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)

Chronic myeloproliferative disorders (CMPD) are neoplastic disorders of the hematopoietic stem cell. Four different entities are defined: chronic myeloid leukemia (CML), polycythemia vers, essential thrombocythaemia, and idiopathic myelofibrosis. In addition, overlapping entities within the CMPDs and between CMPDs and myelodysplastic syndrome have been described. Diagnostic measures are performed to classify the subtype exactly and to assess risk factors and prognosis. Cytogenetic and molecular analyses are mandatory for the characterization of the malignant clone. Hydroxyurea and interferon-alpha have proven effective in all CMPE. In CML, specific inhibition of the elevated ABL tyrosine kinase activity with imatinib is associated with high response rates. Allogeneic stem cell transplantation is the only curative treatment option for all entities. In CML, the decision-making analysis should be based on established scores. In BCR-ABL negative CMPDs an allogeneic stem cell transplantation should only be performed in patients with unfavorable prognosis.
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PMID:[Chronic myeloproliferative diseases. Diagnosis and therapy]. 1467 16

Myeloproliferative disorders (MPDs) are chronic conditions that require long-term treatment. MPDs have been considered neoplastic disorders that have a propensity to transform to acute leukemia or myelodysplastic syndrome. One of the MPDs, chronic myeloid leukemia (CML), has the distinct cytogenetic abnormality of the Philadelphia chromosome. In CML, transformation to acute leukemia is a common occurrence, with the timeline measured in years rather than decades. With the other three disorders from this group, polycythemia vera (PV), essential thrombocythemia (ET), and idiopathic myelofibrosis (IMF), transformation to acute leukemia is less frequently seen and, although variable, can take a longer period of time. The choice of therapy used for MPDs may contribute to leukemic transformation; chlorambucil, busulfan, and radiophosphorus are all examples of therapy that have been shown to be leukemogenic. Several studies have suggested the potential leukemogenicity of hydroxyurea (HU), but this remains controversial because no randomized studies have been conducted. The two newest agents used for MPDs, interferon-alpha and anagrelide, have both been studied for efficacy, but their influence on the potential for leukemic transformation has not been well studied to date.
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PMID:Treatment paradigms in the management of myeloproliferative disorders. 1519 May 19

Basic fibroblast growth factor (bFGF) is an important growth factor involved in clonal hematopoietic expansion, neoangiogenesis, and bone marrow fibrosis, all of which are important pathobiologic features of clonal chronic myeloproliferative disorders (CMPD) and myelodysplastic syndromes (MDS). The aim of this study was to assess circulating bFGF concentrations in patients with CMPD and MDS with respect to the presence of bone marrow fibrosis in histopathologic examination. The study group comprised 18 patients with CMPD (six female, 12 male; median age 50 years), seven patients with MDS (one female, six male; median age 66 years) and 10 healthy adults as controls (four female, six male; median age 29 years). CMPD group included six chronic myelogenous leukemia (CML), seven essential thrombocythemia (ET), three polycythemia vera (PV), two agnogenic myeloid metaplasia (AMM). All seven MDS patients were the FAB subtype of refractory anemia (RA). Bone marrow biopsy sections stained with hematoxylin and eosin (H & E) and for reticulin were examined for the presence of fibrosis. The median plasma bFGF level was 18.2 pg/ml (interquartile range, IQR: 15.2-26.7) in patients with CMPD, 18.0 pg/ml (IQR: 15.8-26.4) in patients with MDS, 13.6 pg/ml (IQR: 9.9-20.0) in the control group. The bFGF levels were significantly higher in patients with CMPD in comparison with the healthy control group (P = 0.031). Circulating bFGF tended to be significantly lower in relation to the development of marrow fibrosis (P = 0.028). The complicated interactions of bFGF and fibrosis in the context of CMPD may be either 'cause' or 'effect'. The bFGF might represent an important link between angiogenesis, fibrosis, and clonal neoplastic hematopoiesis during the development of CMPD.
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PMID:Plasma basic fibroblast growth factor and bone marrow fibrosis in clonal myeloproliferative disorders. 1527 63

