Chemistry
Cardiac related
Natriuretic peptides (BNP and Amino-terminal proBNP)

Author: Larry Bernstein, M.D. (see Authors page)

Revised: 2 February 2016, last major update December 2010

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Natriuretic peptides [title]
Cite this page: Natriuretic peptides (BNP and Amino-terminal proBNP). PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/chemistrycardiacnatriuretic.html. Accessed December 9th, 2016.
Definition / General
  • Brain natriuretic peptide (BNP), now known as B-type natriuretic peptide (also BNP), is a 32 amino acid polypeptide secreted by the cardiac ventricles in response to excessive stretching of cardiomyocytes (Wikipedia - Brain natriuretic peptide)
  • BNP was originally identified in extracts of porcine brain, although in humans it is produced mainly in the cardiac ventricles
  • BNP is co-secreted with a 76 amino acid N-terminal fragment (NT-proBNP), which is biologically inactive
Clinical Features
  • Reduces misdiagnosis of congestive heart failure, which occurs 50% to 75% of the time
  • NT-proBNP is superior to BNP for predicting mortality and morbidity for heart failure (Clin Chem 2006;52:1528), and coexisting renal disease and heart failure (Clin Chem 2007;53:1511)
Laboratory
Indications

Reference ranges
  • BNP levels below 100 pg/mL indicate no heart failure

Limitations
  • Determination of endogenous BNP with the AxSYM assay using frozen plasma samples may not be valid after 1 day, but NT-proBNP as measured by the Elecsys assay may be stored at -20 degrees C for at least four months without a relevant loss of the immunoreactive analyte (Clin Chem Lab Med 2004;42:942)