Determination of B-Type Natriuretic Peptides: Clinical And Analytical Quality

Determination of B-Type Natriuretic Peptides: Clinical And Analytical Quality B-type natriuretic peptide (BNP), a neurohormone synthesized in the cardiac ventricles, is released as preproBNP and then enzymatically cleaved to the N-terminal-proBNP (NT-proBNP) and BNP upon ventricular myocite stretch. This hormone has a role in the body's defense against hypertension and plasma volume expansion. Measurements of circulating B-type natriuretic peptides have been shown to be of diagnostic value in patients with heart failure. BNP levels correlate with the severity of heart failure, as well as with prognosis. Better control of the preanalytical and analytical sources of variations will undoubtedly lead to improvement in B-type natriuretic peptides measurements. A number of preanalytical and analytical factors including specimen type and stability, assay imprecision, and standardization are reviewed here. Further research is required to better define the performance characteristics necessary for assays bearing the designation natriuretic peptides. These characteristics include developing guidelines for the total analytical error from a careful review of the intraindividual biological variability of the analyte under conditions that will be encountered in clinical practice, then validating these guidelines in the clinical setting, and completing the standardization efforts.