Evaluation of fundamental performance of HISCL-5000^®, an automatic immunoassay instrument for the measurement of serum NT-proBNP

Abstract

N-terminal pro B-type natriuretic peptide (NT-proBNP) is a useful biomarker for the diagnosis and/or management of chronic heart failure. Here, we show the results of the evaluation of a new instrument for serum NT-proBNP assay, HISCL-5000^® (Sysmex). We performed fundamental evaluations of the NT-proBNP assay using HISCL-5000^®, namely, intra- and inter-assay variances, linearity for serially diluted samples and effects of several substances. The coefficients of variance (CVs) for intra- and inter- assays using control samples were between 0.9 and 2.4%. In a linear regression analysis of the serially diluted samples, we obtained a constant linearity between 0 and 34,434 pg/mL (r² ‍= ‍0.997, p < 0.001). There is no significant interference (less than 10%) by the existing direct bilirubin, conjugated bilirubin, hemoglobin, chylous fluids, and rheumatoid factor on the measurements of NT-proBNP. Furthermore, we evaluated the consistency of this assay with another electro-chemiluminescence immunoassay for NT-proBNP (EClusys^®analyzer, Roche Diagnostics KK, Tokyo, Japan) using 112 serum samples. Although the absolute values obtained by HISCL-5000^® measurements tend to be lower than those obtained by ECLusys^® measurements (linear regression equation: y = 0.85x + 183.2), they were considered consistent with each other (correlation coefficient of 0.99). These results indicate that HISCL-5000^® can be applied to serum NT-proBNP measurements for routine use in the laboratory.