A-020 Apolipoprotein B (ApoB) measurement by Nuclear Magnetic Resonance (NMR) Spectroscopy is Comparable to Clinical Immunoassay

Abstract

Comprehensive lipoprotein analysis and interpretation is a cornerstone of cardiovascular disease (CVD) prevention. Often, multiple platforms and assays are used to quantify lipoprotein parameters and apolipoproteins. Growing economic pressure in healthcare systems is driving the need for efficient technologies capable of measuring multiple analytes in a single analytical step. Nuclear magnetic resonance (NMR) enables simultaneous quantification of lipoprotein subclasses and related biomarkers in one integrated measurement. Although apolipoprotein B (ApoB) has previously been described as an NMR-derived parameter, its implementation has been limited to research-use-only (RUO) applications, restricting routine clinical adoption. Herein, we present the IVD-grade analytical validation of an AXINON® NMR-based ApoB, benchmarked independently against two routine clinical chemistry analyzers, aiming to enable?future?integration into clinical routine diagnostics. NMR analytical experiments for precision, linearity, and method comparison were performed using the AXINON® ApoB research use only modules (numares AG, Regensburg, Germany) at two different sites. Method comparison was performed against two different commercially available clinical analyzers (Thermofisher Optilite and Roche Cobas c501). Samples were derived from clinical residual serum collected in plain serum clot tubes (RED: n=241) or serum separator tubes (SST: n=66). Within-laboratory coefficients of variation (CVWL) and repeatability (CVr) were determined by replicate measures (n=14) on different runs. Linearity was assessed by mixing samples (n=14) with a high and low ApoB concentration at various concentrations. Imprecision was determined at various concentrations of ApoB (range 35.5 – 145.5 mg/dL); CVWL was <3.8% and CVr was <2.9%, for all sites and concentrations. The linear slope was between 0.97 and 1.01, bias was <4.5mg/dL and correlation was >0.99 for both sites. The mean absolute error (MAE) was 7 mg/dL compared to Roche and 5.5 mg/dL for Optilite measured ApoB. The percentage of measurements within 15% of Roche ApoB was > 83% Red and >86% for SST: all samples (n=34) were within 15% of Optilite ApoB. Our data support that AXINON® NMR-based ApoB shows comparable precision, and concordance with commercially available ApoB immunoassays. ApoB NMR profiling in addition to lipoprotein particle number and lipoprotein size may provide expanded utility for lipid management.