Assay overview
When it comes to laboratory antithrombin tests, NODIA has it all. Find out more about our tests on this antithrombin specific page.
General information
Classification of Antithrombin deficiencies
Congenital Antithrombin deficiencies can be classed in 4 different groups:
- Type I: Decreased Antithrombin antigen concentration and decreased Antithrombin activity.
- Type II: Decreased Antithrombin activity but normal antithrombin antigen.
- Type II Subtypes:
- RS (Reactive Site): Normal Antithrombin antigen concentration and decreased biological activity; a protein abnormality is present at the active site.
- Type II HBS (Heparin Binding Site): Normal Antithrombin antigen concentration, normal Antithrombin activity in the absence of heparin, but decreased in its presence. An abnormality lies in the Heparin-AT bond. Can be detected with progressive AT activity assays.
- Type II (Pleiotropic): Decreased Antithrombin activity in combination with a lowered antigen level.
Functional assay of AT associated with an immunoassay allows to characterize the deficiency type
Biochemistry
Antithrombin is a single chain glycoprotein synthesized in the liver and has a molecular weight of about 58.200 daltons. Its concentration in normal plasma is about 125µg/ml. The half life is 2-3 days.
AT is a direct inhibitor of thrombin (factor IIa) and Factor Xa, but also of other serine proteases, such as factor IXa, XIa and XIIa, plasmin and kallikrein.
Heparin accelerates dramatically the inhibition of Thrombin and Factor Xa. The Antithrombin concentration, like Protein C and Protein S concentrations, plays an important role in the hemostatic balance
- Anti Xa Chromogenic assay for measuring Antithrombin -
Introduction
BIOPHENTM AT anti-(h)-Xa LRT kit is a chromogenic one stage assay for the in vitro quantitative determination of Antithrombin (AT) activity on human citrated plasma using an anti-Xa method, manual or automated.
Reagents are in the liquid presentation, ready to use.
NODIA's choice
Recommended product for all your routine lab anti-Xa testing
Reaction principle
Intended use
Diagnosis of congenital or acquired Antithrombin deficiencies.
Major Features
- Ready-to-use liquid reagent technology
- All Human Factors
- High on board stability
- Insensitive for heparin
- Automation protocols available
Tip
Avoid DOAC interference through the use of DOAC-Remove or DP-Filter
- Anti Xa Chromogenic assay for measuring Antithrombin -
Introduction
BIOPHENTM AT (LRT) kit is a chromogenic one stage assay for the quantitative determination of the heparin cofactor activity of Antithrombin (AT) in human citrated plasma using an anti Xa method, manual or automated. This method uses Bovine reagents that are liquid and for this ready to use.
NODIA's choice
Recommended product for STA-R users for routine lab anti-Xa testing
Reaction principle
Intended use
Diagnosis of congenital or acquired Antithrombin deficiencies.
Major Features
- Ready-to-use liquid reagent technology
- High on board stability
- Insensitive for heparin
- Automation protocols available
TIP
The BIOPHENTM AT (LRT) assay is a kinetic one stage assay based on the inhibition of Factor Xa, which is at a constant concentration and in excess, by Antithrombin in presence of heparin. The remaining Factor Xa is then measured by its amydolitic activity on a Factor Xa specific chromogenic substrate, which releases pNA. The amount of pNA generated is inversely proportional to the Antithrombin concentration present in the tested plasma.
Due to the assay’s insensitivity to heparin, plasmas from patients on heparin therapy may be tested.
- 2 Stage Heparin Anti-IIa Chromogenic assay for measuring antithrombin -
Introduction
Antithrombin (AT) is the major physiological coagulation inhibitor. When complexed to heparin, AT becomes a potent and fast acting inhibitor of different coagulation serine esterases. This anti-IIa assay thus measures the heparin dependent anti-IIa activity of AT.
Reaction Principle
The BIOPHEN™ AT (Anti-IIa) method is an two stage assay based on the inhibition of a constant and in excess amount of Thrombin (IIa), by the tested AT in presence of an excess of heparin, and hydrolysis of a Thrombin specific chromogenic substrate, by Thrombin in excess. pNA is then released from the substrate. The amount of pNA released (measured by absorbance at 405nm) is then representative for the residual Thrombin quantity. There is an inverse relationship to the concentration of AT present in the tested sample.
