Download biomedica product listNT-proCNP ELISA | BI-20812
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Category number
BI-20812
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Method
Sandwich ELISA, HRP/TMB, 12×8-well detachable strips
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Sample type
Serum, EDTA plasma, citrate plasma, heparın plasma, urine, cell culture supernatant, human and non-human samples
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Assay time
20 min / 3 h / 30 min
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Sample volume
20 µl / well
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Sensitivity
0.7 pmol/l (= 3.49 pg/ml)
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Standard range
0 – 128 pmol/l (= 0 – 638 pg/ml)
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Conversion factor
1 pmol/l = 4.985 pg/ml (MW: 4.985 kDa)
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Specificity
This assay recognizes recombinant and endogenous NT-proCNP.
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Precision
In-between-run (n=8): ≤ 7 % CV
Within-run (n=5): ≤ 6 % CV
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Validation Data
See validation data tab for: precision, accuracy, dilution linearity, values for healthy donors etc.
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Detection target
Recombinant and endogenous NT-proCNP.
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Use
Research use only
NT-proCNP ELISA Product overview
The NT-proCNP ELISA kit is a 4 hour, 96-well sandwich enzyme-linked immunosorbent assay (ELISA) for the quantitative determination of NT-proCNP in human serum, plasma, urine, cell culture supernatants and non-human samples (rat, mouse, pig).
NT-proCNP ELISA Assay Principle
The CNP ELISA is a sandwich enzyme immunoassay for the quantitative determination of NT-proCNP in human serum, plasma, urine, cell culture supernatants and non-human samples (rat, mouse, pig).
The figure below explains the principle of a sandwich ELISA:
In a first step, assay buffer and standard/control/sample are pipetted into the wells of the microtiter strips, which are pre-coated with polyclonal sheep anti-NT-proCNP antibody, for a short incubation. Without the need of a washing step, conjugate (sheep anti-human NT-proCNP-HRP) is added into the wells. NT proCNP present in the standrad/sample/control binds to the precoated antibody in the well and forms a sandwich with the detection antibody. In the washing step all non-specific unbound material is removed. After a final washing step, the substrate (TMB, tetramethylbenzidine) is pipetted into the wells. The enzyme-catalyzed color change of the substrate is directly proportional to the amount of NT pro CNP present in the sample. This color change is detectable with a standard microtiter plate ELISA reader.
The NT-proCNP ELISA kit uses highly purified, epitope-mapped antibodies. The antibodies utilized in the NT proCNP ELISA (BI-20892) are as follows:
- Capture antibody: polyclonal sheep anti-NT-proCNP (epitope: AA62-68 of Uniprot ID P23582)
- Detection antibody: polyclonal sheep anti-NT-proANP (epitope: AA34-37 of Uniprot ID P23582)
NT-proCNP ELISA Typical Standard Curve
The figure below shows a typical standard curve for the NT pro CNP ELISA. The immunoassay is calibrated against recombinant NT-proCNP peptide:
NT-proCNP ELISA Kit Components
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CONT |
KIT COMPONENTS |
QUANTITY |
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PLATE |
Polyclonal sheep anti-NT-proCNP antibody pre-coated microtiter strips in strip holder, packed in an aluminum bag with desiccant |
12 x 8 tests |
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WASHBUF |
Wash buffer concentrate 20x, natural cap |
1 x 50 ml |
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STD |
Standards 1-7, (0; 4; 8; 16; 32; 64; 128 pmol/l), recombinant NT-proCNP in human serum, white caps, lyophilized |
7 vials |
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CTRL |
Control A + B, yellow caps, lyophilized, exact concentrations see labels |
2 vials |
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ASYBUF |
Assay buffer, red cap, ready to use |
1 x 8 ml |
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CONJ |
Conjugate (polyclonal sheep anti-NT-proCNP-HRP), amber cap, ready to use |
1 x 7 ml |
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SUB |
Substrate (TMB solution), amber bottle, blue cap, ready to use |
1 x 13 ml |
| STOP |
Stop solution, white cap, ready to use |
1 x 7 ml |
Storage instructions: All reagents of the NT-proCNP ELISA kit are stable at +4°C (+2-8 °C) until the expiry date stated on the label of each reagent.
Serum, EDTA plasma, heparın plasma, citrate plasma, cell culture supernatant and urine are suitable for use in this assay. Do not change sample type during studies. We recommend duplicate measurements for all samples, standards and controls. The sample collection and storage conditions listed are intended as general guidelines.
Serum & Plasma
Collect venous blood samples in standardized serum separator tubes (SST) or standardized blood collection tubes using EDTA, heparın or citrate as an anticoagulant. For serum samples, allow samples to clot for 30 minutes at room temperature. Perform separation by centrifugation according to the tube manufacturer’s instructions for use. Assay the acquired samples immediately or aliquot and store at -25°C or lower. Lipemic or haemolyzed samples may give erroneous results. Do not freeze-thaw samples more than five times.
Urine
Note: the experiments performed to measure NT-proCNP in urine samples did not undergo a full validation according to ICH guidelines. However, our performance check suggests that urine samples can be measured with this ELISA. For more information please see our validation data tab.
Aseptically collect the first urine of the day (mid-stream), voided directly into a sterile container. Centrifuge to remove particulate matter, assay immediately or aliquot and store at -25°C or lower.
Cell Culture Supernatant
Note: the experiments performed to measure NT-proCNP in urine samples did not undergo a full validation according to ICH guidelines. However, our performance check suggests that urine samples can be measured with this ELISA. For more information please see our validation data file.
Remove particulates by centrifugation and assay immediately or aliquot and store samples at
-25°C or lower. Do not freeze-thaw samples more than five times.
Reagent Preparation
Wash Buffer
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1. |
Bring the WASHBUF concentrate to room temperature. Crystals in the buffer concentrate will dissolve at room temperature. |
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2. |
Dilute the WASHBUF concentrate 1:20, e.g. 50 ml WASHBUF + 950 ml distilled or deionized water. Only use diluted WASHBUF when performing the assay. |
The diluted WASHBUF is stable up to one month at 4°C (2-8°C).
Standards for Serum & Plasma Measurements
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1. |
Pipette 300 µl of distilled or deionized water into each standard (STDs) and control (CTRL) vial. The exact concentration is printed on the label of each vial. |
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2. |
Leave at room temperature (18-26°C) for 15 min. Vortex gently. |
Reconstituted STDs and CTRLs are stable at -25°C or lower until expiry date stated on the label. STDs and CTRLs are stable for three freeze-thaw cycles.
Standards for Cell Culture Supernatant Measurements
For the preparation of cell culture-based standards always use the identical cell culture medium (CCM) as used for the experiment.
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1. |
Reconstitute standard 7 (STD7) in 300 µl deionized water. Leave at room temperature (18-26°C) for 15 min and mix well before making dilutions. Use polypropylene tubes. |
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2. |
Mark tubes ccSTD6 to ccSTD1. Dispense 100 µl cell culture medium into each vial. |
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3. |
Pipette 100 µl of STD7 into tube marked as ccSTD6. Mix thoroughly. |
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4. |
Transfer 100 µl of ccSTD6 into the tube marked as ccSTD5. Mix thoroughly. |
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5. |
Continue in the same fashion to obtain ccSTD4 to ccSTD2. CCM serves as the ccSTD1 (0 pmol/l NT-proCNP). |
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6. |
Using the prepared standards, follow the protocol as indicated for serum, plasma and urine samples. |
Attention: Supplied STD1-STD7 and controls are only valid for serum and should not be used for cell culture measurements.
