Vibrational Spectroscopy Saliva Profiling as Biometric Tool for Disease Diagnostics: A Systematic Literature Review

Abstract

Saliva is a biofluid that can be considered as a “mirror” reflecting our body’s health status. Vibrational spectroscopy, Raman and infrared, can provide a detailed salivary fingerprint that can be used for disease biomarker discovery. We propose a systematic literature review based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to evaluate the potential of vibrational spectroscopy to diagnose oral and general diseases using saliva as a biological specimen. Literature searches were recently conducted in May 2020 through MEDLINE-PubMed and Scopus databases, without date limitation. Finally, over a period of 10 years, 18 publications were included reporting on 10 diseases (three oral and seven general diseases), with very high diagnostic performance rates in terms of sensitivity, specificity, and accuracy. Thirteen articles were related to six different cancers of the following anatomical sites: mouth, nasopharynx, lung, esophagus, stomach, and breast. The other diseases investigated and included in this review were periodontitis, Sjögren’s syndrome, diabetes, and myocardial infarction. Moreover, most articles focused on Raman spectroscopy (n = 16/18) and more specifically surface-enhanced Raman spectroscopy (n = 12/18). Interestingly, vibrational spectroscopy appears promising as a rapid, label-free, and non-invasive diagnostic salivary biometric tool. Furthermore, it could be adapted to investigate subclinical diseases—even if developmental studies are required.

Saliva as a Source of Biomarkers for Periodontitis and Periimplantitis

“…Another promising, rapid, and label-free diagnostic biometric tool in saliva can be provided by vibrational spectroscopy (31). Diagnostic models can eventually be constructed by combining protein and microbial profiles and computing diagnostic powers via areas under the receiver-operating characteristic (ROC) curve (32).…”

COVID-19 salivary Raman fingerprint: innovative approach for the detection of current and past SARS-CoV-2 infections

“…Besides the application in cell and tissue analysis for cancer detection, RS has demonstrated its reliability and promising applicability also in the analysis of complex biological samples like saliva for disease detection and monitoring 15 . The use of saliva as substrate for Raman analysis has demonstrated unparalleled advantages related mainly to the limited sample processing required, the negligible invasiveness of sample collection, coupled to the multitude of molecules and disease biomarkers that can be investigated for clinical purposes 16 . Taking advantage of Surface Enhanced Raman Scattering (SERS), RS challenges current fluorescent based detection methods in terms of both sensitivity and multiplexing ability, detecting multiple components in a mixture, including viruses, in a point-of-care platforms 17 – 19 .…”

Influence of Electronic Cigarettes on Antioxidant Capacity and Nucleotide Metabolites in Saliva

“…Oxidants or reactive oxygen species are also generated by vaporizing e-liquids, which are influenced by the heating element of the electronic cigarette and associated with e-liquid flavor. The aerosol generated by electronic cigarettes might pose an impact on levels of oxidative stress [ 42 ]; however, it has not been proven yet which electronic cigarettes’ factors might be related to oxidative stress generation [ 43 ].…”