The shape of stress: the use of frequent sampling to measure temporal variation in S-IgA levels during acute stress

Previous studies have indicated that statistically significant increases in Secretory immunoglobulin A (S-IgA) can be achieved in as little as 5 min as a result of mental stress. However, the temporal resolution of these changes is low and therefore the rate and pattern of changes during the stress task and during subsequent recovery is unclear. A within-subjects design was used to examine levels of S-IgA before, during and after a short (8 min) mental stress task. S-IgA was measured from saliva samples obtained every 2 min during the entire 30-min session. Significant increases in S-IgA concentration were observed as early as the task instruction period, with additional increases during the stress task itself. The data also show a rapid recovery of S-IgA, with a return to baseline levels within 6 min. Results suggest that S-IgA changes can occur very rapidly and that the observed increases are short-lived. Copyright (C) 2007 John Wiley & Sons, Ltd.