Sample Preparation
Bring samples to room temperature and mix samples gently to ensure the samples are homogenous.
We recommend duplicate measurements for all samples.
Samples for which the OD value exceeds the highest point of the standard range can be diluted 1+1 with ASYBUF (assay buffer).
NT-proCNP ELISA Assay Protocol
Read the entire protocol before beginning the assay.
|
1. |
Bring reagents and samples to room temperature (18-26°C). |
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2. |
Mark position for STD/CTRL/SAMPLE (standard/control/sample) on the protocol sheet. |
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3. |
Take microtiter strips out of the aluminum bag. Store unused strips with desiccant at 4°C in the aluminum bag. Strips are stable until the expiry date stated on the label. |
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4. |
Pipette 50 µl ASYBUF (assay buffer, red cap) into each well. |
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5. |
Add 20 µl STD/CTRL/SAMPLE into the respective wells. Swirl gently. |
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6. |
Cover the plate tightly and incubate for 20 minutes at room temperature. |
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7. |
Add 50 µl CONJ (conjugate) into each well, swirl gently. |
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8. |
Cover tightly and incubate for 3 hours at room temperature in the dark. |
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9. |
Aspirate and wash wells 5x with 300 µl diluted WASHBUF (wash buffer). After the final wash, remove remaining WASHBUF by strongly tapping plate against a paper towel. |
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10. |
Add 100 µl SUB (substrate, blue cap) into each well. |
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11. |
Incubate for 30 min at room temperature in the dark. |
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12. |
Add 50 µl STOP (stop solution, white cap) into each well, swirl gently. |
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13. |
Measure absorbance immediately at 450 nm with reference 630 nm, if available. |
Calculation of Results
Read the optical density (OD) of all wells on a plate reader using 450 nm wavelength (reference wavelength 630 nm). Construct a standard curve from the absorbance read-outs of the standards using commercially available software capable of generating a four-parameter logistic (4-PL) fit. Alternatively, plot the standards’ concentration on the x-axis against the mean absorbance for each standard on the y-axis and draw a best fit curve through the points on the graph. Curve fitting algorithms other than 4-PL have not been validated and will need to be evaluated by the user.
Obtain sample concentrations from the standard curve. If required, pmol/l can be converted into pg/ml by applying a conversion factor (1 pg/ml = 0.201 pmol/l (MW: 4.985 kDa)). Respective dilution factors have to be considered when calculating the final concentration of the sample.
The quality control (QC) protocol supplied with the kit shows the results of the final release QC for each kit at production date. Data for OD obtained by customers may differ due to various influences and/or due to the normal decrease of signal intensity during shelf life. However, this does not affect validity of results as long as an OD of 1.50 or more is obtained for the STD7 and the value of the CTRL is in range (target range see label).
NT-proCNP Protein
C–type natriuretic peptide (CNP) is a paracrine growth factor widely expressed in various tissues. The 103-amino acid propeptide is cleaved either between residues 50 and 51 or 81 and 82 to produce one of two biologically active peptides, carboxy-terminal proCNP (51–103) or carboxy-terminal proCNP (82–103), respectively, and an amino-terminal congener, N-terminal proCNP.
From: Natriuretic Peptides, Their Receptors, and Cyclic Guanosine Monophosphate-Dependent Signaling Functions. Potter LR et al., 2006; Endocrine Reviews 27(1):47–72. doi: 10.1210/er.2005-0014
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Molecular weight |
4.985 kDa |
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Cellular localisation |
Secreted |
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Post-translational modifications |
Glycosylation, disulphide bonds |
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Sequence similarities |
Natriuretic peptide family |
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Alternative names |
CNP2, CNP, Natriuretic Peptide Precursor Type C, C-type Natriuretic Peptide, Natriuretic Peptide C |
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Pubchem ID |
4990 link: https://www.ncbi.nlm.nih.gov/gene/4880 |
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Genecards |
NPPC link: https://www.genecards.org/cgi-bin/carddisp.pl?gene=NPPC |
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PDB |
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OMIM |
600296 link: https://www.omim.org/entry/600296 |
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Protein Atlas |
NPPC link: https://www.proteinatlas.org/ENSG00000163273-NPPC/tissue |
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Uniprot ID |
P23582 link: https://www.uniprot.org/uniprot/P23582 |
NT-proCNP Function
C–type natriuretic peptide (CNP) is a paracrine growth factor widely expressed in tissues, including the vascular endothelium, where it is considered to provide vasoprotective functions. In endothelial cells and macrophages, it is secreted in response to several stimuli, including inflammatory mediators. CNP is rapidly degraded in tissues and negligible quantities enter the circulation. However, the N-terminal portion of the pro-hormone is not degraded at source and circulates in significantly higher concentrations than CNP. Therefore NT-proCNP is a valuable biomarker to determine CNP synthesis in tissues. CNP plays a critical role in linear growth. It is produced in the growth plate and signals through a paracrine mechanism. Recent studies have shown that the plasma concentrations of NT-proCNP correlate with linear growth velocity in all phases of skeletal growth and increase during rhGH (growth hormone) therapy (Olney et al., 2016). Furthermore, serum NT-proCNP levels increased after initiation of GH treatment in patients with achondroplasia/ hypochondroplasia (Kubota et al., 2016). Women with pregnancy complications, such as diminished fetal growth and pre-eclampsia show significantly increased NT-proCNP levels early in gestation (Espiner et al., 2015; Reid et al., 2014). NT-proCNP concentration at hospital admission has sufficient sensitivity and specificity to differentiate naturally occurring sepsis from non-septic systemic inflammatory response syndrome (SIRS) (Koch et al., 2012; Tomasiuk et al., 2014). Recently, Prickett and colleagues demonstrated in a cohort of over 2000 individuals, that in contrast to the close association of NT-proBNP with cardiac function, and predictive value for outcome after myocardial infarction, plasma NT-proCNP is highly correlated with renal function and is an independent predictor of mortality and cardiac readmission in individuals with unstable angina (Volpe et al., 2015).
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Cancer
Prostate cancer (Lippert et al., 2015)
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Heart & Cardiovascular disease
Coronary heart disease (Guclu et al., 2017; Prickett et al., 2017)
Chronic heart failure (Cabiati et al., 2013)
Postural tachycardia syndrome (Lin et al., 2015)
Angina (Prickett et al., 2017; Volpe et al., 2015)
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Other
Parkinson (Espiner et al., 2014; Woodward et al., 2017)
Hepatitis related liver disease (Abdelkader et al., 2015)
Cirrhosis (Koch et al., 2012)
Complicated pregnancy and preeclampsia (Espiner et al., 2015; Reid et al., 2014)
Sepsis (Koch et al., 2012; Tomasiuk et al., 2014)
Literature
Mutations in C-natriuretic peptide (NPPC): a novel cause of autosomal dominant short stature.
