Primary polycythemia

Polycythemia is usually defined as a hematocrit above 0.50 in males and 0.47 in females. Polycythemia rubra vera or primary polycythemia, a myeloproliferative disorder, may be complicated by TIAs, ischemic stroke or intracranial venous thrombosis (Silverstein et at 1962 Pearson and Wetherley-Mein 1978 Markus and Hambley 1998). Ischemic complications may occur because the platelet count is raised and platelet activity enhanced, or... 

Polycythemia is characterized by an increase in the number, and in the hemoglobin content, of circulating red cells. In patients who have chronic anoxia from impaired pulmonary ventilation or congenital or acquired heart disease, the increase in plasma erythropoietin leads to secondary polycythemia. Some renal cell carcinomas, hepatocarcinomas, and other tumors, which produce physiologically inappropriate amounts of erythropoietin, may also cause secondary polycythemia. Conversely, anemia can result from renal insufficiency and from chronic disorders that depress erythropoietin production. In polycythemia vera (primary polycythemia), which is a malignancy of erythrocyte stem cells of unknown cause, erythropoietin levels are normal or depressed. 

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. 

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). 

Pearson TC, Wetherley-Mein G (1978). Vascular occlusive episodes and venous hematocrit in primary proliferative polycythemia. Lancet ii 1219-1222 Powers WJ (1986). Should lumbar puncture be part of the routine evaluation of patients with cerebral ischemia Stroke 17 332-333 Prior AL, Wilson LA, Gosling RG et al. (1979). Retrograde cerebral embolism. Lancet ii 1044-1047... 

Allopurinol (zyloprim, aloprim, others) is available for oral use and provides effective therapy for the primary hyperuricemia of gout and the hyperuricemia secondary to polycythemia vera, myeloid metaplasia, other blood dyscrasias, or acute tumor lysis syndrome. 

It is also quite effective in the treatment of polycythemia vera and primary thrombocytocytosis. ... 

Bishop, C., Gamer, W., and Talbott, J.H. Pool size, turnover rate, and rapidity of equilibration of injected isotopic uric acid in normal and pathological subjects. J. Clin. Invest., 30 879,1951. Yu, T.-F., Weissmann, B., Shamey, L., Kupfer, S., and Gutman, A.B. On the biosynthesis of uric acid from glycine- NS in primary and secondary polycythemia. Am. J. Med., 21 901, 1956. Laster, L., and Muller, A.F. Uric acid production in a case of myeloid metaplasia associated with gouty arthritis, studied with N -labeled glycine. Am. J. Med., 15 857,1953. 

The hyperpurine productive character of his gout was confirmed by the 3.3% incorporation of 14 C-glycine into the urinary uric acid and the shape of the output curve (Fig.l). This patient suffered from primary gout (there was no renal failure, obesity, intoxication or polycythemia). 

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