Information
Editors
Thrombocytosis
Essentials
- The blood platelet or thrombocyte concentration varies between individuals but remains rather constant in each individual. The reference range is 150-360 × 109 /l.
- Thrombocytosis can be classified into two categories: primary thrombocytosis, i.e. thrombocytosis related to myeloproliferative diseases, and secondary or reactive thrombocytosis.
- In addition, it should be kept in mind that the reference range follows the Gaussian curve, i.e. 2.5% of healthy people have platelet levels exceeding the reference range. In most such cases, the platelet level exceeds the upper reference limit only slightly.
- In reactive thrombocytosis, platelets rarely cause problems, and treatment of the underlying disease will correct platelet levels.
Causes of thrombocytosis
- Primary thrombocytoses: myeloproliferative disorders (essential thrombocythaemia Essential Thrombocythaemia (Et), polycythaemia vera Polycythaemia Vera (Pv), chronic myeloic leukaemia Chronic Myelogenous Leukaemia (CML), myelofibrosis Myelofibrosis (Mf))
- Secondary thrombocytoses: acute or chronic haemorrhage, over-compensation in the recovery phase of thrombocytopenia, connective tissue disorders, infections, intense physical exercise, childbirth, iron deficiency, haemolytic anaemia, a sequel of splenectomy, neoplastic diseases, reactions to medications, sequelae of operations
Treatment
- In secondary thrombocytosis, treatment of the primary disease; treatments to lower the platelet count are usually not needed.
- As in myeloproliferative diseases thrombocytosis is associated with an increased risk of thrombosis and bleeding, a haematologist or an internist should be consulted even in cases with no symptoms.
- A haematologist or an internist should be consulted if the cause of thrombocytosis remains unclear.