Hisado-Oliva, A., Ruzafa-Martin, A., Sentchordi, L., Funari, M.F.A., Bezanilla-López, C., Alonso-Bernáldez, M., Barraza-García, J., Rodriguez-Zabala, M., Lerario, A.M., Benito-Sanz, S., Aza-Carmona, M., Campos-Barros, A., Jorge, A.A.L., Heath, K.E., 2018. Genet. Med. Off. J. Am. Coll. Med. Genet. 20, 91–97.
PMID: 28661490
Evaluation of Pericardial Fluid C-Type Natriuretic Peptide Levels in Patients Undergoing Coronary Bypass Surgery.
Guclu, O., Karahan, O., Karabacak, M., Yuksel, V., Huseyin, S., Mavitas, B., 2017. Thorac. Cardiovasc. Surg. 65, 311–314.PMID: 26962968
C-Type Natriuretic Peptides in Coronary Disease.
Prickett, T.C.R., Doughty, R.N., Troughton, R.W., Frampton, C.M., Whalley, G.A., Ellis, C.J., Espiner, E.A., Richards, A.M., 2017. Clin. Chem. 63, 316–324.PMID: 28062626
Central and systemic C-type Natriuretic Peptide are both reduced in Parkinson’s Disease.
Woodward, Z., Prickett, T.C.R., Espiner, E.A., Anderson, T.J., 2017. Parkinsonism Relat. Disord. 43, 15–19.PMID: 28673612
C-type natriuretic peptide is closely associated to obesity in Caucasian adolescents.
Del Ry, S., Cabiati, M., Bianchi, V., Caponi, L., Maltinti, M., Caselli, C., Kozakova, M., Palombo, C., Morizzo, C., Marchetti, S., Randazzo, E., Clerico, A., Federico, G., 2016. Clin. Chim. Acta Int. J. Clin. Chem. 460, 172–177.PMID: 27376982
Serum NT-proCNP levels increased after initiation of GH treatment in patients with achondroplasia/hypochondroplasia.
Kubota, T., Wang, W., Miura, K., Nakayama, H., Yamamoto, K., Fujiwara, M., Ohata, Y., Tachibana, M., Kitaoka, T., Takakuwa, S., Miyoshi, Y., Namba, N., Ozono, K., 2016. Clin. Endocrinol. (Oxf.) 84, 845–850.PMID: 26814021
Dynamic response of C-type natriuretic peptide and its aminoterminal propeptide (NTproCNP) to growth hormone treatment in children with short stature.
Olney, R.C., Salehi, P., Prickett, T.C.R., Lima, J.J., Espiner, E.A., Sikes, K.M., Geffner, M.E., 2016. Clin. Endocrinol. (Oxf.) 85, 561–568.PMID: 27177682
CLINICAL SIGNIFICANCE OF SERUM N-TERMINAL PRO C-TYPE NATRIURETIC PEPTIDE IN HEPATITIS C-RELATED CHRONIC LIVER DISEASES.
Abdelkader, N.A., Zaki, M., Saad, W.E., Hamdy, G., Sabry, D., 2015. J. Egypt. Soc. Parasitol. 45, 219–226PMID: 26485840
Effects of pre-eclampsia and fetal growth restriction on C-type natriuretic peptide.
Espiner, E.A., Prickett, T.C.R., Taylor, R.S., Reid, R.A., McCowan, L.M., 2015. BJOG Int. J. Obstet. Gynaecol. 122, 1236–1243.PMID: 25846957
Skeletal overgrowth syndrome caused by overexpression of C-type natriuretic peptide in a girl with balanced chromosomal translocation, t(1;2)(q41;q37.1).
Ko, J.M., Bae, J.-S., Choi, J.S., Miura, K., Lee, H.R., Kim, O.-H., Kim, N.K.D., Oh, S.K., Ozono, K., Lee, C.-K., Choi, I.H., Park, W.-Y., Cho, T.-J., 2015. Am. J. Med. Genet. A. 167A, 1033–1038.PMID: 25728306
Plasma C-type natriuretic peptide as a predictor for therapeutic response to metoprolol in children with postural tachycardia syndrome.
Lin, J., Han, Z., Li, H., Chen, S.Y., Li, X., Liu, P., Wang, Y., Tang, C., Du, J., Jin, H., 2015. PloS One 10, e0121913.PMID: 25811760; PMCID: PMC4374798
C-type natriuretic peptide and its precursor: potential markers in human prostate cancer.
Lippert, S., Iversen, P., Brasso, K., Goetze, J.P., 2015. Biomark. Med. 9, 319–326.PMID: 25808436
C-type natriuretic peptide plasma levels are elevated in subjects with achondroplasia, hypochondroplasia, and thanatophoric dysplasia.
Olney, R.C., Prickett, T.C.R., Espiner, E.A., Mackenzie, W.G., Duker, A.L., Ditro, C., Zabel, B., Hasegawa, T., Kitoh, H., Aylsworth, A.S., Bober, M.B., 2015. J. Clin. Endocrinol. Metab. 100, E355-359.PMID: 25387261
The natriuretic peptides system in the pathophysiology of heart failure: from molecular basis to treatment.
Volpe, M., Carnovali, M., Mastromarino, V., 2015. Clin. Sci. 130, 57–77.
C-type natriuretic peptide in Parkinson’s disease: reduced secretion and response to deprenyl.
Espiner, E.A., Dalrymple-Alford, J.C., Prickett, T.C.R., Alamri, Y., Anderson, T.J., 2014. J. Neural Transm. Vienna Austria 1996 121, 371–378.PMID: 24306276
C-type natriuretic peptide in complicated pregnancy: increased secretion precedes adverse events.
Reid, R.A., Prickett, T.C.R., Pullar, B.E., Darlow, B.A., Gullam, J.E., Espiner, E.A., 2014. J. Clin. Endocrinol. Metab. 99, 1470–1478.PMID: 24446655
The prognostic value of concomitant assessment of NT-proCNP, C-reactive protein, procalcitonin and inflammatory cytokines in septic patients.
Tomasiuk, R., Mikaszewska-Sokolewicz, M., Szlufik, S., Rzepecki, P., Lazowski, T., 2014. Crit. Care Lond. Engl. 18, 440.PMID: 25043511; PMCID: PMC4075259
C-type natriuretic peptide transcriptomic profiling increases in human leukocytes of patients with chronic heart failure as a function of clinical severity.
Cabiati, M., Sabatino, L., Caruso, R., Verde, A., Caselli, C., Prescimone, T., Giannessi, D., Del Ry, S., 2013. Peptides 47, 110–114.PMID: 23911666
Acute inflammation in young children inhibits C-type natriuretic peptide.
Prickett, T.C.R., Hector-Taylor, J., Olney, R.C., Darlow, B.A., Espiner, E.A., 2013. Pediatr. Res. 74, 191–195.PMID: 23732776
Serum NT-proCNP concentrations are elevated in patients with chronic liver diseases and associated with complications and unfavorable prognosis of cirrhosis.
