Finding a reliable assay for soluble neprilysin.

Area of Science:

• Biomarker discovery and validation
• Assay development and standardization
• Proteomics and immunoassay technology

Background:

• Research-use-only (RUO) immunoassays lack standardization, impacting data authenticity and reproducibility.
• Commercial neprilysin immunoassays show poor inter-assay correlation, necessitating validation.
• Ensuring reliable neprilysin measurements is vital for scientific rigor in biomarker research.

Purpose of the Study:

• To identify and validate dependable commercial immunoassays for measuring soluble neprilysin (sNEP).
• To enhance the scientific rigor and reproducibility of neprilysin-related investigations.
• To improve the overall quality of biomarker research through assay standardization.

Main Methods:

• Analyzed soluble neprilysin (sNEP) concentrations in 532 participants across three international cohorts using six commercial immunoassay kits.
• Correlated sNEP concentrations between different assays and with plasma neprilysin activity.
• Validated assay reliability through performance verification, mass spectrometry (MS) analysis, and cross-reactivity testing.

Main Results:

• Only the Aviscera Bioscience sNEP ELISA SK00724-01 showed significant inter-laboratory correlation in Spain and New Zealand cohorts.
• Perkin Elmer AlphaLISA and Biotechne ELLA assays in the Singapore cohort exhibited strong agreement (r=0.89) and correlated well with neprilysin activity (r=0.87, 0.77).
• MS analysis confirmed authentic neprilysin, and the AlphaLISA assay met performance criteria with no significant cross-reactivity.

Conclusions:

• The AlphaLISA and ELLA assay platforms provide reliable quantification of soluble neprilysin (sNEP) concentrations.
• The reliability of other commercial neprilysin immunoassays requires further investigation.
• Validated assays are essential for accurate neprilysin biomarker research.