The use of salivary proteomics to monitor disease activity in periodontitis

Stewart, K.W.1, Haigh, B.J.2, Whelan, J.R.K.3, Barnett, M.2, Smolenski, G.A.2, & Wheeler, T.T.2
1 School of Science & Primary Industries, Waikato Institute of Technology, Hamilton, New Zealand; 2 Dairy Science & Technology Group, AgResearch Ruakura, New Zealand, 3Whelan and Associates, Auckland, New Zealand.

Periodontitis is a common, bacterially-induced, inflammatory disease of the support tissues of the teeth. Prolonged inflammation causes tissue destruction which is often episodic and difficult to detect and monitor. A non-invasive method for monitoring the severity of this condition would be an asset in informing its treatment. This study used quantitative proteomics (2D SDS PAGE) to screen for potential biomarkers in whole saliva. A proteomic profile of samples from 9 individuals with severe periodontitis was compared before and after periodontal treatment. A comparison of 128 protein spots across all saliva samples identified 15 with altered abundance. The predominant alteration observed was an increase in the abundance of three S100 proteins, which are involved in the regulation of inflammation. Of the remaining proteins with altered abundance that were able to be identified, haptoglobin, prolactin inducible protein and parotid secretory protein have previously been associated with host defence. These results highlight the predominant involvement of S100 proteins in the host response during periodontitis, identify host defence components which have not previously been linked to this disease and suggest new potential biomarkers for monitoring disease activity in periodontitis.