Koch, A., Zimmermann, H.W., Baeck, C., Schneider, C., Yagmur, E., Trautwein, C., Tacke, F., 2012. Clin. Biochem. 45, 429–435.
C-type natriuretic peptide and overgrowth.
Bocciardi, R., Ravazzolo, R., 2009. Endocr. Dev. 14, 61–66.PMID: 19293575
Comparison of serum and heparınized plasma samples for measurement of chemistry analytes.
Miles, R.R., Roberts, R.F., Putnam, A.R., Roberts, W.L., 2004. Clin. Chem. 50, 1704–1706.PMID: 15331516
PMID: 28661490All Biomedica ELISAs are validated according to international FDA/ICH/EMEA guidelines. For more information about our validation guidelines, please refer to our quality page and published validation guidelines and literature.
Calibration
This immunoassay is calibrated against synthetic human propeptide of CNP (AA 24-73 of Uniprot ID P23582, i.e. NT-proCNP 1-50).
NT-proCNP ELISA Detection Limit & Sensitivity
To determine the sensitivity of the human total NT-proCNP ELISA, experiments measuring the lower limit of detection (LOD) and the lower limit of quantification (LLOQ) were conducted.
The LOD, also called the detection limit, is the lowest point at which a signal can be distinguished above the background signal, i.e. the signal that is measured in the absence of NT-proCNP, with a confidence level of 99%. It is defined as the mean back calculated concentration of NT-proCNP-free sample (three independent measurements) plus three times the standard deviation of the measurements.
The LLOQ, or sensitivity of an assay, is the lowest concentration at which an analyte can be accurately quantified. The criteria for accurate quantification at the LLOQ are an analyte recovery between 75 and 125% and a coefficient of variation (CV) of less than 25%. The lowest concentration of NT-proCNP, which meets both criteria, is reported as the LLOQ.
The following values were determined for the NT-proCNP human ELISA:
|
LOD |
0.7 pmol/l |
|
LLOQ |
0.5 pmol/l |
NT-proCNP ELISA Precision
The precision of an ELISA is defined as its ability to measure the same concentration consistently within the same experiments carried out by one operator (within-run precision or repeatability) and across several experiments using the same samples but conducted by several operators at different locations using different ELISA lots (in-between-run precision or reproducibility).
Within-Run Precision
Samples of known concentration were tested five times to assess within-run precision, also called intra-assay precision. The experiment was performed by one operator using a single plate.
|
Within-Run Precision |
||
|
Sample |
#1 |
#2 |
|
n |
5 |
5 |
|
Mean NT-proCNP [pmol/l] |
7.9 |
65.3 |
|
Standard deviation |
0.47 |
1.25 |
|
% CV |
6 |
2 |
In-Between-Run Precision
Samples of known concentration were tested eight times to assess in-between-run precision, also called inter-assay precision. The experiment was performed by multiple operators using plates and kit components from two lots.
|
Within-Run Precision |
||
|
Sample |
#1 |
#2 |
|
n |
8 |
8 |
|
Mean NT-proCNP [pmol/l] |
8.2 |
64.1 |
|
Standard deviation |
0.54 |
1.42 |
|
% CV |
7 |
2 |
NT-proCNP ELISA Accuracy
The accuracy of an ELISA is defined as the precision with which it can recover samples of known concentrations.
The recovery of the total NT-proCNP ELISA was measured by adding recombinant NT-proCNP to human samples containing a known concentration endogenous NT-proCNP. The %recovery of the spiked concentration was calculated as the percentage of measured compared over the expected value.
This table shows the summary of the recovery experiments in the NT-proCNP ELISA in different sample matrices:
|
% Recovery |
|||||
|
Sample Matrix |
n |
+12.8 pmol/l |
+64 pmol/l |
||
|
Mean |
Range |
Mean |
Range |
||
|
Serum |
6 |
102 | 91-115 | 101 | 96-105 |
|
EDTA plasma |
6 |
99 | 80-116 | 99 | 94-101 |
|
Citrate plasma |
2 |
100 | 94-106 | 100 | 97-103 |
|
Heparın plasma |
2 |
92 | 90-94 | 93 | 92-95 |
Data showing recovery of NT-proCNP in human serum samples:
|
|
NT-proCNP [pmol/l] |
% Recovery |
||||
|
Sample Matrix |
ID |
Reference |
+ 12.8 pmol/l |
+ 64 pmol/l |
+ 12.8 pmol/l |
+ 64 pmol/l |
|
Serum |
S1 |
32.4 | 42.3 | 83.6 | 103 | 105 |
|
Serum |
S2 |
34.4 | 42.6 | 81.1 | 91 | 100 |
|
Serum |
S3 |
20.5 | 30.7 | 74.8 | 95 | 101 |
|
Serum |
S4 |
24.0 | 34.4 | 73.8 | 100 | 96 |
|
Serum |
S5 |
28.5 | 39.6 | 79.9 | 109 | 103 |
|
Serum |
S6 |
25.5 |
37.7 |
78.6 |
115 |
103 |
|
|
|
|
|
Mean |
102 | 101 |
|
|
|
|
|
Min |
91 | 96 |
|
|
|
|
|
Max |
115 | 105 |
Data showing recovery of NT-proCNP in human EDTA plasma samples:
|
|
NT-proCNP [pmol/l] |
% Recovery |
||||
|
Sample Matrix |
ID |
Reference |
+ 12.8 pmol/l |
+ 64 pmol/l |
+ 12.8 pmol/l |
+ 64 pmol/l |
|
EDTA plasma |
e1 |
29.0 | 36.3 | 78.7 | 80 | 100 |
|
EDTA plasma |
e2 |
31.5 | 43.1 | 78.9 | 116 | 99 |
| EDTA plasma |
e3 |
25.3 | 35.5 | 77.2 | 99 | 101 |
| EDTA plasma |
e4 |
28.4 | 38.7 | 78.2 | 103 | 100 |
| EDTA plasma |
e5 |
27.7 | 38.0 | 73.9 | 102 | 94 |
| EDTA plasma |
e6 |
21.3 | 30.9 | 74.4 | 92 | 100 |
|
|
|
|
|
Mean |
99 | 99 |
|
|
|
|
|
Min |
80 | 94 |
|
|
|
|
|
Max |
116 | 101 |
Data showing recovery of NT-proCNP in human heparın plasma samples:
|
|
NT-proCNP [pmol/l] |
% Recovery |
||||
|
Sample Matrix |
ID |
Reference |
+ 12.8 pmol/l |
+ 64 pmol/l |
+ 12.8 pmol/l |
+ 64 pmol/l |
|
Heparın plasma |
h1 |
28 | 37 | 75 | 90 | 95 |
|
Heparın plasma |
h2 |
30 | 39 | 74 | 94 | 92 |
|
|
|
|
|
Mean |
92 | 93 |
Data showing recovery of NT-proCNP in human citrate plasma samples:
|
NT-proCNP [pmol/l] |
% Recovery |
|||||
|
Sample Matrix |
ID |
Reference |
+ 12.8 pmol/l |
+ 64 pmol/l |
+ 12.8 pmol/l |
+ 64 pmol/l |
|
Citrate plasma |
c1 |
24 |
35 |
78 |
106 |
103 |
|
Citrate plasma |
c2 |
29 |
38 |
77 |
94 |
97 |
|
Mean |
100 |
100 |
||||
NT-proCNP ELISA Dilution Linearity & Parallelism
Tests of dilution linearity and parallelism ensure that both endogenous and recombinant samples containing NT-proCNP behave in a dose dependent manner and are not affected by matrix effects. Dilution linearity assesses the accuracy of measurements in diluted human samples spiked with known concentrations of recombinant analyte. By contrast, parallelism refers to dilution linearity in human samples and provides evidence that the endogenous analyte behaves the same way as the recombinant one. For dilution linearity and parallelism are assessed for each sample type and are considered acceptable if the results are within 20% of the expected concentration.
