Antithrombin Deficiency Differential Diagnoses

Updated: Jul 29, 2022
  • Author: Drew H Barnes, MD; Chief Editor: Perumal Thiagarajan, MD  more...
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Diagnostic Considerations

A thorough history, including family history, as well as a detailed physical examination, should be performed on patients with deep venous thrombosis (DVT), especially if it was not associated with prolonged immobility (eg, extended plane flights or car rides). The diagnostic workup should include assessment for deficiencies or mutations of clotting factors, as noted below.

The following should 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 plasminogen activator–1 [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 AT deficiency and thrombophilia:

Differential Diagnoses