Differential effects of active and passive coping on secretory immunity

This study examined the acute immunological effects of two laboratory stressors, expected to evoke distinct patterns of cardiac autonomic activity; namely an "active coping" time-paced memory test, and a "passive coping" stressful video showing surgical operations. We measured salivary S-IgA, IgA-subclasses (IgA1, IgA2), and secretory component (SC). SC is responsible for the transport of S-IgA across the epithelium, and thus a rate-determining step in S-IgA secretion. Thirty-two male undergraduates were subjected to both stressors and a control video (a didactic television program). The memory test induced a typical "fight-flight" response, characterized by increases in heart rate and blood pressure in association with a decrease in cardiac preejection period (PEP) and vagal tone. The surgical video produced a "conservation-withdrawal"-like response, characterized by an enhanced vagal tone, a decrease in heart rate, and a moderate sympathetic coactivation (as indicated by a shortened PEP and an increased systolic pressure). The memory test induced an increase in the concentration and, to a lesser extent, in the output of S-IgA, IgA1, and SC. The output of IgA2 was not significantly affected. For the surgical video, a different pattern emerged: During stressor exposure S-IgA remained unaffected, against the background of a small increase in SC output. However, 10 min after the surgical video S-IgA levels had decreased. This decrease in S-IgA was paralleled by a decrease in IgA1, but not IgA2. We conclude that acute stress can have both enhancing and suppressive effects on secretory immunity, the IgA1 subclass in particular. The mechanisms that underlie these divergent responses may include stressor-specific patterns of autonomic activation.