The PRV-1 gene has been proposed as a marker of polycythaemia vera (PV). PRV-1 and NB1 are alleles of the polymorphic gene CD177, which belongs to the Ly-6/uPAR superfamily, and their coding regions differ at only four nucleotides. We studied neutrophil CD177 mRNA levels in normal subjects and in 235 patients with Ph-negative chronic myeloproliferative disorders (CMD), including PV, essential thrombocythaemia and myelofibrosis with myeloid metaplasia. Additional disease states were investigated for comparison. Highly variable neutrophil CD177 mRNA levels were observed in normal individuals. Neutrophils isolated from the bone marrow, or from peripheral blood following granulocyte colony-stimulating factor administration showed markedly higher CD177 expression than circulating granulocytes on steady state. Increased neutrophil CD177 mRNA levels were detected in all CMD. Elevated values were also found in reactive conditions and in disorders such as chronic myeloid leukaemia and myelodysplastic syndromes. In the differential diagnosis between PV and secondary erythrocytosis, the assay sensitivity was 68% while its specificity was 60%. These findings indicate that an elevated neutrophil CD177 mRNA level is not a specific marker for the diagnosis of PV nor for that of CMD. From a clinical viewpoint, neutrophil CD177 mRNA overexpression is rather a marker of abnormal neutrophil production and/or release in patients with CMD.
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PMID:Clinical significance of neutrophil CD177 mRNA expression in Ph-negative chronic myeloproliferative disorders. 1532 15

Thalidomide has re-emerged as a novel antineoplastic agent with immunomodulatory and antiangiogenic activities. In the early sixties, it was withdrawn from the market after its infamous association with congenital abnormalities that left about 10,000 children affected world-wide. With strict regulations and precautions, thalidomide is now approved by the FDA for the treatment of erythema nodosum leprosum. Its role in cancer therapy is promising, with clinical trials in the past 5 years showing significant activity in multiple myeloma. Several trials are ongoing in other malignancies, such as myelodysplastic syndrome, agnogenic myeloid metaplasia, renal cell carcinoma, and prostate cancer. The major toxicities of thalidomide are birth defects, sensorimotor peripheral neuropathy, somnolence, rash, fatigue, and constipation. Less common side effects include deep venous thrombosis, Stevens-Johnson syndrome, elevated liver enzymes, malaise, and peripheral edema. The incidence and severity of adverse events are related to dose and duration of therapy. Doses of the drug of 200 mg/day or less are usually well tolerated. In this review, we will discuss the incidence and management of the side effects of thalidomide and the precautions and interventions needed to minimize the toxicities of this drug.
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PMID:Management of thalidomide toxicity. 1533 75

Among 56,709 cytogenetic studies performed during a 15-year period at the Mayo Clinic, 25 cases of t(5;12) were identified. Among 11 patients with available clinical information, 4 had myelodysplastic syndrome, 2 had acute myelocytic leukemia, 2 had myelofibrosis with myeloid metaplasia (MMM), 2 had atypical chronic myelocytic disorder (ACMD), and 1 had chronic myelomonocytic leukemia (CMMoL). The 5q arm was involved in all patients and the 12p arm in only two patients [ACMD,t(5;12)(q33;p13) and MMM,t(5;12)(q11.2;p11.2)], both of whom had eosinophilia and monocytosis. These two features were present in only two other patients [CMMoL,t(5;12)(q35;q24.1) and ACMD,t(5;12)(q31;q24.1)]. The t(5;12) is a rare, myelocytic-exclusive cytogenetic abnormality with a breakpoint-specific association with eosinophilia or monocytosis.
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PMID:Prevalence, breakpoint distribution, and clinical correlates of t(5;12). 1535 Mar 8

