A-019 Clinical Laboratory Evaluation of the Analytical Performance of the Atellica IM NT-proBNPII (PBNPII) Assay on the Atellica CI Analyzer

Abstract Background The Atellica IM NT-proBNPII (PBNPII) assay quantifies the amount of N-terminal pro-brain natriuretic peptide (NT-proBNP) in human serum and plasma (EDTA and lithium heparin). In the Emergency Department and Outpatient populations, measurements of NT-proBNP are used as an aid in diagnosis of heart failure (HF) in patients with clinical suspicion of new onset or worsening HF. In this study, two clinical laboratories verified the performance of the Atellica IM PBNPII assay on the Atellica CI analyzer. Methods The Atellica IM PBNPII assay is a fully automated 2-site sandwich immunoassay using direct chemiluminescent technology, which uses constant amounts of 2 monoclonal antibodies. Studies were conducted separately, at two clinical laboratories. Linearity verification studies tested N equal to or greater than 5 levels of mixed high and low samples (N=3/level) over 1 day per CLSI EP06-ed2. Verification of precision was determined per CLSI EP15-A3 using 1 serum pool and 2 levels of Bio-Rad quality control material. Repeatability and within-lab precision samples were tested running 5 replicates of each level each day for 5 days (N=25/level). Method comparison studies compared assay performance of the PBNPII assay on the Atellica CI analyzer to either the VITROS 5600 NT-PBNP (N=24) or Dimension EXL LNTP (N=39) using single replicates of native human serum per CLSI EP09c-ed3. Results Linear range was verified across the measuring range, 35-35,000 pg/mL. Coefficients of variation (CV) for each site’s repeatability were 1.3-2.9% and within lab, 2.6-3.4% at 135.5-4416.0 pg/mL. Comparison of NT-proBNP as measured using the (1) VITROS 5600 and (2) Dimension EXL to the Atellica CI was analyzed using Weighted-Deming regression analysis, yielded: (1) y=0.99x + 3.72 pg/mL at 40.0 to 28,814 pg/mL (NTBNP vs PBNPII) with r=0.995 and (2) yielded y=0.99x + 4.21 pg/mL at 39.0 to 34,700 pg/mL (LNTP vs PBNPII) with r=0.999, respectively. Conclusion The Atellica IM PBNPII assay on the Atellica CI Analyzer demonstrated acceptable analytical performance at both laboratory sites. Method comparison studies show results correlate well between two established assays and the Atellica IM PBNPII assay on the Atellica CI.