The table below shows the mean recovery of recombinant NT-proCNP in serum and plasma serially diluted with STD1:
| % Recovery of recombinant NT-proCNP in diluted samples | |||||||||
| Sample Matrix | n | 1+1 | 1+3 | 1+7 | 1+15 | ||||
| Mean | Range | Mean | Range | Mean | Range | Mean | Range | ||
| Serum | 6 | 93 | 89-97 | 89 | 78-97 | 86 | 78-100 | 99 | 89-118 |
| EDTA plasma | 6 | 99 | 95-102 | 95 | 89-102 | 93 | 84-101 | 97 | 85-111 |
| Heparın plasma | 2 | 102 | 94-111 | 100 | 94-105 | 92 | 84-99 | 93 | 90-96 |
| Citrate plasma | 2 | 95 | 94-97 | 93 | 89-96 | 87 | 84-90 | 99 | 98-100 |
Parallelism was assessed by serially diluting human samples containing endogenous NT-proCNP with STD1, i.e., human serum containing 0 pmol/l NT-proCNP.
The table below shows the mean recovery and range of serially diluted endogenous NT-proCNP in several sample matrices:
| % Recovery of endogenous NT-proCNP in diluted samples | |||||
| Sample Matrix | n | 1+1 | 1+3 | ||
| Mean | Range | Mean | Range | ||
| Serum | 6 | 99 | 96-102 | 98 | 93-119 |
| EDTA plasma | 6 | 103 | 98-110 | 98 | 92-104 |
| Heparın plasma | 2 | 96 | 94-98 | 92 | 86-98 |
| Citrate plasma | 2 | 100 | 98-103 | 100 | 97-102 |
Data showing dilution linearity of endogenous NT-proCNP in human serum samples:
| NT-proCNP [pmol/l] | % Recovery | |||||
| Sample Matrix | Reference | 1+1 | 1+3 | 1+1 | 1+3 | |
| Serum | s1 | 32.4 | 15.6 | 7.6 | 96 | 94 |
| Serum | s2 | 34.4 | 17.2 | 8.0 | 100 | 93 |
| Serum | s3 | 20.5 | 10.1 | 4.9 | 99 | 94 |
| Serum | s4 | 24.0 | 11.5 | 5.6 | 96 | 94 |
| Serum | s5 | 28.5 | 14.1 | 6.8 | 99 | 96 |
| Serum | s6 | 25.5 | 13.0 | 7.6 | 102 | 119 |
| Mean | 99 | 98 | ||||
| Min | 96 | 93 | ||||
| Max | 102 |
119 | ||||
Data showing dilution linearity of endogenous NT-proCNP in human EDTA plasma samples:
| NT-proCNP [pmol/l] | % Recovery | |||||
| Sample Matrix | Reference | 1+1 | 1+3 | 1+1 | 1+3 | |
| EDTA plasma | e1 | 29.0 | 14.3 | 6.9 | 99 | 95 |
| EDTA plasma | e2 | 31.5 | 17.4 | 8.2 | 110 | 104 |
| EDTA plasma | e3 | 25.3 | 12.8 | 6.1 | 101 | 97 |
| EDTA plasma | e4 | 28.4 | 13.9 | 6.5 | 98 | 92 |
| EDTA plasma | e5 | 27.7 | 15.2 | 7.1 | 110 | 102 |
| EDTA plasma | e6 | 21.3 | 10.7 | 5.2 | 101 | 98 |
| Mean | 103 | 98 | ||||
| Min | 98 | 92 | ||||
| Max | 110 | 104 | ||||
Data showing dilution linearity of endogenous NT-proCNP in human heparın plasma samples:
| NT-proCNP [pmol/l] | % Recovery | |||||
| Sample Matrix | Reference | 1+1 | 1+3 | 1+1 | 1+3 | |
| Heparın plasma | h1 | 28.1 | 13.7 | 6.8 | 98 | 97 |
| Heparın plasma | h2 | 29.7 | 15.3 | 7.6 | 103 | 102 |
| Mean | 100 | 100 | ||||
Data showing dilution linearity of endogenous NT-proCNP in human citrate plasma samples:
| NT-proCNP [pmol/l] | % Recovery | |||||
| Sample Matrix | Reference | 1+1 | 1+3 | 1+1 | 1+3 | |
| Citrate plasma | c1 | 24.1 | 11.4 | 6.9 | 94 | 86 |
| Citrate plasma | c2 | 28.8 | 14.1 | 5.2 | 98 | 98 |
| Mean | 96 | 92 | ||||
NT-proCNP ELISA Specificity
This assay recognizes endogenous (natural) and synthetic human NT-proCNP.
Sample Stability
Sample preparation
Collect venous blood samples by using standardized blood collection tubes for serum or plasma. Perform serum and plasma separation by centrifugation according to supplier’s instructions of the blood collection devices as soon as possible.
The acquired serum or plasma samples should be measured as soon as possible. For longer storage aliquot samples and store at -25°C or lower.
Freeze-Thaw of Serum Samples Containing Endogenous NT-proCNP
A set of samples (3 sera, 3 EDTA plasma, 2 citrate plasma) was aliquoted and freeze-thaw stressed. The reference samples are freeze-thawed once. The mean recovery of sample concentrations stressed by four freeze-thaw (F/T) cycles is 96%.
The table below shows NT-proCNP concentrations of samples after four freeze-thaw cycles:
|
NT-proCNP [pmol/l] |
% Recovery 4 F/T vs ref |
||||
|
Sample ID |
Reference |
2x |
3x |
4x |
|
|
#S1 |
16.0 |
15.9 |
16.1 |
15.6 |
98 |
|
#S2 |
55.1 |
52.3 |
52.2 |
51.3 |
93 |
|
#S3 |
21.0 |
20.5 |
18.9 |
20.8 |
99 |
|
#E1 |
14.2 |
14.6 |
14.3 |
13.3 |
94 |
|
#E2 |
10.7 |
10.8 |
10.4 |
9.6 |
90 |
|
#E3 |
15.1 |
17.4 |
15.6 |
16.8 |
112 |
|
#C1 |
14.6 |
13.0 |
13.1 |
13.4 |
92 |
|
#C2 |
16.2 |
15.3 |
15.6 |
15.4 |
95 |
|
Mean |
96 |
||||
According to our data, samples can undergo at least four freeze-thaw cycles.
