Test Code: At Preferred Name Anti-thrombin

2 hours
1 week
Medicare Item
2 hours

Test Tubes

ImageSpecimen TypeSpecimen VolumeTube Type
Blood (adult)2.7mL Sodium Citrate 2.7 mL (Solid Pale Blue Top)
Blood (paediatric)1.8 mLSodium Citrate 1.8 mL Paed (Clear/Pale Blue Inner)
Blood (neonate)1.0mlSodium Citrate 1.0 mL Neonate (Pale Blue Top)


If difficulty collecting this amount please contact laboratory. Samples Must arrive and be processed by the Laboratory within 4hrs of collection.
Accurate filling of specimen tube essential.  Please ask the patient what anticoagulants, if any, they are on.
Please ensure private patients fill out Patient Questionnaire for Thrombophilia Screen  for billing purposes. This form ( SI-A136) must accompany request form.  Testing will not proceed without completion of this form.
Specimens must be transported at room temperature to the Laboratory in a red specimen bag ASAP. (Maximum delay to testing laboratory must not exceed 3hrs)


Private patients must fill out Patient Questionnaire for Thrombophilia Screen  (SI-A 136) or an out-of-pocket expense may be incurred.
Q1. Do your parents, siblings or children have any of the following inherited blood clotting conditions (also known as a ‘thrombophilia’)? Please tick any appropriate box.
1/ Antithrombin III deficiency
2/ Protein C deficiency
3/ Protein S deficiency
4/ Activated protein C deficiency
5/ Factor V Leiden mutation or Prothrombin gene mutation
Yes, but unsure which one

Q2. Have you been recently diagnosed with or do you have a history of blood clots in the veins (known as “venous thrombosis”)?
These are most commonly in your lungs (known as a “pulmonary embolism” or “PE”) or legs (known as “deep venous thrombosis” or “DVT”) but can also be in the upper limb veins, cerebral veins, abdominal veins, or other less common veins.


Please note, if the answer to questions 1 and 2 are both no, there will be an out-of-pocket charge for this testing as it is not covered by Medicare. Prices are as follows:
Thrombotic profile $180 (includes tests 1-5 as well as Lupus Anticoagulant)
Tests 1-4 $25 per test ($25 to $100 depending on no. of tests)
Test 5 $60

AT deficiency represents one of the rarest but most severe forms of inherited risk factors for thrombosis with the estimated prevalence of heterozygous AT deficiency ranging between 0.2 – 0.17% in the general population and between 0.5 – 5% in patients with VTE. It is inherited in a autosomal-dominant manner and is associated with a 5-50fold increased risk of VTE.
Please note on request if patient is on any anticoagulant. Antithrombin levels may be reduced in the neonatal period, pregnancy, liver disease, nephrotic syndrome, sepsis/DIC, and in the acute post-thrombotic phase. Heparin and estrogens may also cause aquired AT deficiency. Low levels should be CONFIRMED at a later date. The test ideally should be performed when the patient is not on warfarin treatment, as plasma levels may be elevated into the normal range. Confirmation of the hereditary nature of AT deficiency requires the investigation of other family members (autosomal dominant inheritance)

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