Parotid salivary S-IgA antibodies during experimental gingivitis in smokers and non-smokers

Persons who smoke display a less pronounced increase of gingival bleeding in the experimental gingivitis model as compared with non-smokers. The aim of the present study was to investigate whether this could partly be explained by differences in levels of parotid total secretory IgA (S-IgA) or parotid S-IgA reactive with selected oral microorganisms. Parotid saliva samples were obtained from 11 smoking and 14 non-smoking volunteers, at baseline, after 5 and 14 days of full mouth experimental gingivitis. Output levels of total S-IgA and of specific S-IgA reactive with cell extracts from Actinobacillus actinomycetemcomitans, Actinomyces naeslundii, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Peptostreptococcus micros, Streptococcus gordonii and Streptococcus mutans were determined in the samples by means of ELISA. Smokers and non-smokers were found to have similar output levels (microg/min) of total S-IgA, and the values did not significantly change during the experimental gingivitis trial. Parotid salivary outputs (units/min) of the bacteria-specific S-IgA at baseline and at days 5 and 14, were not different between smokers and non-smokers; no changes were observed during the experimental gingivitis trial. The present observations indicate that total S-IgA and bacteria-specific S-IgA in saliva are not main factors that can explain the less pronounced increase of gingival bleeding in the experimental gingivitis model in smokers as compared with non-smokers.