Secretory IgA in Minor Gland Saliva of Children and Adults

This study determined the concentration of salivary immunoglobulin A (salivary IgA) in saliva from labial and buccal minor glands of children, adolescents, and adults. According to previous studies minor glands produce about 35% of total salivary IgA. Age-dependent increase in whole-saliva salivary IgA concentrations has been studied extensively, but we found no reports comparing minor-gland saliva concentrations of salivary IgA in children, adolescents, and adults. Three age groups donated saliva for analysis: 3-yr-olds (n = 28), 14-yr-olds (n = 27), and 20 to 25-yr-olds (n = 26). Minor-gland saliva was collected on filter paper and unstimulated whole saliva by draining into a tube and salivary IgA concentration was determined by ELISA. Salivary IgA concentration in labial saliva was significantly lower (P < 0.01) among 3-yr-olds (3.7 mg 100 ml-1, SD 3.5) compared to 14-yr-olds (12.6 mg 100ml-1, SD 12.8) and adults (12.8 mg 100ml-1, SD 13.4). The 3-yr-olds also had significantly lower (P < 0.05) whole-saliva salivary IgA values compared to the other age groups (9.0 mg 100ml-1, SD 9.1; 17.9 mg 100ml-1, SD 14.9; and 17.0 mg 100ml-1, SD 9.9, respectively). This increase in salivary IgA concentrations with age might reflect a developing immune response in the growing child