Myeloproliferative syndrom

Patients are initially grouped by independent measurements of red cell mass and plasma volume. Where the latter is contracted the increase in packed red cell volume or haemoglobin in the peripheral blood is spurious or relative. In true erythrocytosis the red cell mass, and often the plasma volume, are both expanded. These individuals are further subdivided, depending upon whether tissue oxygenation is impaired, with consequent activation of normal physiological mechanisms. Conversely, this situation may reflect pathological production of erythropoietin or uncontrolled overgrowth of red cells in the chronic myeloproliferative syndrome. 

Physiologically, this is often reactive due to iron deficiency, bleeding or ongoing inflammation. In contrast the idiopathic, primary of essential variant, preferably known as thrombocythaemia, is a member of the myeloproliferative syndrome where the autonomous production is a neoplastic process. 

The term myeloproliferative syndrome encompasses the following (1.) chronic myeloid leukaemia, (2.) idiopathic osteomyelofibrosis and sclerosis, (3.) polycyth-aemia vera, and (4.) essential thrombocytosis. Inter-... 

The presence of greater than normal amounts of thrombocytes in the circulation is known as thrombocytosis and along with reticulocytosis and leukocytosis is a manifestation of increased activity of the hematopoietic system. Zucker and Woodard (Z2) reported a series of 12 patients with thrombocytosis, consisting of two cases of polycythemia vera, three of essential thrombocytemia, three of chronic granulocytic leukemia, one myeloproliferative syndrome, one erythroleukemia, and one cancer of the bladder. The platelet counts ranged from 685 X 10 to 2500 X 10 per cubic millimeter, all much above the upper limit of normal. 

Compared with untreated patients and patients treated with busulfan or hydroxyurea, interferon alfa produced a significantly higher frequency of clonal aberrant cytogenetic abnormalities and chronic clonal evolution in patients with chronic myeloid leukemia (386). However, the possible role of interferon alfa in the secondary occurrence of hematological malignancies is purely speculative. Only isolated cases of myeloproliferative syndrome, leukemia, or lymphoma have been attributed to interferon alfa (SED-13, 1098) (SEDA-20, 331) (SEDA-21, 373). There was no increased incidence of second cancers in patients treated for hairy cell leukemia (SEDA-20, 331). 

Kurschel E, Metz-Kurschel U, Niederle N, Aulbert E. Investigations on the subclinical and clinical nephrotoxicity of interferon alpha-2B in patients with myeloproliferative syndromes. Ren Fail 1991 13(2-3) 87-93. 

The principal use of HU has been as a myelosuppressive agent in myeloproliferative syndromes, particularly in essential thrombocythemia with platelet counts >1.5 million cells/mrrP or history of arterial or venous thrombosis. It dramatically lowers the risk of thrombosis by lowering the platelet count, through its effect on neutrophil and red cell counts, and by reducing L-selectin expression and increasing NO production of neutrophils. 

Shuai X, Zhou DF, Shen T, Wu Y, Zhang X, Wang X, Li Q. Overexpression of the novel oncogene SALL4 and activation of the Wnt/beta-catenin pathway in myeloproliferative syndrome. Cancer Genet C)nogenet. 2009 194 119-24. 

Reye or Reye-like syndromes H ep ato spl eno megaly Myeloproliferative syndrome Failure to thrive Peculiar smell... 

Chronic, recurrent) pancreatitis Hepatosplenomegaly Reye or "Reye-like syndromes Recurrent severe infections (Non-immune hemolytic) anemia Myeloproliferative syndrome (Cave Routine chemical abnormalities such as hypoglycemia, metabolic acidosis, lactic acidosis, hyperammonemia or ketonuria, the usual concomitants of disorders of organic acid metabolism, can be conspicuously absent in the last two categories)... 

Gilbert-Barness, E. and Harness, L.A. (1999) Isovaleric acidemia with promyelocytic myeloproliferative syndrome. Pediatr. Dev. Pathol. 2, 286-291. 

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