hematology and oncology
Overview of Thrombotic Disorders
Diagnosis of Thrombotic Disorders
Diagnostic evaluations of thrombotic disorders are summarized elsewhere in THE MANUAL specific to the location of the thrombus (eg, Deep Venous Thrombosis (DVT) , Predisposing factors should always be considered. In some cases, the condition is clinically obvious (eg, recent surgery or trauma, prolonged immobilization, cancer, infection, medical illness, generalized atherosclerosis). If no predisposing factor is readily apparent, further evaluation should be considered in patients with A family history of venous thrombosis (first-degree relative with venous thromboembolism before age 50 years) More than one episode of venous thrombosis Venous or arterial thrombosis before age 50 years Unusual sites of venous thrombosis (eg, cavernous sinus, splanchnic veins) As many as half of all patients with spontaneous DVT have a genetic predisposition. However, in many such instances, identification of an inherited thrombophilic state does not influence therapy. Therefore, society guidelines suggest targeted testing in patients at high risk of inherited thrombophilia ( Diagnosis references ). Testing for predisposing congenital and acquired factors includes specific assays that measure the quantity or activity of natural anticoagulant molecules in plasma, and screening for specific gene defects, as follows: Clotting assay for lupus anticoagulant Clotting assay for resistance to activated protein C Genetic test for factor V Leiden Genetic test for prothrombin gene mutation (G20210A) Factors VIII, IX, and XI activity Functional assay of antithrombin Functional assay of protein C Functional assay of protein S Antigenic assays of total and free protein S. Measurement of plasma homocysteine levels Immunoassays for antiphospholipid antibodies 1.National Institute on Health and Care Excellence (NICE): Venous thromboembolic diseases: diagnosis, management and thrombophilia testing. NICE guideline [NG 158]. March 26, 2020. 2.Ortel TL, Neumann I, Ageno W, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism.Blood Adv2020;4(19):4693-4738. doi:10.1182/bloodadvances.2020001830 