Antithrombin.

Area of Science:

• Biochemistry
• Hematology
• Molecular Biology

Background:

• Antithrombin (AT) is a key serine protease inhibitor and heparin cofactor, primarily synthesized in the liver.
• AT regulates coagulation by inhibiting thrombin and Factor Xa, among other proteases.
• Deficiencies in AT lead to excessive thrombin generation, increasing thrombotic risk.

Purpose of the Study:

• To review the diagnostic approaches for antithrombin deficiency.
• To highlight the utility of functional assays over genetic screening for AT deficiency.
• To differentiate between hereditary AT deficiency types.

Main Methods:

• Review of existing literature on antithrombin function and deficiency.
• Discussion of diagnostic methodologies including functional and immunological assays.
• Comparison of genetic testing versus functional/immunological assays for AT deficiency.

Main Results:

• Functional antithrombin (AT) amidolytic assays are the recommended initial diagnostic tool for AT deficiency.
• Routine genetic screening for AT mutations is not indicated due to complexity and limited therapeutic benefit.
• Immunological assays are valuable for differentiating between Type I and Type II hereditary AT deficiencies.

Conclusions:

• Functional amidolytic assays are the preferred method for diagnosing antithrombin deficiency.
• Genetic testing for AT mutations is generally not recommended for routine clinical practice.
• Distinguishing between hereditary AT deficiency types can be achieved using immunological assays.