Plasma brain natriuretic peptide measured by fully-automated immunoassay and by immunoradiometric assay compared

The clinical relevance of measuring plasma brain natriuretic peptide (BNP) is well-known, especially in patients with heart failure. Recently, a new m ethod for measuring BNP. called TRIAGE(R). has been developed which can be used for point-of-care testing of patients with congestive heart failure. T he aim of the present study is to compare the analytical performance of thi s fully-automated method to that of an immunoradiometric assay (IRMA). rout inely used to measure BNP. The TRIAGE(R) method is a non-competitive immuno fluorometric assay which uses two different binding phases, specific for tw o different epitopes of the BNP amino acid chain, to form a sandwich with t he specific ligand (i.e., BNP). A polyclonal antibody is included in the fl uorescent immunoassay reagents which are contained in the assay devices and a monoclonal antibody is immobilized in the detection lane of the assay de vice. The imprecision of the TRIAGE(R) method was approximately 12% for BNP concentrations in the normal range and about 18% for BNP concentrations ab ove the normal range. The mean reading time of the TRIAGE(R) method was 14. 5 +/-8.6 min. A close linear relationship was found between the BNP values measured with the two methods (TRIAGE=24.6+0.933 IRMA; r=0.932, n=83). The TRIAGE(R) method is indicated for BNP assay in ambulatory and coronary or e mergency units, where usually only a few samples (preferentially whole bloo d samples) must be measured in a short time. The IRMA method should be pref erred for pathophysiological studies, requiring the highest degree of preci sion and sensitivity for simultaneous measurement of several stored plasma samples or tissue extracts.