Q: One of my relatives has been asked to undergo P-BNP test. The lab charged Rs 1500/ for the same. The result is given as P-BNP(ECL) 446.7pmol/L. Can I get information about the test and the reference range for men and women? What is the significance of the figure above?

A:Brain natriuretic peptide (BNP) is a protein that is produced by the muscles of the heart (particularly left ventricle) in response to a variety of stimuli. Its level in the blood (or plasma, P-BNP) correlates with the presence and severity of heart failure. It is thus used to diagnose & assess severity of heart failure and to monitor the response to treatment. The biological reference interval varies from laboratory to laboratory but generally a value of less than 100 pg/ml is taken to be normal. Its level varies with age, sex, body mass index and genetic factors with higher levels being seen in the elderly & women. An elevated BNP in heart failure falls following treatment. You need to discuss the report with your doctor who will be best placed to advise.