Sample Values
NT-proCNP Values in Apparently Healthy Donors
NT-proCNP reference ranges were established using serum and plasma samples from apparently healthy donors. No medical histories were available for the volunteers.
|
Sample Matrix |
n |
Median [pmol/l] |
Range [pmol/l] |
|
Serum |
32 |
14.5 |
5 - 34 |
|
EDTA plasma |
33 |
15.0 |
8 - 29 |
|
Heparın plasma |
18 |
13.5 |
8 - 27 |
|
Citrate plasma |
18 |
12.0 |
8 - 25 |
We recommended establishing the normal range for each laboratory.
NT-proCNP Values in an Unselected Hospital Panel
NT-proCNP was measured in plasma samples of patients from an unselected hospital panel:
|
Cohort |
Sample Matrix |
n |
Median NT-proCNP [pmol/l] |
Range [pmol/l] |
|
Unselected hospital panel |
Citrate plasma |
8 |
14 |
9 - 17 |
|
Unselected hospital panel |
EDTA plasma |
8 |
19 |
15 - 26 |
|
Unselected hospital panel |
Heparın plasma |
8 |
16 |
11 - 28 |
The figures below show the distribution of NT-proCNP concentrations in an unselected hospital panel compared to samples from apparently healthy donors:
Matrix Comparison
Human NT-proCNP sample concentrations were compared between serum, EDTA plasma, and citrate plasma from an apparently healthy cohort (n=16):
|
|
NT-proCNP [pmol/l] |
|||
|
Donor ID |
EDTA plasma |
Citrate plasma |
Heparın plasma |
Serum |
|
#1 |
17 |
14 |
16 |
20 |
|
#2 |
17 |
16 |
18 |
21 |
|
#3 |
13 |
11 |
12 |
16 |
|
#4 |
14 |
12 |
12 |
15 |
|
#5 |
16 |
17 |
18 |
22 |
|
#6 |
22 |
19 |
21 |
24 |
|
#7 |
15 |
13 |
14 |
19 |
|
#8 |
14 |
12 |
13 |
16 |
|
#9 |
15 |
11 |
12 |
16 |
|
#10 |
11 |
9 |
9 |
14 |
|
#11 |
24 |
20 |
22 |
28 |
|
#12 |
14 |
11 |
12 |
15 |
|
#13 |
13 |
10 |
10 |
14 |
|
#14 |
10 |
8 |
8 |
11 |
|
#15 |
28 |
23 |
26 |
34 |
|
#16 |
29 |
25 |
27 |
34 |
The measurements show that values of human NT-proCNP are higher in serum compared to plasma. In previous studies, it was shown that sample values for serum and plasma can differ for the measurement of chemistry analytes.
|
|
NT-proCNP [pmol/l] |
% CV |
||||
|
Donor ID |
Serum |
EDTA plasma |
Citrate plasma |
Heparın plasma |
All matrices |
Only plasma |
|
#1 |
2.3 |
1.6 |
1.8 |
2.3 |
16 |
16 |
|
#2 |
2.6 |
1.8 |
1.9 |
2.4 |
15 |
11 |
|
#3 |
2.0 |
1.1 |
1.5 |
1.7 |
22 |
19 |
|
#4 |
1.9 |
1.2 |
1.3 |
1.7 |
19 |
15 |
|
#5 |
2.0 |
1.6 |
1.8 |
1.9 |
8 |
6 |
|
#6 |
3.7 |
2.6 |
2.7 |
3.2 |
14 |
8 |
|
#7 |
1.5 |
1.2 |
1.2 |
1.4 |
8 |
6 |
|
#8 |
1.5 |
1.0 |
1.4 |
1.6 |
16 |
19 |
|
Mean |
15 |
13 |
||||
Graph showing NT-proCNP levels dependence of sample concentrations on sample matrix:
Measurement of NT-proCNP in Cell Culture Supernatant
Note: the experiments performed to measure NT-proCNP in cell culture supernatants are not a full validation but are merely a performance check.
Cell culture medium (ccm: RPMI1640 containing 10% fetal calf serum) was tested undiluted and spiked with a final concentration of 64 pmol/l synthetic human NT-proCNP. The spiked solution was diluted 1+1, 1+3, 1+7 with the cell culture medium.
As a comparison, the spike recovery and dilution linearity of the standard matrix (=STD1) and the dilutions with assay buffer is shown.
OD values of spiked and diluted cell culture medium sample and standard matrix (STD1):
| OD | |||||||
|
Dilution medium |
Sample ID |
Reference |
+ 64 pmol/l |
1+1 |
1+3 |
1+7 |
1+15 |
|
ccm |
ccm |
0.028 |
1.355 |
0.627 |
0.290 |
0.125 |
0.072 |
|
ASYBUF |
STD1 |
0.031 |
1.271 |
0.601 |
0.318 |
0.156 |
0.090 |
Graph showing dilution of cell culture medium (ccm) and a comparison to the Standard (STD1), both spiked with the same amount of synthetic NT-proCNP (64 pmol/l).
Measurement of NT-proCNP in Urine
The ELISA has not been fully validated for the measurement of human NT-proCNP in urine samples but can be used for this sample matrix.
Undiluted human urine samples from apparently healthy subjects and from patients with kidney disease were tested.
Summary
Urine samples (n=48) were assayed with the Biomedica NT-proCNP ELISA (BI-20812) following the standard protocol using undiluted urine.
- Endogenous NT-proCNP was detectable in samples from kidney patients.
- Urine samples can be spiked – the average recovery of 8 human urine samples is 109%.
- If required, dilute urine samples 1+1 with assay buffer. Dilution linearity of samples containing high values of endogenous NT-proCNP (n=2) with assay buffer is 103%.
Specificity was assessed by adding the coating antibody utilized in the NT-proCNP ELISA assay to urine samples containing elevated endogenous NT-proCNP levels (n=2). The samples showed a competition of 93%.
Recovery
Recovery was assessed by adding STD7 (final concentration 64 pmol/l synthetic human NT-proCNP) directly to eight different human urine samples (ratio 1+1).
Data showing spike/recovery of human urine samples:
|
|
NT-proCNP c [pmol/l] |
||
|
Sample ID |
Reference |
+ 64 pmol/l |
% Recovery |
|
#U1 |
1 |
68 |
106 |
|
#U2 |
59 |
111 |
128 |
|
#U3 |
1 |
67 |
105 |
|
#U4 |
1 |
67 |
104 |
|
#U5 |
0 |
63 |
98 |
|
#U6 |
80 |
116 |
118 |
|
#U7 |
0 |
64 |
100 |
|
#U8 |
1 |
70 |
109 |
|
Mean |
109 |
||
Linearity
Dilution linearity was assessed by diluting urine samples containing endogenous NT-proCNP with ASYBUF (assay buffer supplied in the kit).
Data showing the dilution of endogenous NT-proCNP in urine samples:
|
NT-proCNP [pmol/l] |
% Recovery |
||
|
Sample ID |
Reference |
1+1 |
|
|
#U1 |
69 |
33 |
95 |
|
#U2 |
92 |
51 |
111 |
|
Mean |
103 |
||
Competition
Specificity was assessed by adding the coating antibody utilized in the NT-proCNP ELISA assay to urine samples containing elevated endogenous NT-proCNP levels.
