Brief uncontrollable stress and psychological parameters influence human plasma concentrations of IgM and complement component C3.

Thirty-eight men participated in a study of immunological, hormonal, and psychological parameters before and after acute stress situations. A brief but acute stress was repeated daily for 4 days. This exposure caused the plasma levels of IgM and C3 to increase from Basal Day to Experimental Day 4. Significant correlations between endocrine and immunological parameters, and also between psychological measures and immunological parameters, were found. Use of psychological defense was related both to endocrine and immunological changes. The authors concluded that psychological stress may influence immunological functions both indirectly, by hormonal changes, and directly, by nervous regulation during brief but acute stress periods.