Test ID: BNP
B-Type Natriuretic Peptide (BNP), Plasma
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Aids in the diagnosis of congestive heart failure (CHF)
The role of brain natriuretic peptide in monitoring CHF therapy is under investigation
Method Name A short description of the method used to perform the test
Immunoenzymatic Assay
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Brain Natriuretic Peptide
Natriuretic Peptide
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Spin down, remove plasma from cells, and immediately freeze.
Additional Information: Include patient's age and sex.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Plasma EDTA | Frozen | 365 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
B-type natriuretic peptide (brain natriuretic peptide; BNP) is a 32-amino acid-ringed peptide secreted by the heart to regulate blood pressure and fluid balance.(1) BNP is stored in and secreted predominantly from membrane granules in the heart ventricles, and is continuously released from the heart in response to both ventricle volume expansion and pressure overload.(2)
The natriuretic peptide system and the renin-angiotensin system counteract each other in arterial pressure regulation. When arterial pressure decreases, the kidneys release renin, which activates angiotensinogen resulting in increased peripheral resistance of the arterioles, thus increasing arterial pressure.
The natriuretic peptides counteract the effects of renin secretion, causing a reduction of blood pressure and in extracellular fluid volume.(3) Both BNP and atrial natriuretic peptide (ANP) are activated by atrial and ventricular distension due to increased intracardiac pressure. These peptides have both natriuretic and diuretic properties: they raise sodium and water excretion by increasing the glomerular filtration rate and inhibiting sodium reabsorption by the kidney.
The New York Heart Association (NYHA) developed a functional classification system for congestive heart failure (CHF) consisting of 4 stages based on the severity of the symptoms. Various studies have demonstrated that circulating BNP concentrations increase with the severity of CHF based on the NYHA classification.(4-6)
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Males
< or =45 years: < or =35 pg/mL
46 years: < or =36 pg/mL
47 years: < or =37 pg/mL
48 years: < or =38 pg/mL
49 years: < or =39 pg/mL
50 years: < or =40 pg/mL
51 years: < or =41 pg/mL
52 years: < or =42 pg/mL
53 years: < or =43 pg/mL
54 years: < or =45 pg/mL
55 years: < or =46 pg/mL
56 years: < or =47 pg/mL
57 years: < or =48 pg/mL
58 years: < or =49 pg/mL
59 years: < or =51 pg/mL
60 years: < or =52 pg/mL
61 years: < or =53 pg/mL
62 years: < or =55 pg/mL
63 years: < or =56 pg/mL
64 years: < or =57 pg/mL
65 years: < or =59 pg/mL
66 years: < or =60 pg/mL
67 years: < or =62 pg/mL
68 years: < or =64 pg/mL
69 years: < or =65 pg/mL
70 years: < or =67 pg/mL
71 years: < or =69 pg/mL
72 years: < or =70 pg/mL
73 years: < or =72 pg/mL
74 years: < or =74 pg/mL
75 years: < or =76 pg/mL
76 years: < or =78 pg/mL
77 years: < or =80 pg/mL
78 years: < or =82 pg/mL
79 years: < or =84 pg/mL
80 years: < or =86 pg/mL
81 years: < or =88 pg/mL
82 years: < or =91 pg/mL
> or =83 years: < or =93 pg/mL
Females
< or =45 years: < or =64 pg/mL
46 years: < or =66 pg/mL
47 years: < or =67 pg/mL
48 years: < or =69 pg/mL
49 years: < or =71 pg/mL
50 years: < or =73 pg/mL
51 years: < or =74 pg/mL
52 years: < or =76 pg/mL
53 years: < or =78 pg/mL
54 years: < or =80 pg/mL
55 years: < or =82 pg/mL
56 years: < or =84 pg/mL
57 years: < or =87 pg/mL
58 years: < or =89 pg/mL
59 years: < or =91 pg/mL
60 years: < or =93 pg/mL
61 years: < or =96 pg/mL
62 years: < or =98 pg/mL
63 years: < or =101 pg/mL
64 years: < or =103 pg/mL
65 years: < or =106 pg/mL
66 years: < or =109 pg/mL
67 years: < or =112 pg/mL
68 years: < or =114 pg/mL
69 years: < or =117 pg/mL
70 years: < or =120 pg/mL
71 years: < or =123 pg/mL
72 years: < or =127 pg/mL
73 years: < or =130 pg/mL
74 years: < or =133 pg/mL
75 years: < or =137 pg/mL
76 years: < or =140 pg/mL
77 years: < or =144 pg/mL
78 years: < or =147 pg/mL
79 years: < or =151 pg/mL
80 years: < or =155 pg/mL
81 years: < or =159 pg/mL
82 years: < or =163 pg/mL
> or =83 years: < or =167 pg/mL
Interpretation Provides information to assist in interpretation of the test results
>normal <200 pg/mL: likely compensated congestive heart failure (CHF)
> or =200 to < or =400 pg/mL: likely moderate CHF
>400 pg/mL: likely moderate-to-severe CHF
Brain natriuretic peptide (BNP) levels are loosely correlated with New York Heart Association (NYHA) functional class (see Table).
