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antithrombin 3 in plasma (antithrombin 3 assay)

Reference range: - adults: 19-30 mg/dL (antigenic assay) - 80-120% (functional assay) Clinical significance: - used to evaluate hypercoagulable states - used to identify cause of heparin resistance - deficiency in antithrombin-3 increases the tendency towards coagulation (hypercoagulable state) Increases: 1) inflammation 2) menstruation 3) renal transplantation 4) acute hepatitis 5) obstructive jaundice 6) vitamin K deficiency 5) pharmaceutical agents a) anabolic steroids, androgens b) oral contraceptives containing progesterone c) warfarin d) gemfibrozil Decreases: 1) hereditary familial antithrombin-3 deficiency 2) disseminated intravascular coagulation (DIC) 3) hypercoagulable states (deep vein thrombosis) 4) hepatic cirrhosis 5) nephrotic syndrome 6) protein-losing enteropathy - protein wasting of malignancy 7) liver transplantation 8) partial hepatectomy 9) pharmaceutical agents a) fibrinolytics b) heparin c) L-asparaginase d) oral contraceptives containing estrogen Specimen: 1) plasma, sodium citrate (light blue-top). 2) minimal volume 0.5 mL. 3) antigenic assay a) do not thaw & refreeze b) patient should abstain from anabolic steroids, gemfibrozil, warfarin, heparin, asparaginase, estrogens, gestodene & oral contraceptives for 3 days prior to specimen collection c) shipping: refrigerated, frozen d) stability: e) room temp = 6 hours f) refrigerated = 3 days g) frozen = 3 weeks 4) functional assay: - shipping: frozen (do not thaw) Methods: 1) antigenic assay: fixed rate time nephelometry 2) functional assay: coagulation testing, chromogenic substrate (spectrophotometry)

Related

antithrombin-III (ATIII, heparin cofactor, SERPINC1, AT3, PRO0309)

Specific

antithrombin 3 antigen in plasma antithrombin 3 in activity

General

special chemistry test

References

  1. Mosby's Diagnostic and Laboratory Test Reference, 9th edition, Pagana DS and Pagana TJ editors, Mosby, Elsevier, St. Louis, 2009, pg 100
  2. Clinical Guide to Laboratory Tests, 3rd edition, NW Tietz ed, WB Saunders, Philadelphia, 1995
  3. Antithrombin, Enzymatic (Activity) Laboratory Test Directory ARUP: 30010
  4. Antithrombin Antigen Laboratory Test Directory ARUP: 30015
  5. Panel of 4 tests Laboratory Test Directory ARUP: 30177
  6. Mini Panel of 2 tests: Antithrombin, Enzymatic (Activity). Antithrombin Antigen Laboratory Test Directory ARUP: 30370
  7. Medical Knowledge Self Assessment Program (MKSAP) 17, 18, American College of Physicians, Philadelphia 2015, 2018.