Immunoassay methods for the measurement of natriuretic cardiac Hormones - ANP, BNP, and related peptides - in humans

Cardiac natriuretic peptides (ANP, BNP, and related peptides) have different patterns of production, secretion, and clearance rates. Consequently, the assays for these peptides may or may not provide complementary clinical information. Assays for cardiac natriuretic peptides have been utilized in clinical conditions associated with expanded fluid volume. In particular, these tests can be useful in discriminating between normal subjects and patients with heart failure, and can also be considered a prognostic indicator of long-term survival in patients with heart failure or after acute myocardial infarction. Non-competitive immunometric assays (such as two-site immunoradiometric assays [IRMA]), though more expensive, are preferable to radioimmunoassays (RIA) for routine assay of cardiac peptide hormones because they generally are more sensitive, accurate, and precise. However, there is no consensus on the best assay procedures for cardiac natriuretic peptides; to allow more routine use of tests for these hormones in all clinical laboratories it is necessary to develop a new generation of non-competitive immunometric methods which do not require radioactive labels and can be directly used in fully automated analytical systems.