Age-related changes of salivary IgA among healthy subjects

Abstract

Introduction: The major immunoglobulin present in mucosal secretions (e.g. saliva) is secretory immunoglobulin A (IgA). The potential functions of this secretory IgA include prevention of microbial attachment to surfaces by agglutination, blockage of receptor-mediated attachment, and altering surface hydrophobicity. IgA in saliva is detected early in life as the mucosal immune system develops and the oral cavity is exposed to microbes that make up the normal ecology, as well as to potential pathogens. Lower concentration of IgA in saliva is associated with increased risk for periodontal disease and caries. The secretory IgA is the first line of defense against pathogens that invade the mucosal surfaces. The immune system exhibits profound changes with age and this fact has been well documented. Aims and Objectives: To investigate and re-confirm that salivary IgA concentration undergoes changes with advancing age, and further, to find if there is any probable difference in salivary IgA levels between men and women. Materials and Methods: Saliva samples were taken from 120 healthy subjects aged 1-60 years who were divided into the following age groups: 1-10 years, 11-20 years, 21-30 years, 31-40 years, 41-50 years, and 51-60 years. The salivary IgA concentrations were measured by use of single radial immune diffusion technique and analyzed using the paired and unpaired Student's t-test, and coefficient test as appropriate, and P values of less than 0.5 were considered significant. Results: The mean salivary IgA levels showed significant changes in each decade of the subjects selected. The mean salivary IgA levels were significantly higher in adults than those observed in children. Conclusion: These results showed that the salivary IgA levels exhibit age-related changes.