Dynamics of stress-related decrease of salivary immunoglobulin A (sIgA): relationship to symptoms of the common cold and studying behavior.

The dynamics of stress-related decrease of salivary Immunoglobulin A (sIgA) were examined with respect to whether an increase of upper respiratory tract (URT) symptoms can be observed concurrently with or subsequent to sIgA alterations and whether one can use students' studying behavior during academic examinations to predict changes in sIgA. From a 2-part medical examination of 42 students, daily measures of sIgA were obtained, and symptoms of URT infections and studying behavior were determined by means of questionnaires. Assessment periods began 7 days before each part of the academic examination began and lasted until the 6th day afterward. A control group of 24 medical students who were not undergoing examinations also responded to all questionnaires. A progressive suppression of sIgA, outlasting the examination period by more than 6 days, was observed. Time spent studying explained a significant proportion in sIgA variation. However, no relationship between sIgA and URT symptoms was observed, nor did students who took academic examinations differ from untested controls in symptom rates.