Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormalities of chromosome band 13q14 occur in hematologic malignancies of all lineages and at all stages of differentiation. Unlike other chromosomal translocations, which are usually specific for a given lineage, the chromosomal translocation t(12;13)(p12;q14) has been observed in both B-cell and T-cell precursor acute lymphoblastic leukemia (BCP-, TCP-ALL), in differentiated and undifferentiated acute myeloblastic leukemia (AML), and in chronic myeloid leukemia (CML) at progression to blast crisis. The nature of these translocations and their pathologic consequences remain unknown. To begin to define the gene(s) involved on chromosome 13, we have performed fluorescence in situ hybridization (FISH) using a panel of YACs from the region, on a series of 10 cases of acute leukemia with t(12;13)(p12;q14) and 1 case each with "variant" translocations including t(12;13)(q21;q14), t(10;13)(q24;q14) and t(9;13)(p21;q14). In 8/13 cases/cell lines, the 13q14 break fell within a single 1.4 Mb CEPH MegaYAC. This YAC fell immediately telomeric of the forkhead (FKHR) gene, which is disrupted in the t(2;13)(q35;q14) seen in pediatric alveolar rhabdomyosarcoma. Seven of the 8 cases with breaks in this YAC were AML. In 4/13 cases, the 13q14 break fell within a 1.7-Mb YAC located about 3 Mb telomeric of the retinoblastoma (RB1) gene: all 4 cases were ALL. One case of myelodysplastic syndrome exhibited a break within 13q12, adjacent to the BRCA2 gene. These data indicate the presence of myeloid- and lymphoid-specific breakpoint cluster regions within chromosome band 13q14 in acute leukemia.
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PMID:Myeloid- and lymphoid-specific breakpoint cluster regions in chromosome band 13q14 in acute leukemia. 1037 68

P-glycoprotein (P-gp) is often expressed (40-50%) on leukemic cells at diagnosis in acute myelogenous leukemia (AML), and is even more frequently present after treatment failure. Several large cohorts of newly diagnosed AML patients treated with a classical anthracycline + standard doses of cytosine arabinoside were tested for the prognosis value of MDR1 phenotype, and demonstrated an high correlation between a significant increase of MDR1 gene expression and treatment failure (or, better, drug resistance). This P-gp(+) drug resistance could be due either to a particular phenotype of bad prognosis AML, as it is suggested by the association of myelodysplasia, complex karyotype and advanced age with MDR1 phenotype, or due primarily to the active efflux of anthracyclines and VP16 in P-gp(+) leukemic cells. Several observations tend to confirm the functional role of the P-gp in clinical drug resistance; (i) using multivariate analysis, MDR1 phenotype appears to be an independent variable, as potent (or higher) as karyotype and age for predicting in vivo drug resistance; (ii) the prognostic value is limited to the CD34(+)/P-gp(+) phenotype, wich is linked to a functional P-gp; (iii) the in vitro sensitivity to anthracyclines and VP16 is highly correlated with P-gp expression. All these data argue for an early use of P-gp modifier agents in the treatment of AML. The role of the MDR1 gene in ALL resistance is controversial and marginal compared to the sensitivity of ALL blasts to glucocorticoids, and the frequency of MDR1 phenotype is low at diagnosis, and is increasing only after repetitive chemotherapies.
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PMID:MDR1/P-GP expression as a prognostic factor in acute leukemias. 1050 Jul 74

The long arm of chromosome 20 displays recurrent loss of heterozygosity (LOH) for microsatellite markers in blast cells from children with acute lymphoblastic leukemia. To further characterize the region of deletion and to precisely establish its frequency, we searched for LOH in 103 children with ALL using polymorphic markers in the previously described region of interest, namely between D20S101 and D20S887. LOH was detected in nine patients (ie with a frequency of 8.7%). Interestingly, in one patient, a small deletion was found, flanked proximally by D20S850 and distally by M201, a dinucleotide repeat identified from chromosome 20 sequences. The distance between these two markers is approximately 1000 kb. The occurrence of non-random deletions of the long arm of chromosome 20 has previously been observed in myeloid malignancies (myeloproliferative disorders and myelodysplastic syndromes) in 5-10% of patients. The small deletion in our patient is located within the common region of deletion of myeloproliferative disorders suggesting that a tumor suppressor gene may be the common target of the deletions in various types of hematological malignancies.
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PMID:Mapping of chromosome 20 for loss of heterozygosity in childhood ALL reveals a 1,000-kb deletion in one patient. 1060 17