Variant Method: Progressive Antithrombin Activity
For the identification of type II abnormality, Heparin Binding Site (HBS), a variant method can be performed using a specific “Tris buffer without heparin” (AR104A) instead of “R3 buffer”.
A specific calibration curve must be done with BIOPHEN™ Plasma Calibrator and the patient AT activity (HBS) is directly read on the curve. The specific protocol is available upon request. In presence of the HBS variant, the patient has a normal AT activity with this method.
- 2 Stage Heparin Anti-Xa Chromogenic assay for measuring antithrombin -
Introduction
Reaction principle
The BIOPHEN™ Antithrombin method is a kinetic two stage assay with it’s main principle based on the inhibition of FXa, which is at a constant concentration and in excess, by AT in presence of heparin. The remaining FXa is then measured by its amydolitic activity on a FXa specific chromogenic substrate, which releases pNA. The amount of pNA generated is inversely proportional to the AT concentration present in the tested plasma.
Due to the assay’s insensitivity to heparin, plasma from patients on heparin therapy may be tested.
Variant Method: Progressive Antithrombin Activity
For the identification of type II abnormality, HBS (Heparin Binding Site), a variant method can be used. The Bovine FXa vial must be restored with 2.5 mL of Tris buffer (AR103), without heparin.
A calibration curve must be done with the BIOPHEN™ Plasma Calibrator and the patient AT activity (HBS) is directly read on the curve. The specific protocol is available upon request.
In presence of the HBS variant, the patient has a normal AT activity with this
method.
Reaction principle
Major features
- Adaptations to the various automates are available
- High on board stability
- No hook effect is observed for AT concentrations below 200%
FYI: The AT antigen concentration measured in serum is 20 to 30% lower compared to plasma. The AT concentration measured in serum with the Liaphen AT is higher than the AT concentration measured with a functional assays due to AT consumption during clotting, whilst it will be identical to the concentration found in plasma.
An antithrombin concentration ≤ 70% indicates the presence of a quantitative deficiency, which must be confirmed by another test and/or by testing another plasma sample from the patient.
DIY
Antibodies for immunoblotting, immunostaining of cells and several types of immunoassays where a higher signal-to-noise is required:
Human Antithrombin Neutralization, Mached Pair Antibodies can be used to inactivate (neutralize) the ability of ATIII to inhibit thrombin or activated factor X, even in the presence of heparin.
Antithrombin Deficient plasma
Both Lyophilized and Frozen Human Antithrombin Deficient Plasmas are available for any in vitro protocol or research study where a source of human ATIII deficient plasma is required.
In case the Antithrombin-Heparin Cofactor II complex is of interested we suggest the Human Antithrombin Heparin Cofactor II Deficient Plasmas.
FYI
By definition, a 100% AT concentration corresponds to the concentration in a normal human citrated plasma pool, obtained by pooling plasmas from healthy males or females aged from 18 to 55 years, and out of any medication. The level of AT in healthy adults is usually comprised between 80 and 120%.
