Enhancing versus suppressive effects of stress on immune function: implications for immunoprotection and immunopathology.
Level 5 - mechanism / opinion, no new human data
Narrative review and theoretical synthesis without systematic review methodology.
PubMed 19571591 · doi:10.1159/000216188
What was done
This narrative review synthesizes literature and conceptual models examining how stress and stress hormones (endogenous and synthetic glucocorticoids) differentially enhance or suppress innate and adaptive immune function.
What was found
The abstract reports no quantitative data or statistical estimates. It identifies four critical determinants of stress-induced immune modulation: (1) Duration: acute short-term stress during immune activation enhances innate and adaptive responses, whereas chronic stress decreases cell counts/function, promotes regulatory T cells, and dysregulates proinflammatory/type-2 cytokine responses. (2) Leukocyte redistribution: compartments enriched with trafficking leukocytes exhibit immunoenhancement, while depleted compartments show immunosuppression. (3) Hormone concentration and source: physiological endogenous glucocorticoid levels can enhance immunity, whereas pharmacological concentrations and synthetic glucocorticoids are immunosuppressive. (4) Timing: stress during initial immune activation enhances the response, whereas stress at later stages suppresses it.
Why it matters
It reconciles the paradox of stress causing both immunosuppression and the exacerbation of inflammatory or autoimmune disorders by distinguishing adaptive acute stress responses from maladaptive chronic stress states.
Limits
As a narrative review, it provides no systematic search strategy, meta-analytic data, effect sizes, or confidence intervals. The abstract does not distinguish between findings derived from animal models, in vitro experiments, or human clinical studies.
Cited by
- supports Short-term acute stress boosts and activates the immune system.