Effect of stress and other biopsychosocial factors on primary antibody response

There is growing evidence that life stress is associated with altered cellular immune function, but only a few studies have examined the effect of stress on humoral immune response. We immunized 89 healthy women (18-24 years) with a novel antigen, keyhole limpet hemocyanin (KLH), to study the impact of stressful events and psychosocial and biologic factors on primary antibody response to immunization. Antibodies to KLH were measured preimmunization and 3 and 8 weeks after immunization. Previously validated scales were used to measure (1) recent major stress (both "good" and "bad," as defined by the subjects) and minor stressful events, and (2) psychological status and social support. Subjects were also asked about personal medical history, sociodemographics, and side effects of immunization. Subjects with more stressful events (of any type) tended to have lower baseline and 3-week postimmunization IgG levels. Those reporting more "good" events tended to have higher IgG levels at 8 weeks postimmunization. Psychological Distress scores correlated negatively and Psychological Wellbeing scores correlated positively with each IgG level. Subjects with a recent infection (preimmunization) or a local reaction to immunization had significantly higher IgG levels at all three points compared to those without these factors. These data and exploratory analysis suggest that recent stress and psychological status (perhaps representing the cumulative effects of stress and response to stress) may influence immune response to immunization. However, predisposing biological factors must also be assessed for possible confounding in the stress-immune response relationship.