Antithrombin Deficiency Differential Diagnoses

Updated: Aug 22, 2019
  • Author: Bryan A Mitton, MD, PhD; Chief Editor: Perumal Thiagarajan, MD  more...
  • Print

Diagnostic Considerations

A thorough history, including a family history and physical examination, should be performed on patients who have had an episode of deep venous thrombosis (DVT), especially if it was not associated with a prolonged period of little movement or sitting (eg, extended plane flights or car rides). Their diagnostic workup should include deficiencies or mutations of clotting factors, as noted below.

The following should also be considered in the differential diagnosis for a heritable cause of thrombosis:

  • Heparin cofactor II (HCII) deficiency

  • Homozygous MTHFR C677T mutation

  • Hyperhomocysteinemia

  • Abnormal protein Z or protein Z protease inhibitor

  • Activated protein C (APC) resistance (factor V Leiden mutation)

  • Histidine-rich glycoprotein (alpha1 – acid-rich glycoprotein)

  • Possible tissue factor pathway (TFPI) mutations/deficiency

  • Rare inherited defects in the fibrinolytic system (dysplasminogenemia, abnormal PAI-1, defective release of tissue-type plasminogen activator [tPA]) and elevated levels of alpha2-antiplasmin

  • Thrombomodulin gene mutations

Other processes that require consideration in patients who experience thromboembolism include the following acquired causes of antithrombin deficiency and thrombophilia:

Differential Diagnoses