Diversity of Molecular Forms of Plasma Brain Natriuretic Peptide in Heart failure –Different proBNP-108 to BNP-32 Ratios in Atrial and Ventricular Overload–

Objective Recent studies have shown that plasma levels of brain natriuretic peptide (BNP)-32 and proBNP-108 are increased in heart failure (HF) and that the BNP-32 assay kit in current clinical use cross-reacts with proBNP-108. We investigated why proBNP is increased without processing in HF was investigated. Design, setting and patients Plasma BNP-32 and proBNP-108 in normal individuals (n=10) and in patients with atrial fibrillation (AF) (n=18) and HF (n=132) was measured. BNP-32 and proBNP-108 in ventricular and atrial tissue and in pericardial fluid using a specific fluorescent enzyme immunoassay following Sep-Pak C18 (Waters, Milford, Massachusetts, USA) cartridge extraction and gel filtration was also measured. Main outcome measures Levels of both BNP-32 and proBNP-108 were higher in HF than in control or AF (both p Conclusion These results suggest that BNP-32 and proBNP-108 is increased in HF and that the proBNP/total BNP ratio increases in association with pathophysiological conditions such as ventricular overload.