Stress-induced immune conditioning affects the course of experimental peritonitis.

Septic patients show individually different courses of disease that are hard to predict. Little is known about preconditioning influences that may render one person liable to have overwhelming hyperinflammatory response syndrome (systemic inflammatory response syndrome) and another from compensatory anti-inflammatory response syndrome. Here, we show in a murine model that chronic psychological stress before the onset of polymicrobial peritonitis influences the balance between both types of immune response. Chronically stressed mice which had increased lymphocyte apoptosis, severe functional lymphocyte defects, and an anti-inflammatory cytokine bias had a reduced mortality rate during the continuous outflow of gut content in the hyperinflammatory sepsis model of colon ascendens stent peritonitis. In contrast, they had enhanced long-lasting bacterial dissemination in a sepsis model of mild cecal ligation and puncture. Chronic stress therefore is an important preconditioning factor in the individuals' ability to cope with systemic infections after abdominal surgery. It ameliorates lethal shock responses but reduces the capacity to eradicate bacterial infection during mild peritonitis.