The effect of acute ethanol intoxication on salivary proteins of innate and adaptive immunity.

BACKGROUND

Human salivary proteins: peroxidase, lysozyme, lactoferrin, and IgA, participate in the protection of oral tissues, as well as upper digestive and respiratory tracts, against a number of microbial pathogens. In the current study, we investigated the effect of acute consumption of a large dose of ethanol on representative human salivary proteins of the innate and adaptive immune systems.

METHODS

Eight healthy male volunteers drank an average of 2.0 g (1.4 to 2.5 g/kg) body weight of ethanol, in the form of vodka, in the 6-hour period. Samples of resting whole saliva were collected 12 hours before, then 36 and 108 hours after, the alcohol consumption. The levels of total protein, immunoglobulin A, lysozyme and lactoferrin as well as peroxidase activity were determined in saliva.

RESULTS

At 36 hours after alcohol consumption, salivary protein and lysozyme concentrations as well as peroxidase activity were significantly decreased (p = 0.002, p = 0.043, and p = 0.003, respectively), in comparison to the values obtained at 12 hours before drinking. Between 36 and 108 hours after alcohol consumption, the salivary protein and lysozyme concentrations, as well as peroxidase activity showed a tendency to increase, although at 108 hours after the drinking session, the concentration of protein and peroxidase activity were still significantly lower than before drinking. There was no significant change in the level of lactoferrin, after the drinking session. The salivary concentration of IgA tended to increase at 36 hours after alcohol consumption, and at 108 hours it was significantly higher (p = 0.028), when compared to IgA concentration in the saliva collected before drinking (from 8% to 26% and 32% of total protein content, respectively).

CONCLUSION

Our report is the first to show that acute ingestion of relatively large, yet tolerable dose of alcohol, significantly disturbs salivary antimicrobial defense system. Reduced lysozyme level and decreased peroxidase activity may contribute to increased susceptibility to infections, when acute alcohol intake coincides with exposure to pathogens.