The Cord Blood Transplantation study group conducted a prospective study of unrelated cord blood transplantation (CBT) to better define the role of this stem cell source for subjects requiring unrelated allogeneic transplantation. We report on 1 stratum of the study designated for adult subjects. The primary end point of the study was survival at 180 days. Secondary end points included engraftment, graft-versus-host disease, relapse, and long-term survival. Eligibility criteria for malignant and nonmalignant diseases were specified. Subjects with active central nervous system disease, Karnofsky performance status <70%, grade 3 or 4 or primary myelofibrosis, or suitable related donors were excluded. Enrollment required a single cord blood unit containing >10(7) nucleated cells per kilogram of recipient weight and matched at > or =4 HLA-A and -B (low or intermediate resolution) and -DRB1 (high resolution) types. Thirty-four subjects were entered, with a median age of 34.5 years (range, 18.2-55 years). Most subjects (n = 23) had a 4 of 6 match, 10 subjects had a 5 of 6 match, and 1 subject had a 6 of 6 match. Diagnoses at transplantation included acute myelogenous leukemia (n = 19), acute lymphoblastic leukemia (n = 9), chronic myelogenous leukemia (n = 3), myelodysplastic syndrome (n = 1), paroxysmal nocturnal hemoglobinuria (PNH) (n = 1), and non-Hodgkin lymphoma (n = 1); 94% were classified as poor risk according to National Marrow Donor Program criteria. Subjects received total body irradiation/cyclophosphamide (n = 27) or busulfan/melphalan (n = 7) conditioning regimens. Four subjects died before CBT and are described here but are not included in the main analysis. The cumulative incidence rates and median times to neutrophil (500/microL) and platelet (>20,000/microL) engraftment were 0.66 by day 42 (median, 31 days) and 0.35 by day 180 (median, 117 days). The cumulative incidence rate for grade II-IV GVHD was 0.34 by day 100. For the primary end point, survival at 180 days, Kaplan-Meier survival estimates were 0.30 (95% confidence interval, 0.14-0.46) by day 180 after transplantation. To date there are 2 survivors, and both are >36 months from enrollment. A retrospective analysis was performed by using high-resolution HLA-A and -B typing, which revealed that approximately one third of subjects had 1 or more additional HLA mismatches compared with results of low- or intermediate-resolution HLA typing. The findings of high treatment-related mortality and slow engraftment kinetics indicate that CBT should continue to be performed in specialized centers with a research focus on cord blood cells.
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PMID:Umbilical cord blood transplantation in adults: results of the prospective Cord Blood Transplantation (COBLT). 1568 76

Myeloproliferative syndromes (MPSs) are clonal stem cell disorders resulting in excessive proliferation of one or more cell lineages. Since MPSs in children occur much less commonly than adults, one can argue that the biology and the categories of the various pediatric MPSs seem to be different from adults. Furthermore, confusion exists between pediatric MPS and other overlapping conditions, such as myelodysplastic syndrome. The authors' objectives were to develop a classification system with a list of disorders relevant to children and to characterize pediatric cases of MPS that were devised according to this classification. Based on the predominant proliferating cell lineage, the authors established a classification system for childhood MPS. Primary MPS was classified into granulocytic proliferation--chronic myelogenous leukemia (CML); monocytic--juvenile myelomonocytic leukemia (JMML); megakaryocytic--essential thrombocythemia (ET), familial thrombocytosis, transient myeloproliferative disorder of Down syndrome (TMD); erythrocytic--polycythemia vera, familial erythrocytosis; fibroblastic--idiopathic myelofibrosis (IMF); eosinophilic--idiopathic hypereosinophilic syndrome (IHES); and mast cells--mastocytosis. Secondary MPS was classified as non-clonal proliferation (eg, infections, drugs, toxins, autoimmune, non-hematologic neoplasm, and trauma), and these were excluded from the study. Next, the classification system was applied to the patient population at the authors' institution. One hundred two cases with primary MPS were identified between 1970 and 2001. Patients were evaluated for clinical manifestations, blood and bone marrow parameters, cytogenetics, and survival following different treatment modalities. Significant proportions of cases of childhood MPS (60%) were unique to the pediatric population and not seen in adults. The most common disorders were JMML (n = 31), TMD of Down syndrome (n = 30), and CML (n = 30); the other disorders were rare: four cases of ET, two of IMF, two of IHES, two of mastocytosis, and one primary erythrocytosis. In contrast to adults, MPS in children is more frequently treated with hematopoietic stem cell transplantation (HSCT), the only available curative option for most of these diseases. HSCT was particularly successful in the more recent cases due to more advanced techniques for HSCT. The authors found that all the cases could be easily classified. MPS in children is different from adult-type MPS in terms of biology, categories, classification, and prognosis.
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PMID:A basic classification and a comprehensive examination of pediatric myeloproliferative syndromes. 1702 36

