Skip to Main Content

INTRODUCTION

  • Risk factors for thromboembolism may be genetic and acquired (Table 88–1).

  • Hereditary thrombophilia is a genetically determined increased risk of thrombosis.

  • Up to 50% of patients presenting with a first deep venous thrombosis will have an abnormal laboratory test suggesting a thrombophilic defect, and patients with recurrent thromboses or with a strong family history are even more likely to have laboratory evidence of a thrombophilic state (Table 88–2).

  • Up to 16% of patients with thrombophilia have inherited more than one abnormality.

  • These inherited defects also interact frequently with acquired risk factors, such as inactivity, trauma, malignancy, or oral contraceptive use, to lead to clinical thrombosis.

TABLE 88–1THROMBOPHILIAS AND PREDISPOSING RISK FACTORS FOR VENOUS THROMBOEMBOLISM
TABLE 88–2FREQUENCY OF THROMBOPHILIAS IN HEALTHY SUBJECTS AND UNSELECTED AND SELECTED PATIENTS WITH VENOUS THROMBOSIS

HEREDITARY RESISTANCE TO ACTIVATED PROTEIN C

Etiology and Pathogenesis

  • Activated protein C (APC) resistance is an abnormally reduced anticoagulant response of a patient’s plasma that, in more than 90% of cases, ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.