Data showing the competition of the signal:
|
NT-proCNP [pmol/l] |
|||
|
Sample ID |
Reference |
Competition |
% Recovery |
|
#U1 |
69 |
6 |
91 |
|
#U2 |
92 |
4 |
96 |
|
Mean |
93 |
||
Comparison of panels from various donors:
|
Cohort |
n |
Median NT-proCNP [pmol/l] |
Range [pmol/l] |
|
Apparently healthy |
4 |
1 |
1 - 2 |
|
Kidney cohort I |
24 |
1 |
0 - 92 |
|
Kidney cohort II |
20 |
0 |
0 - 2 |
Measurement of NT-proCNP in Non-Human Samples
The sequence homology of NT-proCNP is very conserved among different species. We therefore assessed if the assay which is validated for human samples can be used in rat, mouse and pig samples. Other species types that share a high homology to human NT-proCNP can likely be measured with this assay (e.g. monkey, cats, dogs).
Note: the experiments performed for non-human species are not a full validation but are merely a performance check.
|
Uniprot ID |
Species |
% Sequence homology |
|
P23582 |
C-type natriuretic peptide Homo sapiens (Human) |
100 |
|
H2QJL6 |
PANTR - Uncharacterized protein - Pan troglodytes (Chimpanzee) |
98 |
|
H2P8X1 |
PONAB - Uncharacterized protein - Pongo abelii (Sumatran Orangutan) |
98 |
|
M3WH43 |
FELCA - Uncharacterized protein - Felis catus (Cat) |
96 |
|
E2R4X2 |
CANLF - Uncharacterized protein - Canis lupus family |
96 |
|
P18104 |
PIG - C-type natriuretic peptide Sus scrofa (Pig) |
94 |
|
P55207 |
RAT - C-type natriuretic peptide - Rattus norvegicus (Rat) |
92 |
|
Q9D288 |
MOUSE - Putative uncharacterized protein Mus musculus (Mouse) |
86 |
|
Q544K5 |
MOUSE - C-type natriuretic peptide (Mus musculus) |
86 |
|
Q61839 |
MOUSE - C-type natriuretic peptide Mus musculus (Mouse) |
86 |
|
A0A1L1WKH8 |
RAT - Natriuretic peptide C - Rattus norvegicus |
93 |
Measurement of NT-proCNP in Rat Samples
Rat NT-proCNP shares a 92% homology to human NT-proCNP.
According to our data, rat serum samples (n=8) showed a recovery of 97% and a linearity of 87%. The samples tested contained endogenous NT-proCNP concentrations between 9-38 pmol/ml. Competition of endogenous NT-proCNP concentrations from rat samples is 100%.
Linearity
Eight undiluted rat serum samples were tested in the NT-proCNP ELISA (note: standards contain synthetic human NT-proCNP spiked in a human serum matrix).
For linearity experiments, rat samples were diluted 1+1 with ASYBUF. The table below shows the recoveries relative to the expected concentrations of eight rat samples:
|
NT-proCNP |
||
|
Sample ID |
+ 64 pmol/l |
% Recovery |
|
#R1 |
68 |
94 |
|
#R2 |
76 |
95 |
|
#R3 |
76 |
95 |
|
#R4 |
68 |
99 |
|
#R5 |
78 |
101 |
|
#R6 |
81 |
97 |
|
#R7 |
74 |
97 |
|
#R8 |
66 |
97 |
|
Mean |
97 |
Recovery
For recovery experiments, STD7 was added to the rat serum samples in a ratio 1+1 (final concentration 64 pmol/l).
The table below shows the calculated concentrations and spike recovery of eight rat samples:
|
|
NT-proCNP [pmol/l] |
|
|
|
Sample ID |
Reference |
1+1 |
% Recovery |
|
#R1 |
16 |
8 |
95 |
|
#R2 |
32 |
13 |
83 |
|
#R3 |
31 |
11 |
72 |
|
#R4 |
10 |
5 |
101 |
|
#R5 |
26 |
11 |
84 |
|
#R6 |
38 |
15 |
79 |
|
#R7 |
23 |
10 |
85 |
|
#R8 |
9 |
4 |
93 |
|
Mean |
87 |
||
Competition
Specificity was assessed by adding the coating antibody utilized in the human NT-proCNP ELISA assay to the rat serum samples.
Data showing the competition of the signal:
|
|
NT-proCNP [pmol/l] |
|
|
|
Sample ID |
Reference |
+ Coating AB |
% Competition |
|
#R1 |
15 |
0 |
100 |
|
#R2 |
28 |
0 |
100 |
|
#R3 |
29 |
0 |
100 |
|
#R4 |
10 |
0 |
100 |
|
#R5 |
27 |
0 |
100 |
|
#R6 |
34 |
0 |
100 |
|
#R7 |
22 |
0 |
100 |
|
#R8 |
9 |
0 |
100 |
|
Mean |
100 |
||
Measurement of NT-proCNP in Mouse Samples
Mouse NT-proCNP shares an 86% homology to human NT-proCNP.
According to our data, mouse serum samples (n=8) showed an average recovery of 45% when spiked with STD7 in a ratio 1+1 (final concentration 64 pmol/l). The mouse samples tested did not contain endogenous NT-proCNP concentrations. Linearity was not tested.
Measurement of NT-proCNP in Pig Samples
Pig NT-proCNP shares a 94% homology to human NT-proCNP.
According to our data, pig serum samples (n=8) showed a recovery of 83%. The pig samples tested did not contain endogenous NT-proCNP concentrations. Linearity was not tested.
Recovery
Eight undiluted pig serum samples were tested in the NT-proCNP ELISA (note: standards contain synthetic human NT-proCNP spiked in a human serum matrix).
For Recovery experiments: STD7 was added to the pig serum samples in a ratio 1+1 (final concentration 64 pmol/l).
Calculation of pig sample concentrations, and spike recovery:
|
|
NT-proCNP [pmol/l] |
|
|
|
Sample ID |
Reference |
+ 64 pmol/l |
% Recovery |
|
#P1 |
0 |
58 |
91 |
|
#P2 |
0 |
57 |
89 |
|
#P3 |
0 |
55 |
85 |
|
#P4 |
0 |
55 |
86 |
|
#P5 |
0 |
52 |
81 |
|
#P6 |
0 |
51 |
80 |
|
#P7 |
0 |
48 |
75 |
|
#P8 |
0 |
50 |
78 |
|
Mean |
83 |
||
Comparison of NT-proCNP ELISA BI-20812 (2nd generation) vs BI-20872
The two NT-proCNP assays show a poor correlation due to the use of different reagents (e.g standard material, highly purified antibodies, and buffer solutions).
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PMID:26814021 - The evaluation of NT-proCNP, C-reactive protein and serum amyloid A protein concentration in patients with multiple myeloma undergoing stem cell transplantation.
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Ueda, Y., Yasoda, A., Yamashita, Y., Kanai, Y., Hirota, K., Yamauchi, I., Kondo, E., Sakane, Y., Yamanaka, S., Nakao, K., Fujii, T., Inagaki, N., 2016. Bone 92, 157–167.
