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 BNP-32 assay kit crossreacts proBNP-108. We investigated why proBNP is increased without processing in HF.
Design, setting, and patients: We measured plasma BNP-32 and proBNP-108 in normal subjects (n=10) and patients with atrial fibrillation (AF) (n=18) and HF (n=132). We also measured BNP-32 and proBNP-108 in ventricular and atrial tissue and in pericardial fluid by specific fluorescent enzyme immunoassay following Sep-Pak C18 cartridge extraction and gel-filtration.
Main outcome measures: Both BNP-32 and proBNP-108 were higher in HF than in control or AF (both P<0.01), and there was a significant correlation between the levels of these peptides (r=0.94, P<0.001). The proBNP-108/total BNP (BNP-32+proBNP-108) ratio was widely distributed and lower in HF (0.33±0.17) than in control (0.41±0.06, P<0.05) and AF (0.45±0.04: P<0.002). HF with ventricular overload had higher proBNP-108/ total BNP ratio (45±10%) than HF with atrial overload (20±11%, P<0.001). Consistent with this finding, proBNP-108 was the major molecular form in ventricular tissue (n=6, 67±4%), and BNP-32 was the major molecular form in atrial tissue (n=7, 76±5%, P<0.0001). In addition, proBNP-108 was the major molecular form of BNP in pericardial fluid (n=8, 82±5%). The proBNP-108/total BNP ratio increased with deterioration of HF and decreased with improvement of HF.
Conclusion: These results suggest that not only BNP-32, but also proBNP-108 is increased in HF and that proBNP/total BNP ratio increases in association with pathophysiological conditions such as ventricular overload.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.