Salivary and serum IgA levels in a geriatric outpatient population.

In two separate studies, specimens of saliva from 57 individuals over the age of 65 years (mean age, 76.7 years) and 37 persons under the age of 40 years (mean age, 28.8 years) were examined for concentrations of IgA as functions of volume, total protein, and electrolyte conductivity; some were also tested for IgG and IgM content. The results show that older persons have higher concentrations of these solutes in their saliva than do younger controls. This suggests that the ability to secrete IgA into saliva does not diminish significantly with aging.