Development and analytical performance of a new research use only (RUO) GP73 automated immunoassay

Area of Science:

• Biochemistry
• Clinical Chemistry
• Immunology

Background:

• Golgi protein 73 (GP73) is a recognized serum biomarker for evaluating chronic liver disease progression.
• Accurate quantification of GP73 is crucial for clinical assessment and research.

Purpose of the Study:

• To develop and validate a research use only (RUO) immunoassay for detecting serum GP73 concentration.
• To evaluate the performance characteristics of the GP73 immunoassay on the Alinity i system.

Main Methods:

• Development of a prototype immunoassay using specific internal antibodies for GP73 capture and detection.
• Utilization of an internal recombinant GP73 standard for assay calibration and controls.
• Performance evaluation including stability, precision, sensitivity (Limit of Quantitation), linearity, and interference studies on the Alinity i system.

Main Results:

• The RUO Alinity i GP73 immunoassay demonstrated excellent stability, with reagents stable on-board for over 30 days and calibrators stable at 2-8°C for 28 days.
• Assay precision showed total %CV ≤3% over 20 days, with a Limit of Quantitation (LoQ) of 0.20 ng/mL or lower.
• Linearity was confirmed within the range of 2.1 ng/mL - 1000.0 ng/mL, and no significant interference was observed from common endogenous substances or heterophile antibodies (HAMA/RF).

Conclusions:

• The developed RUO Alinity i GP73 immunoassay is reliable and robust for measuring serum GP73 concentrations.
• This validated assay provides a valuable tool for research into chronic liver disease assessment.
• The assay's performance characteristics support its potential for future clinical applications in liver disease monitoring.