Monitoring Heart Failure – SALIVA ANALYSIS of Cardiac Marker NT-proBNP
NT-proBNP saliva analysis for heart failure assessment. Monitoring Heart Failure – SALIVA ANALYSIS of Cardiac Marker NT-proBNP
The cardiac marker NT-pro-brain natriuretic peptide (NT-proBNP) is considered as the gold standard biomarker for the diagnosis and monitoring of heart failure (HF). It is tested in blood samples by immunochemical methods. Saliva analysis has gained importance as an alternative non-invasive and efficient tool for the diagnosis of several diseases. A recent report investigated the use of the Biomedica ELISA assay for the determination of NT-proBNP in saliva samples collected from HF patients. First results highlight the potential role of saliva analysis for HF assessment through NT-proBNP monitoring.
Learn more: Determination and stability of N-terminal pro-brain natriuretic peptide in saliva samples for monitoring heart failure. Link to full text.
Bellagambi FG, Petersen C, Salvo P, Ghimenti S, Franzini M, Biagini D, Hangouët M, Trivella MG, Di Francesco F, Paolicchi A, Errachid A, Fuoco R, Lomonaco T. Sci Rep. 2021. 22;11(1):13088. doi: 10.1038/s41598-021-92488-2. PMID: 34158583.
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Heart failure (HF) is the main cause of mortality worldwide, particularly in the elderly. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the gold standard biomarker for HF diagnosis and therapy monitoring. It is determined in blood samples by the immunochemical methods generally adopted by most laboratories. Saliva analysis is a powerful tool for clinical applications, mainly due to its non-invasive and less risky sampling. This study describes a validated analytical procedure for NT-proBNP determination in saliva samples using a commercial Enzyme-Linked Immuno-Sorbent Assay. Linearity, matrix effect, sensitivity, recovery and assay-precision were evaluated. The analytical approach showed a linear behaviour of the signal throughout the concentrations tested, with a minimum detectable dose of 1 pg/mL, a satisfactory NT-proBNP recovery (95–110%), and acceptable precision (coefficient of variation ≤ 10%). Short-term (3 weeks) and long-term (5 months) stability of NT-proBNP in saliva samples under the storage conditions most frequently used in clinical laboratories (4, − 20, and − 80 °C) was also investigated and showed that the optimal storage conditions were at − 20 °C for up to 2.5 months. Finally, the method was tested for the determination of NT-proBNP in saliva samples collected from ten hospitalized acute HF patients. Preliminary results indicate a decrease in NT-proBNP in saliva from admission to discharge, thus suggesting that this procedure is an effective saliva-based point-of-care device for HF monitoring.
NT-ProBNP levels in saliva and its clinical relevance to heart failure. Foo JY, Wan Y, Kostner K, Arivalagan A, Atherton J, Cooper-White J, Dimeski G, Punyadeera C. PLoS One. 2012;7(10):e48452. doi: 10.1371/journal.pone.0048452. PMID: 23119023. Full text link
Abstract: Current blood based diagnostic assays to detect heart failure (HF) have large intra-individual and inter-individual variations which have made it difficult to determine whether the changes in the analyte levels reflect an actual change in disease activity. Human saliva mirrors the body’s health and well being and ∼20% of proteins that are present in blood are also found in saliva. Saliva has numerous advantages over blood as a diagnostic fluid which allows for a non-invasive, simple, and safe sample collection. The aim of our study was to develop an immunoassay to detect NT-proBNP in saliva and to determine if there is a correlation with blood levels. Methods: Saliva samples were collected from healthy volunteers (n = 40) who had no underlying heart conditions and HF patients (n = 45) at rest. Samples were stored at -80°C until analysis. A customised homogeneous sandwich AlphaLISA((R)) immunoassay was used to quantify NT-proBNP levels in saliva. Results: Our NT-proBNP immunoassay was validated against a commercial Roche assay on plasma samples collected from HF patients (n = 37) and the correlation was r(2) = 0.78 (p<0.01, y = 1.705× +1910.8). The median salivary NT-proBNP levels in the healthy and HF participants were <16 pg/mL and 76.8 pg/mL, respectively. The salivary NT-proBNP immunoassay showed a clinical sensitivity of 82.2% and specificity of 100%, positive predictive value of 100% and negative predictive value of 83.3%, with an overall diagnostic accuracy of 90.6%. Conclusion: We have firstly demonstrated that NT-proBNP can be detected in saliva and that the levels were higher in heart failure patients compared with healthy control subjects. Further studies will be needed to demonstrate the clinical relevance of salivary NT-proBNP in unselected, previously undiagnosed populations.
Saliva diagnostics – Current views and directions. Exp Biol Med (Maywood). 2017 Mar;242(5):459-472. doi: 10.1177/1535370216681550. PMID: 27903834; PMCID: PMC5367650. Full text link
Abstract: In this review, we provide an update on the current and future applications of saliva for diagnostic purposes. There are many advantages of using saliva as a biofluid. Its collection is fast, easy, inexpensive, and non-invasive. In addition, saliva, as a “mirror of the body,” can reflect the physiological and pathological state of the body. Therefore, it serves as a diagnostic and monitoring tool in many fields of science such as medicine, dentistry, and pharmacotherapy. Introduced in 2008, the term “Salivaomics” aimed to highlight the rapid development of knowledge about various “omics” constituents of saliva, including: proteome, transcriptome, micro-RNA, metabolome, and microbiome. In the last few years, researchers have developed new technologies and validated a wide range of salivary biomarkers that will soon make the use of saliva a clinical reality. However, a great need still exists for convenient and accurate point-of-care devices that can serve as a non-invasive diagnostic tool. In addition, there is an urgent need to decipher the scientific rationale and mechanisms that convey systemic diseases to saliva. Another promising technology called liquid biopsy enables detection of circulating tumor cells (CTCs) and fragments of tumor DNA in saliva, thus enabling non-invasive early detection of various cancers. The newly developed technology-electric field-induced release and measurement (EFIRM) provides near perfect detection of actionable mutations in lung cancer patients. These recent advances widened the salivary diagnostic approach from the oral cavity to the whole physiological system, and thus point towards a promising future of salivary diagnostics for personalized individual medicine applications including clinical decisions and post-treatment outcome predictions. Impact statement The purpose of this mini-review is to make an update about the present and future applications of saliva as a diagnostic biofluid in many fields of science such as dentistry, medicine and pharmacotherapy. Using saliva as a fluid for diagnostic purposes would be a huge breakthrough for both patients and healthcare providers since saliva collection is easy, non-invasive and inexpensive. We will go through the current main diagnostic applications of saliva, and provide a highlight on the emerging, newly developing technologies and tools for cancer screening, detection and monitoring.