Thrombocytosis, essential

Its primary indications are myeloproliferative disorders, including chronic granulocytic leukemia, polycythemia vera, and essential thrombocytosis. It is also used in combination with radiotherapy for head and neck cancer and for carcinoma of the cervix. Hydroxycarbamide is well absorbed after oral administration. It is in part metabolized in the liver and also excreted unchanged in the urine its elimination half-life is 2-5 hours. Its major toxicity consists of short lasting bone marrow depression. 

It is indicated in treatment of chronic granulocytic leukaemia, polycythemia vera, essential thrombocytosis, melanoma. 

Platelet counts above 400,000/pil are referred to as thrombocytosis, Thrombocytosis is classified as being either primary or secondary, Primary thrombocytosis or essential thrombo-cythemia is associated with chronic myeloproliferative disorders such as chronic myeloid leukemia, polycythemia vera, and agnogenic myeloid metaplasia. Exclusion-based diagnosis of essential thrombocythemia is made when patients... 

Essential thrombocythemia, or idiopathic primary thrombocytosis, is another myeloproliferative disorder in which the platelet count is raised, usually to over 1000 x lO cells/1. Secondary thrombocytosis occurs in malignancy, splenectomy, hyposplenism, surgery, trauma, hemorrhage, iron deficiency, infections, polycythemia rubra vera, myelofibrosis and the leukemias. There is a tendency for arterial and venous thrombosis and, paradoxically, intracranial hemorrhage because the platelets are hemostatically defective (ArboLx et al. 1995 Harrison et al 1998 Mosso et al. 2004 Ogata et al 2005). 

Anagrelide is an oral agent which inhibits platelet aggregation but at lower doses it lowers platelet counts in man due to a marked effect on megakaryocyte maturation. It is nonmutagenic and effectively controls thrombocytosis in PRV and essential thrombocythaemia (ET). Adverse effects are cardiovascular headache, forceful heartbeats, fluid retention and arrhythmias. 

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-... 

Antiphospholipid syndrome (59) Antithrombin III deficiency Essential thrombocytosis Factor V mutation (39)... 

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. 

The opposite phenomenon, elevated platelet count or thrombocytosis, is diagnosed when counts are greater than 400 000 mm There are many causes of thrombocytosis, including primary (e.g., essential... 

Hydroxyurea, an antimetabolite with antineoplastic properties (60 to 80 mg/kg p.o. for a minimum of six weeks), is used in the treatment of melanoma chronic myelocytic leukemia recurrent, metastatic, or inoperable ovarian cancer squamous cell carcinoma of the head and neck polycythemia vera and essential thrombocytosis (see also Figure 15). 

Chronic myelogenous leukemia polycythemia vera essential thrombocytosis... 

Essential thrombocytosis/ polycythemia rubra vera TIMP-1 Serum/High... 

Patients with agnogenic myeloid metaplasia, essential thrombocytosis, and polycythemia vera had been reported to have increased plasma TIMP-1 levels. An inverse correlation was demonstrated between marrow fibrosis in patients with agnogenic myeloid metaplasia and plasma MMP-3 levels (W2). 

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