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ALL / Haematology
Thrombocytosis
Thrombocytosis
Thrombocytosis is an abnormally high platelet count, usually > 400 * 109/l.Causes of thrombocytosis
- reactive: platelets are an acute phase reactant - platelet count can increase in response to stress such as a severe infection, surgery. Iron deficiency anaemia can also cause a reactive thrombocytosis
- malignancy
- essential thrombocytosis (see below), or as part of another myeloproliferative disorder such as chronic myeloid leukaemia or polycythaemia rubra vera
- hyposplenism
Essential thrombocytosis
Essential thrombocytosis is one of the myeloproliferative disorders which overlaps with chronic myeloid leukaemia, polycythaemia rubra vera and myelofibrosis. Megakaryocyte proliferation results in an overproduction of platelets.
Features
- platelet count > 600 * 109/l
- both thrombosis (venous or arterial) and haemorrhage can be seen
- a characteristic symptom is a burning sensation in the hands
- a JAK2 mutation is found in around 50% of patients
Management
- hydroxyurea (hydroxycarbamide) is widely used to reduce the platelet count
- interferon-α is also used in younger patients
- low-dose aspirin may be used to reduce the thrombotic risk
+PassMedicine Notes
Thrombocytosis is an abnormally high platelet count, usually > 400 * 109/l.
Causes of thrombocytosis- reactive: platelets are an acute phase reactant - platelet count can increase in response to stress such as a severe infection, surgery. Iron deficiency anaemia can also cause a reactive thrombocytosis
- malignancy
- essential thrombocytosis (see below), or as part of another myeloproliferative disorder such as chronic myeloid leukaemia or polycythaemia rubra vera
- hyposplenism
Essential thrombocytosis
Essential thrombocytosis is one of the myeloproliferative disorders which overlaps with chronic myeloid leukaemia, polycythaemia rubra vera and myelofibrosis. Megakaryocyte proliferation results in an overproduction of platelets.
Features- platelet count > 600 * 109/l
- both thrombosis (venous or arterial) and haemorrhage can be seen
- a characteristic symptom is a burning sensation in the hands
- a JAK2 mutation is found in around 50% of patients
- hydroxyurea (hydroxycarbamide) is widely used to reduce the platelet count
- interferon-#alpha# is also used in younger patients
- low-dose aspirin may be used to reduce the thrombotic risk