The success of allogeneic stem cell transplantation (allo-SCT) in children is mainly affected by relapse or graft rejection. We have recently shown in a study of 55 patients with acute leukemias (ALL 21, AML 20 and MDS 14), that patients who demonstrate increase amounts of autologous marrow repopulation (increasing mixed chimerism) have a significantly enhanced risk of relapse (P < 0. 0001). Based on these findings, we asked whether post-transplant relapse can be prevented by withdrawal of immunosuppression and/or by donor lymphocyte infusion (DLI). We describe the results of a pilot study where adoptive immunotherapy was used to treat 12 patients (five ALL, three AML, four MDS) who showed increasing mixed chimerism (MC) post-transplant. A response to immunotherapy, defined as the re-establishment of complete chimerism (CC) and continuous complete remission (CCR), was achieved in four patients (two ALL, two AML) following withdrawal of CsA and in a further six patients (three ALL, three MDS) after additional DLI. One ALL patient, who initially responded to DLI, developed severe GVHD that required further immunosuppression. GVHD was controlled but this patient subsequently relapsed. Another patient with ALL became a CC but developed an isolated relapse in the bone marrow 260 days later. One patient with MDS developed severe GVHD after DLI and died. Two children (one AML and one MDS) did not show any response to interventional treatment and died due to relapse. Of the 12 patients treated, seven remain in CCR at a median follow-up of 747 days (range 351-1109 days). In summary, these results provide evidence that increasing MC can be used to guide adoptive immunotherapy strategies and that these treatment modalities can be used to prevent relapse in children with acute leukemias or MDS after allo-SCT.
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PMID:Prevention of relapse in pediatric patients with acute leukemias and MDS after allogeneic SCT by early immunotherapy initiated on the basis of increasing mixed chimerism: a single center experience of 12 children. 1060 32

We describe an 84-year-old woman who presented severe pancytopenia and 36.6% of blasts accompanied with erythrophagocytosis in the bone marrow. According to cytochemical and immunological findings, a diagnosis of minimally differentiated acute myeloid leukemia (AML-M0) was established. Cytogenetic analysis revealed del(20)(q11) which were previously reported for one case each of ALL and MDS associated with cytophagocytosis by blasts, leading us to speculate a disease entity. Interestingly, a high expression of mRNA of TNF-alpha was detected by RT-PCR on the bone marrow mononuclear cells.
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PMID:Minimally differentiated acute myeloid leukemia (AML-M0) with extensive erythrophagocytosis and del(20)(q11) chromosome abnormality. 1063 52

Between October 1995 and October 1998, 24 children aged 9 months to 17 years (median 11 years) underwent cytokine-mobilized allogeneic peripheral blood stem cell (PBSC) transplantation for treatment of hematological disorders. All of the transplants were the first allogeneic transplant for the recipient. Twenty patients were transplanted for hematological malignancies (ALL = 8, AML = 6, CML = 4, MDS = 2) and four patients were transplanted for non-malignant disease (thalassemia major = 2, Wiskott-Aldrich syndrome = 1, Kostmann's syndrome = 1). Nineteen donors were HLA-identical siblings, four were HLA-matched or single antigen mismatched parents, and one was a syngeneic transplant. Donors aged 8 to 38 years (median 15 years, 14 donors <18 years) received G-CSF 10 microg/kg/day subcutaneously beginning 4 days before PBSC collection and were submitted to one to three leukapheresis collections. The median CD34+ cell yield was 7.8 x 106 cells/kg recipient body weight. All patients achieved an ANC >0.5 x 109/l after a median of 13 days (range 10-21). Twenty-three patients eventually achieved platelet transfusion independence. One patient died on day 63 without ever achieving platelet transfusion independence. Four patients received platelet transfusions to maintain a platelet count well above 20 x 109/l due to bleeding complications. Of the 19 evaluable patients, the median time to a non-transfused platelet count of 20 x 109/l was 12 days (range 0-44). Ten of 23 at-risk patients developed acute GVHD grades II to IV, with grades III to IV in four patients. Twelve of 19 patients followed for at least 100 days have developed chronic GVHD (extensive = 2, limited = 10) with an actuarial risk of chronic GVHD of 75% at 1 year. The Kaplan-Meier estimate of event-free survival is 65% at 2 years. Four patients died (GVHD = 3, VOD = 1), three patients relapsed, and one patient with thalassemia major had a late graft failure with autologous recovery. Based upon our experience, allogeneic PBSCT is safe for both pediatric donors and recipients and engraftment of neutrophils and platelets is rapid. Bone Marrow Transplantation (2000) 25, 13-18.
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PMID:Cytokine-mobilized allogeneic peripheral blood stem cell transplants in children result in rapid engraftment and a high incidence of chronic GVHD. 1065 8

Wilms' tumor gene WT1 mRNA is a new marker of leukemic blast cells for AML, ALL, and CML. Minimal residual disease(MRD) of leukemia can be detected at frequencies as low as 1 in 10(3) to 10(4) normal bone marrow cells and 1 in 10(5) normal peripheral blood mononuclear cells by means of the quantitation of WT1 mRNA(WT1 assay) using reverse transcriptase-polymerase chain reaction. Thus, the WT1 assay makes it possible to rapidly assess the effectiveness of treatment and to evaluate the degree of eradication of leukemic cell in individual leukemia patients. Furthermore, WT1 assay can continuously assess the disease progression of myelodysplastic syndromes(MDS) and predict the evolution of MDS to overt AML within 6 months.
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PMID:[Genetic diagnosis of leukemia: diagnosis of relapse and complete remission, and prediction of leukemia onset]. 1080 19

