Age-Dependent Changes of Salivary IgA and IgE Levels in Healthy Subjects

Abstract

Background: The secretory immunoglobulin A (IgA) is the first line of defense againstpathogens that invade mucosal surfaces. It has been reported that the immune system exhibits profound age-related changes. The aim of this study was to investigate the age-dependent changes of salivary IgA and IgE levels among healthy subjects.

Methods: Saliva samples were collected from 203 healthy individuals (aged 1-70 years). The salivary IgA and IgE concentrations were measured by use of ELISA technique and analyzed using the Mann-Whitney U, Kruskal-Wallis and Chi-Square tests.

Results: The mean salivary IgA levels were 42.67 μg/ml  at age 1-10 years, 82.44 μg/ml at age 11-20 years, 93.5 μg/ml  at age 21-30 years, 97.58 μg/ml  at age 31-40 years, 106.45 μg/ml  at age 41-50 years, 113.47 μg/ml  at age 51-60 years and 92.95 μg/ml at age 61-70 years. There was significant difference among mean salivary IgA levels of different age groups (P < 0.001). The frequency of subjects with detectable concentrations of salivary IgE increased with increasing age up to 40 years and thereafter decreased. There was also significant difference among the mean salivary IgE levels of different age groups (P < 0.001). In adults, the mean salivary levels of IgA and IgE were significantly higher than those observed in children (P < 0.0001 and P < 0.002, respectively).

Conclusion: These results showed that the salivary IgA and IgE levels exhibit age-related changes. Oral immunization may be considered to improve oral immunity when the salivary concentrations of IgA begin to decrease during lifetime.

Keywords: Adult, immunoglobulin A, immunoglobulin E, saliva.