Effects of tobacco smoking on salivary immunoglobulin levels in immunodeficiency

Salivary immunoglobulins and albumin were analysed in smoking and non-smoki ng immunocompetent and immunodeficient individuals. Stimulated and unstimul ated saliva were compared as between individuals with selective immunoglobu lin A deficiency (IgAd), common variable immunodeficiency (CVI) and immunoc ompetent individuals. Immunocompetent smokers showed increased levels of sI gA in unstimulated saliva, when compared with non-smoking immunocompetent i ndividuals. In stimulated saliva, the immunocompetent smokers showed decrea sed levels of IgG and IgM. IgAd smokers showed decreased levels of albumin in unstimulated saliva, when compared with non-smoking IgAd individuals. Th e non-smoking individuals with IgAd showed increased levels of IgM in both unstimulated and stimulated saliva, when compared with immunocompetent smok ers. The non-smoking CVI individuals showed decreased levels of IgG, IgA an d IgM in unstimulated and stimulated saliva, as expected, when compared wit h the same group of immunocompetent individuals. The decreased levels of al bumin in unstimulated saliva in IgAd smokers and comparable to that of the IgG non-smoking IgAd individuals support the observation of locally produce d immunoglobulins that protect the oral mucosa. Instead of sIgA, non-smokin g immunodeficient individuals with IgAd compensate with increased IgM level s in stimulated saliva. The increased levels of sIgA in unstimulated saliva in immunocompetent smokers may be a reflection of the protection of the or al mucosa.