An ELISA method detecting the active form of suPAR

Area of Science:

• Biochemistry
• Immunology
• Clinical Chemistry

Background:

• Urokinase plasminogen activator receptor (uPAR) circulates in plasma in various forms, including soluble uPAR (suPAR) and fragments.
• Distinguishing between active and inactive forms of suPAR is crucial for understanding its biological roles.

Purpose of the Study:

• To develop and validate an Enzyme-Linked Immunosorbent Assay (ELISA) for specifically detecting the active form of suPAR that binds to its ligand, urokinase plasminogen activator (uPA).
• To assess the clinical feasibility of measuring active suPAR in human plasma, particularly in pregnant women.

Main Methods:

• Development of a novel ELISA assay targeting the active conformation of suPAR.
• Validation of the assay's precision (intra-assay CV 8.5%, inter-assay CV 9.6%), recovery (99.74%), sensitivity (15 pg/ml), and linear range (0.031-8 ng/ml).
• Measurement of active suPAR levels in plasma samples from pregnant women and healthy donors.

Main Results:

• The developed ELISA assay demonstrated high accuracy, sensitivity, and a wide linear measurement range for active suPAR.
• Plasma from pregnant women showed a higher average concentration of active suPAR (1.39 ng/ml) compared to healthy donors (0.96 ng/ml).

Conclusions:

• The study successfully established a reliable method for quantifying the active form of suPAR in human plasma.
• The findings suggest that active suPAR levels may differ between physiological states, highlighting its potential as a biomarker in clinical diagnostics.