A somatic mutation in the JH2 autoinhibitory domain of the Janus kinase 2 (JAK2) tyrosine kinase was recently described in polycythemia vera, essential thrombocythemia, and myelofibrosis with myeloid metaplasia. The prevalence of this mutation in either "atypical" myeloproliferative disorders (MPDs) or the myelodysplastic syndromes (MDSs) is unknown. Bone marrow-derived genomic DNA from 245 patients--119 with chronic myelomonocytic leukemia (CMML), 101 with MDS, 11 with hypereosinophilic syndrome (HES), 8 with systemic mastocytosis (SM), and 6 with chronic neutrophilic leukemia (CNL)--was screened for the JAK2 V617F mutation. A mutant allele was detected in 11 patients: 3 with CMML (3%), 5 with MDS (5%), 2 with SM, and 1 with CNL. Interestingly, one of the patients with SM and the patient with CNL with JAK2 V617F had a history of lymphoma, and this patient with SM also had associated myelofibrosis and CMML. The current observation strengthens the specific association between JAK2 V617F and classic MPD, but also suggests an infrequent occurrence in other myeloid disorders.
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PMID:The JAK2 V617F activating tyrosine kinase mutation is an infrequent event in both "atypical" myeloproliferative disorders and myelodysplastic syndromes. 1586 Jun 61

Myeloproliferative disorders (MPD) represent a subcategory of hematological malignancies and are characterized by a stem cell-derived clonal proliferation of myeloid cells including erythrocytes, platelets, and leucocytes. Traditionally, the term 'MPD' included chronic myeloid leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis with myeloid metaplasia (MMM). At present, these four disorders are referred to as 'classic' MPD and are distinguished from a spectrum of other MPD-like clinicopathologic entities that are operationally classified as 'atypical' MPD. The oncogenic mutations(s) in classic MPD are unknown except for CML, which is associated with an activating mutation (Bcr/Abl) of the gene encoding for the Abl cytoplasmic protein kinase (PTK). In the last 3 months, a somatic point mutation of JAK2 (JAK2(V617F)), the gene encoding for another cytoplasmic PTK was reported in the majority of patients with PV and approximately half of those with either ET or MMM. The same mutation was also found in a small number of patients with either atypical MPD or the myelodysplastic syndrome but not in normal controls, germline tissue including T lymphocytes, and patients with secondary erythrocytosis. In vitro, JAK2(V617F) was associated with constitutive phosphorylation of JAK2 and its downstream effectors as well as induction of erythropoietin hypersensitivity in cell lines. In vivo, murine bone marrow transduced with a retrovirus containing JAK2(V617F) induced erythrocytosis in the transplanted mice. Taken together, these observations suggest that JAK2(V617F) is an acquired myeloid lineage-specific mutation that engenders a pathogenetic relevance for the PV phenotype in MPD.
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PMID:JAK2 in myeloproliferative disorders is not just another kinase. 1597 Jul 5


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