A method for the differential determination of plasma antithrombins

Area of Science:

• Biochemistry
• Hematology

Background:

• Plasma contains multiple antithrombin proteins, including antithrombin III and alpha2 macroglobulin, which play crucial roles in regulating coagulation.
• Accurate measurement of individual antithrombin levels is essential for understanding hemostasis and diagnosing related disorders.

Purpose of the Study:

• To develop and validate a method for the differential determination of plasma antithrombin III and alpha2 macroglobulin.
• To assess the relative contribution of antithrombin III to total antithrombin activity in healthy subjects and patients with liver cirrhosis.

Main Methods:

• Selective inactivation of alpha2 macroglobulin using methylamine treatment.
• Quantification of thrombin inhibition by antithrombin III and alpha2 macroglobulin in defibrinated plasma.
• Pseudo-first order reaction kinetics were utilized for analysis.

Main Results:

• Antithrombin III constitutes approximately 70% of total antithrombin activity in healthy individuals.
• Patients with liver cirrhosis exhibit reduced total antithrombin activity.
• The relative contribution of antithrombin III is significantly lower in liver cirrhosis patients compared to healthy subjects.

Conclusions:

• The described method allows for the selective measurement of antithrombin III and alpha2 macroglobulin.
• Antithrombin III is the predominant antithrombin in healthy plasma.
• Altered antithrombin profiles, particularly a reduced role of antithrombin III, are observed in liver cirrhosis.