ABSTRACT
Introduction 112 Antiphospholipid syndrome 112 Myeloproliferative disease 119
Plasma coagulation factor concentrations and risk of thrombosis 122
References 122
A prothrombotic state or ‘acquired thrombophilia’ is a feature of a range of diseases and treatments. Well recognized examples are cancer and its treatment and use of the combined oral contraceptive, hormone replacement therapy, and ovarian stimulation therapy. These are considered elsewhere in this volume. This chapter focuses on antiphospholipid syndrome and the myeloproliferative disease essential thrombocythemia. In both conditions thrombosis is the principal clinical manifestation and there are special considerations in relation to pregnancy. Also, there is increasing evidence that increased plasma concentrations of several of the coagulation factors confer a risk of thrombosis. Although there appears to be a heritable component, environmental and lifestyle factors influence clotting factor levels and this type of heritable thrombophilia is also considered here.
