Salivary immunoglobulin A levels in normal subjects, tobacco smokers, and patients with minor aphthous ulceration.

There seems to be no relationship between time of day and SlgA concentration in pooled unstimulated saliva. Such concentrations are more accurately expressed as a range of normal. A selected group of tobacco smokers showed a decrease in SlgA concentrations when compared with a matched control group, and a group of patients with minor aphthous ulcerations showed no deviation from the control range. The significance of the decrease in SlgA concentrations in chronic tobacco smokers is discussed in the light of this being due to an immunosuppressive effect of the combustion products of tobacco and the possibility of the incidence of intraoral neoplastic disease being increased in tobacco smokers by this effect.