Peripheral blood stem cell transplants (PBSCT) from unrelated donors (n = 37) were compared with bone marrow transplants (BM, bone marrow group, n = 37) in a matched pair analysis. Ten patients (2, class 1) in the alloPBSCT group and seven patients (2, class 1) in the BM group had one HLA locus mismatch donor, respectively. The following factors were matched: HLA-compatibility, diagnosis, disease stage, age and gender. The median age in the PBSC group was 37 years (19-56, excluding one 6-year-old child) and in the BM group 37 years (18-53). The BM group consisted of 12 females and 25 males, 17 females and 20 males were in the PBSC group. Twelve patients in the BM and 11 patients in the PBSC group were diagnosed with AMI,; 7/7, ALL; 15/15, CML; 2/3, MDS; 1/1, NHL. Thirty-four (14/20) of the 74 patients (45%) were considered as high risk patients. The conditioning regimen was BU/CY for standard risk patients with myeloid diseases (31 patients) and TBI/CY for ALL and NHL patients (36 patients); six patients received intensified conditioning with VP16 (2 patients), thiotepa (2 patients) or melphalan (1 patient). The GVHD prophylaxis regimen was used according to the Seattle protocol. DFS was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days, in PBSC and BM transplants, respectively. The median time to leukocyte engraftment in PBSC patients was 14 days (range 6-26 days) and in the BM group 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly between the groups. The incidence of grade II-IV acute GVHD was 40% (four patients died, 13%) in the PBSC group and 20)% (three patients died, 8%) in the BM group, respectively (P < 0.05, log-rank). No signs of aGVHD were found in 19% of the patients in the PBSC and 27% in the BM group. Our results indicate that allogeneic PBSCT does lead to a significantly faster leukocyte engraftment. The significant increase with regard to the incidence and shorter time of onset of severe aGVHD in PBSC patients, compared to marrow transplant patients, need to be confirmed in a randomised trial.
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PMID:A comparative study of peripheral blood stem cell vs bone marrow transplantation from unrelated donors (MUD): a single center study. 1093 83

MLF1 is a novel protein identified as the NPM-MLF1 chimeric protein produced by a t(3;5)(q25.1;q34) chromosomal translocation, which is associated with myelodysplastic syndrome (MDS), often prior to acute myeloid leukemia (AML), except for M3. The clinical features of t(3;5)-positive myeloid disorders suggest that this chimeric protein is involved in dysregulation of progenitor cells with the capability to differentiate into multiple lineages. So far, involvement of wild-type MLF1 in hematopoiesis or in leukemogenesis has not been fully investigated. In the present study, 65 patients with AML and 44 patients with MDS were tested for the expression of MLF1 using the quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. A significantly higher level of MLF1 expression (ratio of MLF1/beta-actin mRNA >0.4) was readily detected in seven of 65 patients with de novo AML, three of 12 with post-MDS AML and seven of 44 with MDS, but not in any patients with ALL (n = 18). According to the FAB classification, high levels of MLF1 were found in patients with relatively immature subtypes of AML (M1, M2, M6 and M7) and high risk MDS (RAEB and RAEB-T). These findings indicate that the pattern of MLF1 expression is identical to the clinical morphology appearing in the t(3;5)-positive myeloid disorders and is correlated to the MDS-associated AML and transformation phase of MDS in t(3;5)-negative myeloid disorders. A CD34+ population of normal bone marrow cells preferentially expressed MLF1 with obviously decreasing levels of expression during maturation. Therefore, MLF1 normally functions in multi-potent progenitor cells and its dysregulation may take part in leukemogenesis from MDS.
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PMID:Elevated MLF1 expression correlates with malignant progression from myelodysplastic syndrome. 1102 51

We evaluated 443 outpatients and inpatients in Keio University Hospital between 1994 and 1999. Morphologic features from peripheral blood and bone marrow aspiration were evaluated in our hematology laboratory, using Wright-Giemsa, peroxidase staining films and other cytochemistry. Immunophenotype was determined by cell surface antigen analysis by laser flow cytometry, FACscan, using various monoclonal antibodies. Information on cytogenetic and molecular genetic characteristics can be also integrated for diagnosis. One hundred fifty patients were diagnosed with acute leukemia, in which 59 cases were ALL and 91 cases were AML. Seventy-four cases were MDS, 76 cases were myeloproliferative disorders, 21 cases were CLL related disorders, 104 patients were malignant lymphoma, and 18 cases were multiple myeloma. The ratio of male to female was 1.7. The probability of diagnostic rate by Immunophenotyping was estimated by Discriminant analysis in 189 patients, using multivariate analysis of immunophenotype compared to morphology. The average probability by immunophenotypic analysis for diagnostic rate was 91.7%, in which the probability for NHL was very high of 97.1%. Thus, morphologic and immunophenotypic analysis is most essential and basic approach in laboratory hematology, from the perspective of rapid and precise diagnostic methods. Recent advance appreciates the rapid contribution for diagnosis by immunophenotypic analysis. Furthermore, Tele-hematology would contribute the standardization for morphologic method in the near future.
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PMID:[Morphology and immunophenotyping in hematological malignancies]. 1106 91


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