Translational and clinical applications of salivary diagnostics

Abstract

There have been significant advances in techniques for the detection of biomarker signals in the oral cavity (e.g., ELISAs for proteins, PCR for RNA and DNA) as well as the engineering and development of microfluidic approaches to make oral-based point-of-care (POC) methods for the diagnosis for both local and systemic conditions a reality. In this section, we focus on three such approaches, namely, periodontal disease management, early markers for systemic diseases, and salivary markers useful for pharmacogenomic studies. Novel approaches using non-invasive, salivary samples and user-friendly devices offer results that are as sensitive and specific as laboratory-based analyses using blood or urine.

Figure 1.

Inter-relationship between changes in the skeleton during bone metabolic diseases such as periodontitis and osteoporosis. The release of oral-fluid- and saliva-based biomarkers of disease may predict both tooth-site and skeletal bone alterations affected by pathogens, bone turnover, or biomechanical influences (Rios and Giannobile, 2010).

Figure 2.

Multi-analyte detection of salivary biomarkers predicts periodontal disease status. Receiver operator curves (ROC) of combinatorial permutations of salivary biomarkers [matrix metalloproteinase-8 (MMP-8), C-telopeptide (ICTP), osteoprotegerin (OPG)] coupled with biofilm subgingival pathogens such as Treponema denticola measured by quantitative PCR. AUC = area under the curve; OR = odds ratio; numbers in brackets are 95% confidence intervals. From Ramseier et al. (2009).

Figure 3.

Schematic illustration showing the main elements of the programmable bio-nano-chip system (PBNC). The universal detection system completes both cell-based (top image sequence, a i to c i) as well as soluble analyte tests (bottom image sequence, a ii to c ii).