The response of salivary protein levels and S-IgA to an academic examination are associated with daily stress

Acute real-life stress is capable of altering several aspects of the oral defense system, such as the salivary levels of S-IgA, α-amylase, total protein, and the capacity of saliva to aggregate streptococcal bacteria. In this study, we further explored whether these acute changes are influenced by the chronic stress of everyday problems. We collected unstimulated saliva from 28 dental students, before an academic examination and two and six weeks later in a period of low study pressure. Daily hassles experienced over the past two months were measured by a checklist. The results demonstrate that stress-mediated increases in S-IgA output, α-amylase activity, and total protein concentration were consistently and positively correlated with both the number and intensity of experienced daily hassles. These findings add to the results of recent studies indicating that the stress of everyday life can affect psychobiologic functioning, resulting in an altered physiological response to acute stress. This mechanism may, in part, account for the observed relationship of both physiological reactivity and daily hassles with susceptibility to infectious disease. We further argue for the incorporation of parameters that monitor the functioning of non-immunological defense systems, in addition to immunological parameters, when studying possible mediators of the relationship between stress and infectious disease.