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Wang, W., Song, M.H., Miura, K., Fujiwara, M., Nawa, N., Ohata, Y., Kitaoka, T., Kubota, T., Namba, N., Jin, D.K., Kim, O.H., Ozono, K., Cho, T.-J., 2016. Am J Med Genet A 170A, 426–434.
PMID:26567084 - Estimation of the renin-angiotensin-aldosterone system, water and electrolyte imbalance and endothelial function in newborns of women with chronic hypertension.
Chistiakova, G.N., Gazieva, I.A., Rmizova, I.I., 2015. Fiziol Cheloveka 41, 124–129
PMID:25857186 - Serial Evaluation of Abdominal Fluid and Serum Amino-terminal pro-C-type Natriuretic Peptide in Dogs with Septic Peritonitis.
Guieu, L.V.S., Bersenas, A.M.E., Holowaychuk, M.K., Brisson, B.A., Weese, J.S., 2015. Journal of Veterinary Internal Medicine 29, 1300–1306.
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Kaiser, R., Grotemeyer, K., Lepper, P., Stokes, C., Bals, R., Wilkens, H., 2015. Respiratory Medicine 109, 1213–1223.
- Skeletal overgrowth syndrome caused by overexpression of C-type natriuretic peptide in a girl with balanced chromosomal translocation, t(1;2)(q41;q37.1).
Ko, J.M., Bae, J.-S., Choi, J.S., Miura, K., Lee, H.R., Kim, O.-H., Kim, N.K.D., Oh, S.K., Ozono, K., Lee, C.-K., Choi, I.H., Park, W.-Y., Cho, T.-J., 2015. Am J Med Genet A 167A, 1033–1038.
PMID:25728306 - The alteration of NTproCNP plasma levels following anaerobic exercise in physically active young men.
Temür, H.A., Vardar, S.A., Demir, M., Palabıyık, O., Karaca, A., Guksu, Z., Ortanca, A., Süt, N., 2015. Anatol J Cardiol 15, 97–102.
PMID:25252292; PMCID: PMC5337023 - NT-pro CNP Level Estimation; Its Experimental and Clinical Relevance.
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- The concentrations of the inflammatory markers the amino-terminal portion of C-type pronatriuretic peptide and procalcitonin in canine babesiosis caused by Babesia canis.
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Miura, K., Kim, O.-H., Lee, H.R., Namba, N., Michigami, T., Yoo, W.J., Choi, I.H., Ozono, K., Cho, T.-J., 2014. American Journal of Medical Genetics Part A 164, 156–163.
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Cappellin, E., Gatti, R., Antonelli, G., Soldà, G., Ragazzi, E., Palo, E.F.D., Spinella, P., 2013. Journal of Cardiovascular Medicine 14, 308.
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Kuehnl, A., Pelisek, J., Bruckmeier, M., Safi, W., Eckstein, H.-H., 2013. Journal of Negative Results in BioMedicine 12, 7.
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Cabiati, M., Caruso, R., Caselli, C., Frigerio, M., Prescimone, T., Parodi, O., Giannessi, D., Del Ry, S., 2012. Peptides 36, 192–198.
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Czech‐Kowalska, J., Pludowski, P., Dobrzanska, A., Kryskiewicz, E., Karczmarewicz, E., Gruszfeld, D., Pleskaczynska, A., Golkowska, M., 2012. Bone 51, 781–786.
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Koch, A., Zimmermann, H.W., Baeck, C., Schneider, C., Yagmur, E., Trautwein, C., Tacke, F., 2012. Clinical Biochemistry 45, 429–435.
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Miura, K., Namba, N., Fujiwara, M., Ohata, Y., Ishida, H., Kitaoka, T., Kubota, T., Hirai, H., Higuchi, C., Tsumaki, N., Yoshikawa, H., Sakai, N., Michigami, T., Ozono, K., 2012. PLOS ONE 7, e42180.
- Amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) predicts height velocity in healthy children.
Olney, R.C., Permuy, J.W., Prickett, T.C.R., Han, J.C., Espiner, E.A., 2012. Clin Endocrinol (Oxf) 77, 416–422.
PMID:22435455; PMCID: PMC3466812 - Comparison of NT-proCNP and CNP plasma levels in heart failure, diabetes and cirrhosis patients.
Del Ry, S., Cabiati, M., Stefano, T., Catapano, G., Caselli, C., Prescimone, T., Passino, C., Emdin, M., Giannessi, D., 2011. Regul Pept 166, 15–20.
PMID: 20800621 - Prognostic value of circulating amino-terminal pro-C-type natriuretic peptide in critically ill patients.
Koch, A., Voigt, S., Sanson, E., Dückers, H., Horn, A., Zimmermann, H.W., Trautwein, C., Tacke, F., 2011. Critical Care 15, R45.
- Measurement of amino-terminal propeptide of C-type natriuretic peptide in patients with idiopathic short stature or isolated growth hormone deficiency.
Xiao, Y., Dong, Z., Lu, W., Wang, X., Sun, W., Wang, D., Ni, J., Chen, F., Wang, J., Wang, W., 2011. J. Pediatr Endocrinol Metab 24, 989–994
PMID:22308853 - N-Terminal Pro C-Type Natriuretic Peptide Relation With Prolactin in the Elderly.
Cappellin, E., Spinella, P., Antonelli, G., Gatti, R., Soldà, G., De Palo, E.F., 2010. The Endocrinologist 20, 185–189.
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Olewicz-Gawlik, A., Danczak-Pazdrowska, A., Klama, K., Silny, W., Prokop, J., Mackiewicz, S., Grala, P., Hrycaj, P., 2010. Connect. Tissue Res. 51, 83–87.
PMID:20001845 - Natriuretic pro-peptides in idiopathic intracranial hypertension.
Skau, M., Goetze, J.P., Rehfeld, J.F., Jensen, R., 2010. Regulatory Peptides 164, 71–77.
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Nielsen, S.J., Iversen, P., Rehfeld, J.F., Jensen, H.L., Goetze, J.P., 2009. APMIS 117, 60–67.
PMID:19161538 - Amino-Terminal Pro-C-Type Natriuretic Peptide is Associated with the Presence, Severity, and Duration of Vasculogenic Erectile Dysfunction.
Vlachopoulos, C., Ioakeimidis, N., Terentes-Printzios, D., Rokkas, K., Aznaouridis, K., Baou, K., Bratsas, A., Fassoulakis, C., Stefanadis, C., 2009. European Urology 56, 552–558.
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Dietmann, A., Lackner, P., Helbok, R., Spora, K., Issifou, S., Lell, B., Reindl, M., Kremsner, P.G., Schmutzhard, E., 2008. Malaria Journal 7, 253.
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Hammerer-Lercher, A., Sommer, R., Mair, J., Tulzer, G., Lechner, E., Hawa, G., Maitzen, S., Woloszczuk, W., Puschendorf, B., 2008. Clinica Chimica Acta 391, 118–119.
- C-type natriuretic peptide concentrations in the plasma and cerebrospinal fluid of patients with subarachnoid hemorrhage.
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PMID:30844819