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The incidence of PAH in CMPD is unknown. When present, PAH in CMPD may be attributed to thrombo–embolism, which is a known complication of CMPD. CMPD and unexplained PAH has been reported in few case reports or few studies with limited cases. Pathophysiology may be related to pulmonary capillary obstruction from increased cellular components, platelet activation and aggregation, micro thrombose formation and stasis. We present the case of a middle aged lady with no previous co–morbidity, who presented with polycythaemia and biventricular failure. Evaluation revealed PAH with no evidence of pulmonary thrombo–embolism. Haematocrit, Serum erythropoietin assay and bone marrow analysis suggested polycythaemia vera. Unexplained PAH in CMPD is discussed.
Résumé
Introduction: Microparticles are membrane bound vesicles, measuring less than 1.0 um, which are released during cellular activation or during apoptosis. Studies have shown that these circulating microparticles play a role in coagulation, cell signaling and cellular interactions. Increased levels of circulating microparticles have been observed in a number of conditions where there is vascular dysfunction, thrombosis and inflammation. The objective of this study was to determine the various plasma-derived microparticles in patients with polycythaemia vera (PV) in Universiti Kebangsaan Malaysia Medical Centre and to compare them with normal control. Methods: A total of 15 patients with PV and 15 healthy volunteers were included in this cross-sectional descriptive study. Plasma samples from both patients and healthy volunteers were prepared and further processed for isolation of microparticles. Flow cytometry analyses were then carried out in all samples to determine the cellular origin of the microparticles. Full blood count parameters for both groups were also collected. Data collected were analyzed using SPSS version 12.0. Results: Patients with PV had a significantly higher percentage of platelet derived microparticles compared to healthy controls (P 0.05). Conclusion: The median percentage of positive events for platelet derived microparticles was higher in patients with PV compared to normal healthy controls.
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The discovery of an acquired mutation affecting the gene for janus kinase 2(JAK2 V617F)in a high proportion of patients with polycythaemia vera(PV)represents a major breakthrough in molecular understanding of the PV.This article will review the impact of the JAK2 mutation on the diagnosis and treatment of PV.
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That the suggested criteria for diagnosis of polycythaemia vera (PV) are rather complicated, therefore accurate diagnosis of PV from other types of polycythaemia is needed. Serum Vitamin B12 and Vitamin B12 binding proteins were determined in a patients with PV and other 5 patients with secondary polycythaemia. Both serum Vitamin B12 and unsaturated Vitamin B12 binding capacity (UBBC) increased considerably. TCIII and TCI increased also markedly, i.e., 16 and 8 folds, respectively, resulting in a decreased ratio of TCI/TCIII from the normal value of 1.34 to 0.71. Patients with secondary polycythaemia had slightly increased serum Vitamin B12 while serum UBBC, TCI and TCIII levels showed no significant alteration from those of normal subjects. These findings indicated that not only increased serum Vitamin B12 and UBBC but also an increase of TCIII and the ratio of TCIII/TCI are the positive findings in patients with PV. Therefore determinations of serum Vitamin B12 and its binding proteins can be used as a criteria for the differential diagnosis of PV from secondary polythaemia.
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An 80-year-old woman was admitted to the hospital with of pain in the right upper abdominal region. She had splenomegaly and CT scan showed gall stones and splenic infarction. Blood examination revealed erythrocytosis, raised LAP, elevated serum vitamin B12, vitamin B12 binding proteins and reversed TCI/TCIII ratio. All these findings confirmed the diagnosis of polycythaemia vera. After splenectomy and cholecystectomy, a leucoerythroblastic blood picture with teardrop poikilocytosis was detected in the peripheral blood smear. The haemoglobin concentration decreased but leucocytosis and thrombocytosis still persisted. Bone marrow aspirate showed erythroid hypoplasia, decreased megakaryocytes and some degree of fibrosis. This was compatible with the criterial diagnosis of myelofibrosis with myeloid metaplasia. Blood transfusions and myleran were given. Peritoneal dialysis was performed and the patient had severe bleeding and died from cardiac failure due to septic shock. This patient is an example of the transition from polycythaemia vera to myelofibrosis with myeloid metaplasia.