Tobon-Arroyave SI, et al. - In this cross-sectional case-control study, the relationship between the salivary concentration of CD9/CD81 exosome-related tetraspanins and the periodontal clinical status was delineated by investigators in saliva samples from 104 periodontitis cases vs 45 healthy controls. In comparison with healthy controls, they observed significantly decreased salivary levels of CD9 and CD81 exosomes in subject with periodontitis. They also found negative significant associations between salivary concentrations of CD9/CD81 exosomes related to clinical measurements. They found a strong/independent association for a reduced salivary concentration of CD81 exosomes regarding disease status in the logistic regression analyses.