B-type natriuretic peptide (BNP)--validation of an immediate response assay.

B-type natriuretic peptide, a proteohormone secreted by the left ventricle in response to wall-tension, is a promising laboratory parameter for the detection and follow-up of heart failure. In this report analytical validation data of a non-isotopic point-of-care testing system for the quantitative determination of BNP (Triage BNP, Biosite, USA) are given. Despite a very short turn-around time of about 10 minutes the assay proved to be reproducible (interassay coefficient of variation (n=10) of 8.4% and 8.0% at concentrations of 19.3 ng/l and 392 ng/l, respectively), linear (r=0.998, from 5 ng/l to 818 ng/l), and rugged with respect to common interferents; compared to the widely used SHIONORIA BNP assay (CIS, France) higher results were found (Triage-BNP = 1.52 x SHIONORIA BNP - 7.0 ng/l; n=70) with a relatively close correlation of the results (r=0.935). It is concluded that the Triage BNP assay meets the analytical requirements for further clinical validation and may allow a more widespread clinical use of BNP determination in contrast to competing assays with long turn-around times.