Endogenous vascular synthesis of B-type and C-type natriuretic peptides in the rainbow trout

Analytical barriers in clinical B-type natriuretic peptide measurement and the promising analytical methods based on mass spectrometry technology

B-type natriuretic peptide (BNP) is a circulating biomarker that is mainly applied in heart failure (HF) diagnosis and to monitor disease progression. Because some identical amino acid sequences occur in the precursor and metabolites of BNP, undesirable cross-reactions are common in immunoassays. This review first summarizes current analytical methods, such as immunoassay- and mass spectrometry (MS)-based approaches, including the accuracy of measurement and the inconsistency of the results. Second, the review presents some promising approaches to resolve the current barriers in clinical BNP measurement, such as how to decrease cross-reactions and increase the measurement consistency. Specific approaches include research on novel BNP assays with higher-specificity chemical antibodies, the development of International System of Units (SI)-traceable reference materials, and the development of structure characterization methods based on state-of-the-art ambient and ion mobility MS technologies. The factors that could affect MS analysis are also discussed, such as biological sample cleanup and peptide ionization efficiency. The purpose of this review is to explore and identify the main problems in BNP clinical measurement and to present three types of approaches to resolve these problems, namely, materials, methods and instruments. Although novel approaches are proposed here, in practice, it is worth noting that the BNP-related peptides including unprocessed proBNP were all measured in clinical BNP assays. Therefore, approaches that aimed to measure a specific BNP or proBNP might be an effective way for the standardization of a particular BNP form measurement, instead of the standardization of “total” immunoreactive BNP assays in clinical at present.

NT-proBNP is associated with SYNTAX score and aortic distensibility in patients with stable CAD

OBJECTIVE

A high N-terminal pro-brain natriuretic peptide (NT-proBNP) level provides significant prognostic information on patients with coronary artery disease (CAD). It is unclear whether aortic distensibility (AD), which reflects the aortic stiffness, and the extent and complexity of CAD, assessed with the SYNTAX score (SS), affect the secretion of NT-proBNP in stable CAD. We aimed to investigate the relationship between NT-proBNP levels and AD as well as with the extent and complexity of CAD in stable CAD patients.

METHODS

The study included 411 patients with stable CAD (mean age = 61.7 ± 9.9 years, male/female = 247/164). The patients were divided into two groups according to the median NT-proBNP value (NT-proBNPlow group < 114 pg/ml and NT-proBNPhigh group ≥ 114 pg/ml). AD was calculated from the echocardiographically derived ascending aorta diameters and hemodynamic pressure measurements. Coronary angiography was performed and SS was determined in all patients. NT-proBNP and other biochemical markers were measured in all subjects.

RESULTS

The AD and ejection fraction values of the NT-proBNPhigh group were lower and their SS levels were higher compared with those from the NT-proBNPlow group (p < 0.05, for all). The NT-proBNP level was independently associated with AD (β = -0.378, p < 0.001), SS (β = 0.262, p < 0.001), and ejection fraction (β = - 0.295, p < 0.001) on multiple linear regression analysis.

CONCLUSION

NT-proBNP was independently associated with an impaired elastic property of the aorta and with the extent and complexity of CAD as well as with left ventricular systolic dysfunction.

N-terminal pro-brain natriuretic peptide levels and aortic diameters

BACKGROUND

Women with X-chromosome monosomy or Turner syndrome (TS) are at increased risk for aortic dilation and dissection. To better understand the pathology and develop tools to monitor the risk of aortic disease, we investigated N-terminal pro-brain natriuretic peptide (BNP) (NT-proBNP) levels in women with TS and healthy female controls.

METHODS

We evaluated NT-proBNP levels in women with karyotype-proven TS and healthy female volunteers in relation to ascending aortic diameter and descending aortic diameter measured by cardiovascular magnetic resonance imaging.

RESULTS

The NT-proBNP levels were strongly and positively correlated with ascending aortic diameter and descending aortic diameter in both cohorts. The TS group (n = 114, age 37.4 ± 12 yr) had greater body surface area-indexed aortic diameters and higher NT-proBNP levels than the control group (n = 27, age 46.4 ± 11 years): 88.3 ± 62.7 versus 53.5 ± 35 pg/mL, P = .0003. Within the TS group, NT-proBNP levels were higher in those with dilated ascending aorta (n = 42, 112.4 ± 75.7 pg/mL) compared with those with normal aortic dimensions (n = 72, 74.2 ± 49 pg/mL, P = .0014). Abnormally high NT-pro BNP levels were seen in 3 of 4 TS women who presented with previously undetected aortic aneurysm and/or dissection.

CONCLUSIONS

The NT-proBNP levels are positively associated with aortic diameters in women with and without TS, suggesting a role for BNP in arterial wall homeostasis. Further study is necessary to determine whether NT-proBNP measurement may be used to monitor aortic diameter and/or detect aortic pathology in individuals at risk for aortic disease.