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Query: UMLS:C0032463 (polycythemia vera)
 3,374 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present paper describes the case of a patient who developed a B-cell chronic lymphocytic leukemia (B-CLL) 15 months after the diagnosis of polycythemia vera, which had been treated only with phlebotomies. In spite of lymphocytosis and the clinical signs and symptoms of leukemia, the patient exhibited at the same time presumptive elements of polycythemia (high LAP index levels, a high number of neutrophils). Cytogenetic investigations, carried out after the appearance of B-CLL, revealed the presence of an unusual abnormality (18 p+) both in bone marrow not stimulated by mitogens and in PWM-stimulated circulating lymphocytes. This case, which is the ninth of its kind described in the literature, offers some interesting observations about the association between myeloproliferative and lymphoproliferative syndromes.
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PMID:Chronic lymphocytic leukemia (B-cell) in the course of polycythemia vera. Description of a case with an unusual chromosomic anomaly. 332 9

Thrombohemorrhagic complications are a major cause of morbidity and mortality in patients with essential thrombocythemia (ET) and polycythemia vera (PV). The pathogenesis of these complications is not completely clarified. Several studies have described abnormalities of red blood cells and platelets in these patients. However, no studies are available on changes in the polymorphonuclear leukocytes (PMNs), which can play an important role in the activation of the hemostatic system. In patients with ET (n = 37) and PV (n = 34), a series of PMN activation parameters (PMN membrane CD11b and leukocyte alkaline phosphatase [LAP] antigen expression, cellular elastase content, plasma elastase, and myeloperoxidase levels) was evaluated simultaneously with the levels of plasma markers of endothelial damage (thrombomodulin and von Willebrand factor antigen) and hypercoagulation (thrombin-antithrombin complex, prothrombin fragment 1 + 2, and D-dimer). The results show the occurrence of PMN activation in both groups of patients compared with a control group of healthy subjects. An increase in CD11b and LAP expression by PMN membrane was observed, together with a significant increase in cellular elastase content, plasma elastase, and myeloperoxidase levels. In addition, patients had high plasma levels of endothelial and hypercoagulation markers compared with controls. For the first time, these data show that in ET and PV, 2 hematologic conditions that place patients at increased risk for thrombosis, an in vivo leukocyte activation occurs and is associated with laboratory signs of endothelium and coagulation system activation. (Blood. 2000;96:4261-4266)
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PMID:Polymorphonuclear leukocyte activation and hemostasis in patients with essential thrombocythemia and polycythemia vera. 1111 Jul

Diagnosis of essential thrombocythemia (ET) has been usually established by regarding the criteria of the Polycythemia Vera Study Group. Accordingly, a retrospective clinicopathological study was performed on 120 patients with a follow-up ranging between 5 and 13 years and repeated bone marrow trephine examinations. Following the new WHO classification, at presentation patients revealed three distinctive patterns of bone marrow (BM) features: (true) ET in 43 patients, prefibrotic idiopathic myelofibrosis (IMF) in 50 patients, and early IMF in 27 patients. Heterogeneity of morphological features was associated with correspondingly expressed laboratory data. Contrasting initial and early IMF, patients with true ET displayed an about 80% probability to lack splenomegaly, anemia, and increase in the LDH and LAP values and also failed to show any myeloblasts or erythroblasts on the peripheral blood films. Follow-up examinations including sequential BM biopsies (mean interval 39 +/- 31 months) disclosed that of the 43 patients with true ET only one developed an increase in reticulin. On the other hand, 65 of 77 patients with prefibrotic and early IMF evolved into overt myelofibrosis-osteosclerosis. Moreover, survival analysis demonstrated significant differences in our patients. A neglectable proportion of life loss according to a sex- and age-matched general population was found in true ET (less than 11%) opposed to IMF without or mild fibrosis (range 21% to 32%).
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PMID:Follow-up examinations including sequential bone marrow biopsies in essential thrombocythemia (ET): a retrospective clinicopathological study of 120 patients. 1221 Aug 9

The clinical criteria according to the Polycythemia Vera Study Group (PVSG) do not distinguish between essential thrombocythemia (ET), thrombocythemia associated with early-stage polycythemia vera (PV) and prefibrotic chronic idiopathic myelofibrosis (CIMF). The criteria only classify the advanced stage of PV with increased red cell mass. The classification of myeloproliferative disorders (MPDs), proposed by the World Health Organization (WHO) in 2001, is a compromise of the clinical PVSG and WHO bone marrow criteria, and excludes early stages of ET and PV. The updated European clinical and pathological criteria combine the WHO bone marrow criteria with established and new clinical, laboratory, biological, and molecular MPD markers. This allows clinicians and pathologists to diagnose early-stage MPD and to differentiate ET, PV, and prefibrotic chronic idiopathic myelofibrosis (CIMF). Depending on laboratory tests and diagnostic criteria used, the population of the MPD patients defined as ET, PV, and CIMF are heterogeneous at the clinical, laboratory, and biological and pathological levels. The recent discovery of the JAK2 V617F mutation, which is the cause of a distinct trilinear MPD in its manifold clinical manifestations during long-term follow-up, increases the specificity of a positive JAK2 V617F polymerase chain reaction (PCR) test for the diagnosis of MPD (near 100%), but only half of the ET and CIMF patients according to the PVSG (sensitivity 50%) and the majority of PV patients (sensitivity 95%) are JAK2 V617F positive. A comparison of the laboratory features of JAK2 V617-positive and JAK2 wild-type ET patients clearly showed that JAK2 V617-positive ET is characterized by higher values for hemoglobin, hematocrit, and neutrophil counts; lower values for serum erythropoietin (EPO) levels, serum ferritin, and mean corpuscular volume; and by increased cellularity of the bone marrow in biopsy material. This indicates that JAK2 V617-positive ET patients, diagnosed according to the PVSG criteria, represent a "forme fruste of PV" consistent with early PV mimicking ET (JAK2 V617F trilinear MPD). In contrast, the JAK2 wild-type ET patients had significantly higher platelet counts and usually had a clinical picture of ET with normal serum EPO levels, PRV-1 expression, and leukocyte alkaline phosphatase score, and a typical WHO ET bone marrow picture. The clinical and pathological data on JAK2 V617F-positive MPD patients suggest that the JAK2 V617F mutation defines one disease entity with several sequential steps of ET, PV, and secondary myelofibrosis during long-term follow-up, and that the wild-type JAK2 MPDs may represent another distinct entity with a related but different molecular etiology. MPD-specific markers such as serum EPO, endogenous erythroid colony formation (EEC), and JAK2 V617F have high specificities, but the sensitivities are not high enough to detect the early stages of the MPDs, ET, PV, and prefibrotic CIMF. Bone marrow histopathology in addition to clinical, laboratory, biological, and molecular markers, including the JAK2 V617 PCR test, serum EPO, PRV-1, EEC, LAP score, peripheral blood parameters, and spleen size on echogram will detect the early stages of MPD and allows diagnostic differentiation of the three primary MPDs (ET, PV, and CIMF) in both JAK2 V617F-positive and JAK2 wild-type MPD patients.
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PMID:The 2001 World Health Organization and updated European clinical and pathological criteria for the diagnosis, classification, and staging of the Philadelphia chromosome-negative chronic myeloproliferative disorders. 1681 Jun 9