Antithrombin III Activity with Reflex to Antithrombin III Antigen
Quest Diagnostics
Sample type: Plasma
Requires fasting: No
Phlebotomy required
Details
Antithrombin III Activity with Reflex to Antithrombin III Antigen - Aids in characterization of Antithrombin deficiency (AT, previously referred to as Antithrombin III) which is associated with increased thrombotic risk. Type I deficiency is characterized by reduction in activity and antigen levels simultaneously. With type II deficiency, activity levels are lower in comparison to the antigen levels (dysfunctional protein). Acquired deficiency, more common than inherited defects, can occur due to: liver disease, nephrotic syndrome, heparin therapy, disseminated intra- vascular coagulation (DIC), sepsis, and L-asparaginase chemotherapy.
Reflex testing uses predefined clinical logic to automatically order one or more follow-up tests based on the initial test results. Reflex tests are performed automatically without the intervention of the ordering practitioner. They are conducted using the same sample your Patient already provided. If reflex tests are required, there will be additional charges.
Initial test
- Antithrombin III Activity
Possible reflex biomarkers
- Antithrombin III Antigen
Estimated days for results: Results should be available within 2 - 5 business days after samples are received at the lab.
Antithrombin III Activity with Reflex to Antithrombin III Antigen - Aids in characterization of Antithrombin deficiency (AT, previously referred to as Antithrombin III) which is associated with increased thrombotic risk. Type I deficiency is characterized by reduction in activity and antigen levels simultaneously. With type II deficiency, activity levels are lower in comparison to the antigen levels (dysfunctional protein). Acquired deficiency, more common than inherited defects, can occur due to: liver disease, nephrotic syndrome, heparin therapy, disseminated intra- vascular coagulation (DIC), sepsis, and L-asparaginase chemotherapy.
Expected impact by therapeutic levels (potential interference depends upon drug concentration):
- Warfarin: no effect
- Heparin (UFH or LMWH): no effect to decrease (UFH may decrease levels physiologically but no assay interference)
- Dabigatran or Argatroban (Thrombin Inhibitors): may falsely increase activity levels
- Rivaroxaban, Apixaban, Edoxaban (Factor Xa Inhibitors): no effect
2–5 business days
31 days-2 months 50-120 % normal
3-5 months 73-120 % normal
≥6 months 80-135 % normal
Blood Draw Options with Fullscript
Fullscript offers several convenient phlebotomy options to complete your lab testing:
Quest Diagnostics Patient Service Centers (PSC)
- Location: Visit a nearby Quest Diagnostics Patient Service Center.
- Cost: $10 sample collection fee (paid during lab order checkout).
- Scheduling: Schedule your appointment here. Appointments are recommended to reduce wait times. Walk-ins are accepted, but may experience delays. Aim to arrive 10 minutes before your appointment.
- Collection Instructions:
- Bring a valid ID.
- Bring your digital or printed requisition form, available in the Labs tab of your Fullscript account.
- Check-in: Scan the QR code from your confirmation email or follow kiosk instructions.
- More Info: Quest Diagnostics blood draw guide
Getlabs Mobile Phlebotomy
- Location: Sample collection at your home or office.
- Cost: $85 sample collection fee (paid during lab order checkout).
- Availability: Available in most locations – enter your ZIP code during checkout to confirm.
- Scheduling: Schedule your appointment here through your Fullscript account.
- Collection Instructions:
- Have your digital or printed requisition form and valid ID ready.
- Your phlebotomist will contact you by phone to coordinate arrival.
- More Info: Getlabs blood draw guide
- Preferred Specimen(s): 1 mL frozen platelet-poor plasma collected in each of two 3.2% sodium citrate (light blue-top) tubes
- Alternative: NA
- Minimum Volume: NA
- Collection Instructions: NA
- Transport Container: Transport tube
- Transport Temperature: Frozen
- Specimen Stability:
- Frozen: 30 days
- Reject Criteria:
- Gross hemolysis • Grossly lipemic • Grossly icteric
State restrictions:
Patient can't order this test if they are located in Puerto Rico, Hawaii, Rhode Island, New Jersey, or New York
