Polycythemia syndromes

Common risk factors for developing branch retinal vein thrombosis (BRVT) and central retinal vein thrombosis (CRVT) include increased plasma fibrinogen, diabetes, decreased exercise, hypertension, and hyperviscosity (205). Sickle cell anemia, polycythemia vera, and other proliferative disorders may also lead to this syndrome. 

Hepatic venous thrombosis, also known as Budd-Chiari syndrome, is caused by hypercoagulable disorders precipitated by pregnancy, infection, and birth control medication. An acute painful abdomen, sudden enlargement of the liver, and the presence of ascites make up a triad of clinical symptoms that are important in the diagnosis of this syndrome. Myeloproliferative disorders such as polycythemia vera and paroxysmal nocturnal dyspnea were previously thought to be responsible. Factor V Leiden and prothrombin 20210 mutations are also known to be responsible, Other intraabdominal thromboses include portal vein thrombosis, mesenteric vein thrombosis and renal vein thrombosis. 

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. 

Pezzimenti JF, Kim HC, Lindenbaum J. Eiythroleukemia-like syndrome due to busulfan toxicity in polycythemia vera. Cancer 1976 38(6) 2242-6. 

A 70-year-old woman with polycythemia rubra vera and Guillain-Barre syndrome, but no known risk factors for thrombosis, had a cerebral infarction 10 days after receiving intravenous immunoglobulin the authors wondered whether there was a relation to the polycythemia vera (48). 

Small for gestational age-prematurity Respiratory distress syndrome Maternal diabetes meUitus Toxemia of pregnancy Other (e.g., cold stress, polycythemia)... 

Since the original description by Waldenstrom, it has become clear that this syndrome is not confined to raacroglobulinemia, and so it is better called viscosity syndrome. It has been found in some 4% of IgG-inyelomatosis H22), occasionally with IgA paraprotein and even with Bence Jones proteinemia, usually due to polymerization [reviewed by Somer (S19)], and it is also recorded with IgE (01). With regard to viscosity syndromes due to paraproteins the relevant abnormality is detected in viscosity measurements on either whole blood, plasma, or serum (S19) the latter is the most convenient. This is not the case in polycythemia, etc. (W5). 

The BMR is altered in a number of pathological states. The BMR is increased in hyperthyroidism, fever (approximately 12% elevation for each degree Celsius above normal body temperature), Cushing s syndrome, tumors of the adrenal gland, anemia, leukemia, polycythemia, cardiac insufficiency, and injury. BMR is decreased in hypothyroidism, starvation, malnutrition, hypopituitarism, hypoa-drenalism (e.g., Addison s disease), and anorexia nervosa. 

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. 

FORMED ELEMENTS OE BLOOD Glucocorticoids exert minor effects on hemoglobin and erythrocyte content of blood, as evidenced by the occurrence of polycythemia in Cushing s syndrome and of normochromic, normocytic anemia in adrenal insufficiency. More profound effects are seen in the setting of autoimmune hemolytic anemia, in which the immunosuppressive effects of glucocorticoids can diminish erythrocyte destruction. 

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