Thrombocytosis is the presence of high platelet counts in the blood, and can be either reactive or primary (also termed essential and caused by a myeloproliferative disease). Although often symptomless (particularly when it is a secondary reaction), it can predispose to thrombosis in some patients. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... A 250 ml bag of newly collected platelets. ... Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... The myeloproliferative diseases are a group of diseases of the bone marrow where excess cells are produced. ... Thrombosis is the formation of a clot or thrombus inside a blood vessel, obstructing the flow of blood through the circulatory system. ...

Generally, a normal platelet count ranges from 150,000 and 450,000 per mm³. These limits, however, are determined by the 2.5th lower and upper percentile, and a deviation does not necessary imply any form of disease. Nevertheless, counts over 750,000 (and especially over a million) are considered serious enough to warrant investigation and intervention. In descriptive statistics, the pth percentile is a scale value for a data series equal to the p/100 quantile. ...

Signs and symptoms

High platelet levels do not necessarily signal any clinical problems, and are picked up on a routine full blood count. However, it is important that a full medical history be elicited to ensure that the increased platelet count is not due to a secondary process. Often, it occurs in tandem with an inflammatory disease, as the principal stimulants of platelet production (e.g. thrombopoietin) are elevated in these clinical states as part of the acute phase reaction. A full blood count (FBC) or complete blood count (CBC) is a test requested by a doctor or other medical professional that gives information about the cells in a patients blood. ... Inflammation is the first response of the immune system to infection or irritation and may be referred to as the Innate immune system and as healthy nor unhealthy on its own: Inflammation helps fight disease, but it comes at the cost of suspending the bodys normal immune and catabolic... Thrombopoietin is the recently discovered (1994) glycoprotein hormone that regulates the production of platelets. ... Acute phase proteins are a class of proteins that are synthetized in the liver in response to inflammation. ...

High platelet counts can occur in patients with polycythemia vera (high red blood cell counts), and is an additional risk factor for complications. Polycythemia is a condition in which there is a net increase in the total circulating erythrocyte (red blood cell) mass of the body. ... Human red blood cells Red blood cells are the most common type of blood cell and the vertebrate bodys principal means of delivering oxygen from the lungs or gills to body tissues via the blood. ...

A very small segment of patients report symptoms of erythromelalgia, a burning sensation and redness of the extremities that resolves with cooling and/or aspirin use. Erythromelalgia, also known as Mitchells disease (after Silas Weir Mitchell) and red neuralgia, is a rare disorder in which blood vessels, usually in the extremities and especially in the feet, are blocked and inflamed, causing a painful burning and throbbing sensation and red skin. ... Aspirin or acetylsalicylic acid (acetosal) is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ...

Diagnosis

Laboratory tests might include: full blood count, liver enzymes, renal function and erythrocyte sedimentation rate. A full blood count (FBC) or complete blood count (CBC) is a test requested by a doctor or other medical professional that gives information about the cells in a patients blood. ... Liver function tests (LFTs or LFs), are groups of clinical biochemistry laboratory blood assays designed to give a doctor or other health professional information about the state of a patients liver. ... In medicine (nephrology) renal function is an indication of the state of the kidney and its role in physiology. ... The erythrocyte sedimentation rate(ESR), also called a sedimentation rate, sed rate or Biernacki Reaction, is a non-specific measure of inflammation that is commonly used as a medical screening test. ...

If the cause for the high platelet count remains unclear, bone marrow biopsy is often undertaken, to differentiate whether the high platelet count is reactive or essential. Grays Anatomy illustration of cells in bone marrow. ... Brain biopsy A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ...

Causes

Increase platelet counts can be due to a number of disease processes:

• Essential (primary)
  • Essential thrombocytosis (a form of myeloproliferative disease)
  • Other myeloproliferative disorders such as chronic myelogenous leukemia, polycythemia vera, myelofibrosis
• Reactive (secondary)
  • Inflammation
  • Surgery (which leads to an inflammatory state)
  • Hyposplenism (decreased breakdown due to decreased function of the spleen)
  • Hemorrhage and/or iron deficiency

Essential thrombocytosis (ET, essential thrombocythemia) is a rare chronic blood disorder characterized by the overproduction of platelets by megakaryocytes (the precursor cell for platelets) in the absence of an alternative cause. ... The myeloproliferative diseases are a group of diseases of the bone marrow where excess cells are produced. ... The myeloproliferative diseases are a group of diseases of the bone marrow where excess cells are produced. ... Chronic myelogenous leukemia (CML) is a form of chronic leukemia characterized by increased and unregulated clonal production of predominantly myeloid cells in the bone marrow. ... Polycythemia is a condition in which there is a net increase in the total circulating erythrocyte (red blood cell) mass of the body. ... Myelofibrosis, one of the myeloproliferative diseases, is the gradual replacement of the bone marrow by connective tissue. ... Asplenia refers to the absence (a-) of normal spleen function and is associated with some risks. ... The spleen is an organ of the lower abdomen, where it functions in the destruction of old red blood cells and holding a reservoir of blood. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Iron deficiency can refer to: Iron deficiency (plant disorder) Iron deficiency (medicine) This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

Treatment

Often, no treatment is required or necessary for reactive thrombocytosis.

However, in primary thrombocytosis, if platelet counts are over 750,000 or 1,000,000, and especially if there are other risk factors for thrombosis. Aspirin at low doses is thought to be protective, and extreme levels are treated with hydroxyurea (a cytoreducing agent). The new agent anagrelide (Agrylin®) has recently been introduced for the treatment of essential thrombocytosis. However, recent studies show that anegrilide is not significantly more effective than traditionally used hydroxyurea (Harrison et al 2005). Aspirin or acetylsalicylic acid (acetosal) is a drug in the family of salicylates, often used as an analgesic (against minor pains and aches), antipyretic (against fever), and anti-inflammatory. ... Hydroxyurea chemical structure Hydroxyurea or hydroxycarbamide (rINN), (brand names include Hydrea®) is an antineoplastic drug used in hematological malignancies. ... Anagrelide (Agrylin®/Xagrid®, Shire) is a drug used for the treatment of essential thrombocytosis (ET; essential thrombocythemia). ...

Reference

• Harrison CN, Campbell PJ, Buck G, Wheatley K, East CL, Bareford D, Wilkins BS, van der Walt JD, Reilly JT, Grigg AP, Revell P, Woodcock BE, Green AR; United Kingdom Medical Research Council Primary Thrombocythemia 1 Study. Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia. N Engl J Med 2005;353:33-45. PMID 16000354.