title: Do we need antiplatelet therapy in thrombocytosis? Pro. Diagnostic and pathophysiologic considerations for a treatment choice.
abstract: Thrombocytosis (defined as platelets >450 x 109/l) has several aetiologies. After having excluded spurious thrombocytosis (e. g., due to microspherocytes, schistocytes, cryoglobulins, or bacteria), the differential diagnosis of true thrombocytosis encompasses secondary causes (as diverse as inflammation, infection, malignancy, iron deficiency, or asplenia), primary hereditary (rare forms of familial thrombocytosis) and primary acquired entities (either in the context of a myelodysplastic syndrome or more frequently a myeloproliferative neoplasia). This manuscript addresses the following aspects: 1) diagnostic approach to thrombocytosis; 2) various mechanisms leading to a high platelet count; 3) potential of some of these mechanisms to modulate platelet function, producing hyper-reactive platelets and thus exerting a direct impact on the thrombotic risk; 4) indication of anti-thrombotic treatment in patients with thrombocytosis. There is a single prospective randomized clinical trial showing the benefit of acetyl-salicylic acid in polycythaemia vera. For other types of primary thrombocytosis and for secondary forms, treatment decisions have to be individualized according to the patient thrombotic and bleeding risks, taking into account the mechanism causing thrombocytosis. This manuscript discusses experimental and clinical data suggesting that besides patients with essential thrombocythaemia and other forms of primary thrombocytosis also those with thrombocytosis in the context of chronic inflammation, malignancy, or exposure to high altitude might benefit from anti-platelet treatment.
authors.affiliation: Lorenzo Alberio, MD, Service of Hematology and Central Hematology Laboratory, University Hospital of Lausanne, CHUV, Rue du Bugnon 46, 1011 Lausanne, Switzerland, Tel. +41/21/314 11 11; Fax +41/21/314 41 80, E-mail: lorenzo.alberio@chuv.ch.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Alberio
mesh_terms: D000066491:Clinical Decision-Making / Q000379:methods; D019317:Evidence-Based Medicine; D006470:Hemorrhage / Q000139:chemically induced* / Q000517:prevention & control*; D006801:Humans; D018579:Patient Selection; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects*; D012307:Risk Factors; D013922:Thrombocytosis / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors
keywords: Thrombocytosis; hyper-reactive platelets; mechanisms; thrombotic risk