Salivary IgA is a weak stress marker.

Several studies support the hypothesis that psychological stress may negatively affect immunocompetence. The present study sought to determine whether a relationship can be established between a measure of psychological state of stress and level of immunoglobulin of the A class (IgA) in saliva. To this end, 44 dentistry students were tested on four occasions; two occasions were stress inductive (examination situation), and two occasions were free of any academic stressor. At each session, the participants were asked to fill out the stress rating instrument, and unstimulated whole saliva samples were obtained. Salivary IgA was measured by a microplate Enzyme Linked Immunosorbent Assay (ELISA). A significant difference in the level of salivary IgA was observed only for the most polarized contrast, ie, between final exam and end of summer vacation (p less than .01). A weak negative correlation between the level of salivary IgA and the stress rating was observed (r = -0.25) only at the final exam. Our results suggest that assaying immunoglobulin A in saliva to measure stress may not be as useful in psychophysiological research as expected.