Atopic and non-atopic subjects shared some immune changes in response to stress, such as a dramatic decline in cytokines and an increase in the number of regulatory T cells in peripheral blood. However, other stress-induced immune changes were unique to atopic individuals, such as a skewed Th1/Th2 ratio and reduced NK cell numbers, indicating that some pathogenic mechanisms in atopics may be more strongly affected by stress than others.

Atopic students were worse off in aspects of psychological well-being and sleep, but displayed only partly stronger responses to a stressor compared to non-atopic students. In spite of a broad negative response to examination, allergic symptoms were not affected.

Objective: The balance between glucocorticoid (GC) release and GC sensitivity in target cells is believed to be important to maintain homeostasis in the neuroendocrine control of inflammation. We investigated the impact of in vivo exposure to adrenocorticotropic hormone (ACTH) and dexamethasone (DEX) on GC sensitivity measured in vitro in healthy individuals with high versus low baseline cortisol levels. Methods:136 healthy male volunteers were screened twice and sorted according to their 24-hour urinary free cortisol (UFC) excretion. The 10 individuals with the highest UFC (290 ± 87 nmol/24 h) and the 10 with the lowest UFC (168 ± 34 nmol/24 h) were further tested. Measurements were performed at baseline, after a low dose (0.5 μg/1.73 m²) of ACTH challenge and after 2 weeks’ exposure to DEX (0.1 mg twice daily). GC sensitivity was assessed in vitro as the ability of DEX to inhibit lipopolysaccharide-stimulated production of the cytokines interleukin 1-β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in a whole-blood assay. Results:After exposure to DEX in vivo, inhibition of IL-6 and TNF-α decreased. Also, after DEX in vivo, low-cortisol men showed lower inhibition of IL-1β and IL-6, both compared to the high-cortisol group and their own baseline levels. Conclusion: A downregulation of GC sensitivity in leukocytes after exposure to an exogenous GC seems to occur most strongly in men with low cortisol levels.

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