Pilot study comparing the salivary cationic protein concentrations in healthy adults and AIDS patients : correlation with antifungal activity

This investigation compared the salivary cationic protein concentrations of 12 healthy adult controls with those of 12 hospitalized patients with AIDS. Salivas were quantified by capillary electrophoresis using purified cationic protein standards. In parotid saliva, histidine-rich polypeptides (HRPs) 1-6, histatin 6, and lysozyme concentrations were determined. In addition to these eight cationic proteins, submandibular-sublingual saliva was also quantified for histatin 2 and the histatin 2 degradation product. When comparisons were made on the basis of individual proteins, the HRP-histatin concentrations in the AIDS patients showed either statistically significant decreases or a decreasing trend compared with healthy adult controls. When HRP-histatin concentrations were summed for each patient, there were statistically significant differences between the healthy adult controls and the individuals with AIDS in both parotid and submandibular-sublingual salivas. Closer examination revealed that some individuals with AIDS had HRP-histatin concentrations that fell within the normal range of the healthy adult controls. For these individuals, lower than expected salivary antifungal values were obtained. Either decreasing histidine-rich protein concentrations and/or an inability of these proteins in saliva to interact with Candida albicans may contribute to the defective salivary antifungal activity seen in AIDS patients.