| Interpretive Levels for CHF | ||
| Functional Class | 5th to 95th Percentile | Median |
| I | 15 to 499 pg/mL | 95 pg/mL |
| II | 10 to 1,080 pg/mL | 222 pg/mL |
| III | 38 to >1,300 pg/mL | 459 pg/mL |
| IV | 147 to >1,300 pg/mL | 1,006 pg/mL |
| All CHF | 22 to >1,300 pg/mL | 360 pg/mL |
Elevation in BNP can occur due to right heart failure with cor pulmonale (200-500 pg/mL), pulmonary hypertension (300-500 pg/mL), and acute pulmonary embolism (150-500 pg/mL). Elevations also occur in patients with acute coronary syndromes.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Lack of elevations have been reported if congestive heart failure is very acute (first hour) or with ventricular inflow obstruction (hypertrophic obstructive cardiomyopathy, mitral stenosis, atrial myxoma).
Some patients who have been exposed to animal antigens, either in the environment or as part of treatment or imaging procedures, may have circulating antianimal antibodies present. These antibodies may interfere with the assay reagents to produce unreliable results.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Krishnaswamy P, Lubien E, Clopton P, et al: Utility of B-natriuretic peptide as a rapid, point-of-care test for screening patients undergoing echocardiography to determine left ventricular dysfunction. Am J Med 2001;111(4):274-279
2. McNairy M, Gardetto N, Clopton P, et al: Stability of B-type natriuretic peptide levels during exercise in patients with congestive heart failure: implications for outpatient monitoring with B-type natriuretic peptide. Am Heart J 2002 March;143(3):406-411
3. Redfield MM, Rodeheffer RJ, Mahoney DW, et al: What is a normal BNP? - a community-based study employing two assays for measurement of BNP. J Card Fail 2001 September;7(3):30
Method Description Describes how the test is performed and provides a method-specific reference
The instrument used is a Beckman Coulter DXI 800. The brain natriuretic peptide (BNP) test is a 2-site immunoenzymatic sandwich assay. A sample is added to a reaction vessel with mouse monoclonal antihuman BNP antibody-alkaline phosphatase-conjugate and paramagnetic particles coated with mouse monoclonal antihuman BNP antibody. BNP in human plasma binds to the immobilized anti-BNP on the solid phase, while the mouse anti-BNP conjugate reacts specifically with bound BNP. After incubation in a reaction vessel, separation in a magnetic field and washing remove materials not bound to the solid phase. The chemiluminescent substrate Lumi-Phos 530 is added to the reaction vessel and light generated by the reaction is measured. The light production is directly proportional to the concentration of BNP in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve. (Package insert: Biosite Incorporated, France, 2003)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Wednesday, Friday, Sunday; 6 a.m.-3 p.m
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83880
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| BNP | B-Type Natriuretic Peptide (BNP) | 30934-4 |
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