Salivary IgA in minor-gland saliva of children, adolescents, and young adults

Immunoglobulin A (IgA) is the principal immunoglobulin in human saliva and minor salivary glands contribute with approximately 30-35 % of the total salivary IgA in whole saliva. Salivary IgA is considered to be a vital component of the defence of the oral tissues and the concentration seems to increase with age. However, data on the salivary IgA-concentration in minor gland saliva of children, compared to adults, is not available. Objectives: To study the salivary IgA-concentration in minor gland saliva in defined mucosal areas, and in un-stimulated whole saliva, in children in different ages and young adults. Methods: 90 individuals were recruited: 3-year-old children (n = 30), 14-year-old children (n = 30), and young adults (n = 30). Minor gland saliva was collected on labial and buccal mucosa with filter papers and the volume was determined using a Periotron 8000. The whole saliva was collected by draining into a tube. Assessment of the salivary IgA-concentration was carried out in a sandwich ELISA. One-way ANOVA was used testing the differences between the age-groups (at the 0.05 level of significance). Results: The salivary IgA-concentration in labial gland saliva was significantly lower (p