52nd day after the start of cytotoxic chemotherapy, the third patient refused chemotherapy and died 22 days after the diagnosis. The three patients may represent a distinct AML category with the following features: (1) the near-tetraploid karyotype in most bone marrow metaphases examined at diagnosis of AML; (2) the presence of very large myeloid blasts in the bone marrow and dysplastic changes in erythroid and/or megakaryocytic lineages pointing to the origin of AML in pluripotent myeloid progenitor cells; (3) the expression of the CD34 antigen; (4) the low growth of granulocyte-macrophage colony forming cells in culture; and (5) the presence of a preleukemic phase, a higher age and a poor prognosis.

Aplastic anemia, myelodysplastic syndromes (MDS) and chronic myeloproliferative diseases (MPD) are stem cell disorders. There is no clear-cut demarcation of them. Hypoplastic MDS displays features of aplastic anemia and MDS, on the other side mixed myelodysplastic and myeloproliferative syndromes (MDS-MPS) develop. In our collection of 566 MDS patients, features of myelodysplasia as well as myeloproliferation, MDS-MPS, were present in 25 patients (4.4%). Twelve patients had at the time of diagnosis megakaryocytic proliferation and thrombocythemia beside signs of MDS, and seven had myelodysplasia with granulocytic proliferation and leukocytosis. In another six patients, MDS was the first diagnosis and the proliferative phase developed later during the course of the disease. These patients can be characterized as MDS-MPS in evolution. All subjects had a variable degree of anemia. While the level of thrombocythemia has been relatively stable, the number of leukocytes has been progressive, but rarely extended beyond 100 x 10(9)/l. Ring-sideroblasts and myelofibrosis were frequent findings. Two more homogeneous MDS-MPS groups emerged in our analysis: sideroblastic anemia with thrombocythemia and a group fulfilling the criteria of Philadelphia chromosome negative and bcr-abl negative "atypical chronic myeloid leukemia (aCML)'. One patient with thrombocythemia and three with leukocytosis (23%) transformed to acute myeloid leukemia (AML). Men prevailed (12/13) in patients with leukocytosis and MDS-MPS in evolution. Of the 46% MDS-MPS patients with chromosomal aberrations, del(20)(q) is of interest.

240 patients with MDS studied cytogenetically at diagnosis between 1981 and 1990 were followed until death or until April 1992 to evaluate the prognostic significance of FAB classification, age and karyotype. 61 patients (25.4%) subsequently transformed into AML and 176 (73.3%) died during the follow-up period. Patients with blastic MDS types had a shorter survival and a higher probability of leukemic transformation. The younger age increased the probability of leukemic transformation, but was associated with a longer survival. The absence of analyzable mitoses was associated with a shorter survival. The complex chromosomal abnormalities at the initial evaluation identified a subgroup of patients with a high risk of a short survival and/or subsequent leukemia transformation. In refractory anemia the presence of complex chromosomal abnormalities was linked with a relative risk of 3.58 of leukemic transformation and shorter survival as compared with other cytogenetically defined groups.

Leukemic blasts of two patients with acute leukemia exhibited similar characteristics. They were heterogeneous in size with a diameter of 14-30 microns in smears and unclassifiable by morphological, cytochemical, immunophenotypic and ultrastructural examinations. Cytogenetic examinations of both revealed a near-tetraploid karyotype. Blasts from both patients differentiated into macrophages in cultures with 10 ng/ml 12-O-tetradecanoylphorbol-13-acetate (TPA) which is a feature specific for myeloid blasts and the cases were thus classified as poorly differentiated acute myeloid leukemias (AML M0). Near-tetraploid poorly differentiated acute myeloid leukemias M0 seem to be a special category of AML in the morphologic, immunologic and cytogenetic (MIC) classification. The presence of very large blasts in the heterogeneous blast population in acute unclassified leukemias could be a morphological sign of near-tetraploid leukemias AML M0.