Laboratory Medicine
Test Directory / NT-Pro BNP
NT-Pro BNP
Brown clotted serum, gel barrier
| Test | NT-Pro BNP |
|---|---|
| Common Abbreviations | BNP |
| Profile | NA |
| Tube type | Brown clotted serum, gel barrier |
| Clinical Indication | Determination of NT-proBNP levels in plasma can be useful in identifying patients with heart failure, assessing the severity, predicting increased morbidity and monitoring the therapeutic response. ProBNP, the amino acid precursor of BNP, is synthesised and released by ventricular myocytes in response to increased ventricular wall tension. ProBNP is cleaved to release the active hormone (BNP) and the N-terminal inactive peptide (NT-proBNP). BNP antagonizes the renin-angiotensin-aldosterone (RAAS) system by causing natriuresis, diuresis and vasodilation-inhibiting renin excretion and aldosterone production. Plasma levels of both BNP and NT-proBNP are markedly increased in subjects with left ventricular dysfunction. NT-proBNP has shown advantages over BNP as a biochemical marker because of its longer half-life, better in vitro stability, reduced intra-individual fluctuation and higher circulating concentration. BNP levels are also raised in conditions other than heart failure including critical illness, anaemia, stroke and pulmonary disease. |
| Specimen Type | Blood |
| Sample type | Plasma |
| Minimum Volume | 0.5mL If requesting more than 10 tests please send an additional brown clotted serum sample. |
| Special Precautions | No special requirements |
| Stability | 3 days at 20-250C, 6 days at 2-80C and 2 years at -200C |
| Turnaround Time | Inpatient: 24 hours Outpatient/ GP: 24 hours |
| Laboratory | York and Scarborough |
| Reference Interval | <400 ng/L: Normal level - Heart failure unlikely 400 - 2000 ng/L: Raised level - Refer within 6 weeks if clinically appropriate >2000 ng/L: Very high level - Refer urgently if clinically appropriate Taken from NICE Clinical Guidance 108 |
| Limitations | Analysis should not be performed on haemolysed, icteric or lipaemic samples. The assay is unaffected by biotin < 123 nmol/L or < 30 ng/mL. No interference was observed from rheumatoid factors up to a concentration of 1500 IU/mL. No interference was observed from IgG < 6.0 g/dL; IgA < 1.6 g/dL; IgM < 1.0 g/dL Samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration. In vitro tests were performed on 16 commonly used pharmaceuticals. No interference with the assay was found. In addition, special cardiac drugs were tested. No interference with the assay was found. In rare cases, interference due to extremely high titers of antibodies to analyte specific antibodies, streptavidin or ruthenium can occur. |
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