Antithrombin III and plasminogen: a comparison of two synthetic substrate-based methods

Area of Science:

• Clinical Chemistry
• Biochemistry
• Hematology

Background:

• Accurate quantitation of plasma proteins like plasminogen (PLG) and antithrombin III (AT III) is crucial for diagnosing and managing various hemostatic and thrombotic disorders.
• Synthetic substrate-based assays offer a chromogenic method for measuring these critical coagulation factors.

Purpose of the Study:

• To evaluate and compare the precision and correlation of two synthetic substrate-based methods: the DuPont aca and KABI/CentrifiChem, for quantifying plasma PLG and AT III.
• To establish reference ranges for PLG and AT III in different populations.

Main Methods:

• The study utilized normal human pooled plasma (NHP) to assess method precision (within-day and day-to-day variability) for both PLG and AT III assays.
• Correlation analysis was performed by comparing results obtained from the DuPont aca and KABI/CentrifiChem methods.
• Reference ranges were determined for healthy adults, pregnant women, and cord blood specimens.

Main Results:

• Both methods demonstrated good precision for PLG quantitation, with coefficients of variation (CVs) generally below 5%.
• The correlation between the two methods for PLG was strong (r = 0.979).
• AT III assays also showed acceptable precision (CVs < 7.0%), with a strong correlation between the methods (r = 0.952).

Conclusions:

• The DuPont aca and KABI/CentrifiChem methods provide reliable and comparable results for the quantitation of plasma PLG and AT III.
• These synthetic substrate-based assays are suitable for routine clinical laboratory use.
• The study presents valuable reference ranges for these proteins in diverse populations.