Psychological stress and cytokine production in multiple sclerosis: correlation with disease symptomatology.

OBJECTIVE: Psychological variables such as perceived stress appear to play a role in symptom onset or disease exacerbation in multiple sclerosis (MS). The authors sought to determine if perceived stress is indeed associated with the expression of pro-inflammatory cytokines and disease symptoms in individuals with MS. To do so, the authors examined the relationships among disease symptomatology, perceived stress, and cytokine production from peripheral blood mononuclear cells in 42 outpatients with MS and 36 normative controls.
METHOD: The authors drew peripheral blood from all subjects prior to the completion of a series of psychological instruments. The authors measured stress using the Perceived Stress scale and negative mood with the Profile of Mood States. Disease symptoms were measured using the Multiple Sclerosis Symptom Checklist. Cytokine production was induced separately by lipopolysaccharide and a combination of phytohemagglutinin and phorbol-12-myristate-13-acetate.
RESULTS: In MS subjects, the induced production of interleukin (IL)-6 and IL-10 positively correlated with psychological stress, mood disturbance, and disease symptomatology. In contrast, psychological stress in control subjects significantly correlated with level of tumor necrosis factor-alpha (TNF-α), and mood disturbance correlated with levels of TNF-α and interferon-gamma. As well, compared to controls, MS subjects exhibited a significant fourfold increase in the production of IL-12.
CONCLUSION: There is, in those with MS, a pattern of IL-6 and IL-10 production that correlates significantly with perceived stress and disease symptomatology.