Investigation of buccal mucosa salivary protein collection methods from salivary proteins and evaluation by proteomic analysis with the goal of detecting the development of aspiration pneumonia

Abstract

　Aspiration pneumonia (AP), one of the major causes of death in the older people, does not accompany typical symptoms of pneumonia in the early stages of onset. This characteristic makes AP difficult to detect and treat early. We have been engaging in development of biomarkers for the detection and focusing on salivary proteins, which contains various immune-related proteins. Because spitting out saliva is often difficult for older people, in this present study we report the optimized method to collect saliva proteins from buccal mucosa. First, we compared types of oral care products, optimized scrubbing method and number of times to scrub, and tested the effects of moisturizer. Our results showed that the best method was to use a sponge brush and rub the buccal mucosa from the back to the front 10 times. Next, we examined whether our method could collect the immune-related saliva proteins by shotgun proteomics using LC-MS/MS. Of the 2,758 salivary proteins registered in the database, 1,732 were detected including α-amylase and IgA, showing that this method is applicable.