Performance characteristics of the ARCHITECT Galectin-3 assay

Objectives: Galectin-3 is an emerging biomarker that is commonly increased in patients with heart failure and/or patients at risk for cardiovascular disease. We evaluated the Galectin-3 assay on the Abbott ARCHITECT i1000SR and ARCHITECT i2000SR at 2 testing sites. Design and methods: Imprecision (%CV), interference, limits of blank (LoB), detection (LoD), and quantitation (LoQ), linearity, method comparison to an ELISA method, comparisons between plasma and serum, and reference intervals were evaluated. Imprecision was performed based on two runs of duplicate testing conducted daily. Verification of LoB, LoD, and LoQ was performed according to Clinical and Laboratory Standards Institute guidelines. Linearity was evaluated by making 5 dilutions of a high patient EDTA plasma pool with a low patient pool. Reference intervals were established using EDTA plasma collected from self-reported healthy volunteers. A second lot of reagent was used at one site for method comparison and imprecision studies. Results: Total CV's were ≤6.0%. A positive interference was observed for hemolyzed samples over 2.0g/L hemolysate. The LoB ranged from 0.1 to 0.3ng/mL, the LoD from 1.4 to 2.1ng/mL and the LoQ from 3.0 to 3.3ng/mL. Linearity studies had slopes and correlation coefficients equal to 1.0. Comparison of the i1000SR and i2000SR to the ELISA method demonstrated slopes of 1.0 to 1.2 and correlation coefficients of 0.93 to 0.97. The 97.5th percentile of the reference interval was 18.7 and 17.9ng/mL for the i1000SR and i2000SR, respectively. Conclusions: The Abbott Galectin-3 assay demonstrated acceptable analytical performance on both the ARCHITECT i1000SR and ARCHITECT i2000SR. © 2012 The Canadian Society of Clinical Chemists.