Product overview
| Reference | Product name | Packaging | Categories | Manufacturer |
|---|---|---|---|---|
| 221111 | BIOPHEN™ Antithrombin LRT | 4 x 70 tests | Chromogenic Assays | HYPHEN BioMed |
| 221123 | BIOPHEN™ Antithrombin Anti-(h)-Xa LRT – small | 3 x 3ml | Chromogenic Assays | HYPHEN BioMed |
| 221127 | BIOPHEN™ Antithrombin Anti-(h)-Xa LRT – large | 4 x 7.5ml | Chromogenic Assays | HYPHEN BioMed |
| 221122 | BIOPHEN™ Antithrombin (Anti-IIa) | 2 x 2.5ml | Chromogenic Assays | HYPHEN BioMed |
| 221102 | BIOPHEN™ Antithrombin (Anti-Xa) 2.5 | 2 x 25 tests | Chromogenic Assays | HYPHEN BioMed |
| 221105 | BIOPHEN™ Antithrombin (Anti-Xa) 5 | 4 x 50 tests | Chromogenic Assays | HYPHEN BioMed |
| 120002 | LIAPHEN™ Antithrombin (ATIII) | 2 x 40 tests | Latex Immuno Assays | HYPHEN BioMed |
| 222101 | BIOPHEN™ Plasma Calibrator | 12 x 1ml | Calibrators | HYPHEN BioMed |
| 223201 | BIOPHEN™ Normal Control Plasma | 12 x 1ml | Controls | HYPHEN BioMed |
| 223301 | BIOPHEN™ Abnormal Control Plasma | 12 x 1ml | Controls | HYPHEN BioMed |
| 5D-42104F | Human Antithrombin Deficient Plasma, Frozen | 1mL | Deficient Plasmas | 5-Diagnostics |
| 5D-42104L | Human Antithrombin Deficient Plasma, Lyophilized | 1mL | Deficient Plasmas | 5-Diagnostics |
| 5D-42246F | Human Antithrombin-Heparin Cofactor II Deficient Plasma, Frozen | 1mL | Deficient Plasmas | 5-Diagnostics |
| 5D-42246L | Human Antithrombin-Heparin Cofactor II Deficient Plasma, Lyophilized | 1mL | Deficient Plasmas | 5-Diagnostics |
| PP004A | Human Antithrombin III – small | 150µg (1PEU) | Proteins & Enzymes | HYPHEN BioMed |
| PP004K | Human Antithrombin III – small x6 | 6 x 150ug | Proteins & Enzymes | HYPHEN BioMed |
| PP004B | Human Antithrombin III – medium | 1.5mg (10PEU) | Proteins & Enzymes | HYPHEN BioMed |
| PP004L | Human Antithrombin III – medium x10 | 10 x 1.5mg (10PEU) | Proteins & Enzymes | HYPHEN BioMed |
| PP004D | Human Antithrombin III – large | 3.75mg (25PEU) | Proteins & Enzymes | HYPHEN BioMed |
| PP004M | Human Antithrombin III – large x10 | 10 x 3.75mg (25PEU) | Proteins & Enzymes | HYPHEN BioMed |
| PP004C | Human Antithrombin III – extra large | 10mg Grade 1 | Proteins & Enzymes | HYPHEN BioMed |
| AR103A | Tris Buffer Anti-Xa (progressive Antithrombin) | 10ml | Auxiliary Reagents | HYPHEN BioMed |
| AR104A | Tris Buffer Anti-IIa (Progressive Antithrombin) | 10ml | Auxiliary Reagents | HYPHEN BioMed |
| 5D-10104G | Anti-human Antithrombin III (ATIII), Goat, Purified IgG | 10mg | Antibodies | 5-Diagnostics |
| 5D-10104S | Anti-human Antithrombin III (ATIII), Sheep, Purified IgG | 10mg | Antibodies | 5-Diagnostics |
| 5D-11104G | Anti-human Antithrombin III (ATIII), Goat, Affinity Purified IgG | 0.5mg | Antibodies | 5-Diagnostics |
| 5D-11104S | Anti-human Antithrombin III (ATIII), Sheep, Affinity Purified IgG | 0.5mg | Antibodies | 5-Diagnostics |
| 5D-15104S | Anti-human Antithrombin III (ATIII), Sheep, Affinity Purified HRP Conjugated IgG | 0.1mg | Antibodies | 5-Diagnostics |
| 5D-17104S | Anti-human Antithrombin III (ATIII), Sheep, Affinity Purified Biotinylated IgG | 0.1mg | Antibodies | 5-Diagnostics |
| 5D-18104 | 5-EIA Anti-human Antithrombin, Matched Pair Antibodies | 5 plates | Antibodies | 5-Diagnostics |
| 5D-18235 | 5-EIA Anti-human Thrombin-Antithrombin Complex, Matched Pair Antibodies | 5 plates | Antibodies | 5-Diagnostics |
