The effect of parotid salivary flow rate on the levels of salivary antimicrobial proteins in patients with Sjögren's syndrome

Objective: The purpose of this study was to examine the effect of salivary flow rate on the levels of antimicrobial salivary proteins in 24 patients with Sjögren's syndrome and 22 age- and race-matched healthy control subjects. Method and materials: Parameters examined included stimulated salivary flow rate, total salivary protein, lactoferrin, lysozyme, amylase, and secretory immunoglobulin A. Results: The mean total salivary protein and the mean salivary amylase were significantly greater in patients than in controls. However, no significant difference was observed in the mean stimulated salivary flow rates or the levels of lactoferrin, lysozyme, or secretory immunoglobulin A of patients and controls. To examine the effect of salivary flow rate on the levels of salivary antimicrobial protein, the levels of these proteins in patients with salivary flow rate of ≤ 0.3 mL/min per gland were compared to those in healthy controls with salivary flow rate ≥0.4 ml/min per gland. Analyses showed the levels of lactoferrin to be significantly higher among patients than among controls. Conclusion: The levels of salivary amylase and lactoferrin may be influenced by the levels of salivary output in patients with Sjögren's syndrome. The relationship between salivary flow rate and the levels of amylase and lactoferrin is not clear at the present time.