[Thrombocytosis: adverse effect of heparin treatment].
BACKGROUND
Thrombocytosis induced by heparin is rarely reported in the literature.


METHODS
We report here four cases of thrombocytosis, three in patients under treatment for a stable myeloproliferative disorder. Thrombocytosis always regressed when heparin treatment was discontinued, and no thrombotic events occurred.


CONCLUSIONS
Following several reports suggesting an association between heparin and thrombocytosis, the French adverse drug reporting (pharmacovigilance) network identified 51 cases. Thrombocytosis associated with heparin is probably explained by the latter's potentiation of megakaryocytopoiesis, in particular, by inhibition of platelet factor 4 (PF4). Thrombocytosis is a further reason to monitor platelet counts during heparin treatment.
Camou
Fabrice
F
Clinique de médecine interne et maladies infectieuses, CHU Haut-Lévêque, Pessac. fabrice.camou@chu-bordeaux.fr
Viallard
Jean-François
JF
Caubet
Olivier
O
Pellegrin
Jean-Luc
JL
D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects*; D017984:Enoxaparin / Q000009:adverse effects; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects*; D005500:Follow-Up Studies; D005602:France; D006493:Heparin / Q000009:adverse effects*; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects; D006801:Humans; D008297:Male; D009196:Myeloproliferative Disorders / Q000188:drug therapy; D010976:Platelet Count; D010978:Platelet Factor 4 / Q000037:antagonists & inhibitors; D013922:Thrombocytosis / Q000139:chemically induced*; D034061:Thrombopoiesis / Q000187:drug effects; D013997:Time Factors; D000078222:Tinzaparin
D000925:Anticoagulants; D017984:Enoxaparin; D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; D010978:Platelet Factor 4; D000078222:Tinzaparin; D006493:Heparin