Altered cytokine responses to cognitive stress in multiple sclerosis patients with fatigue

This study intended to examine if the immune response to a cognitive task as a variant of psychological stress in MS patients is distinct from healthy controls. The experiment was part of a larger study on mechanisms and measurements of MS fatigue. Patients (n=23) and controls (n=25) participated in a cognitive task lasting 40 minutes, in which the heart rate was continuously monitored. Blood samples were taken at baseline and directly after the stress-inducing task. Whole blood stimulated cytokine production representative of the TH-1 (i.e. IFNγ, TNFα) and TH-2 paradigm (i.e. IL-10) was evaluated in relation to disability, fatigue, cognitive deficit, and anxiety. Patients scored high on a disease specific fatigue score compared to controls, whereas baseline cytokine patterns did not differ between the groups. MS patients displayed a blunted response of IFNg (P=0.03) whereas TNFα and IL-10 responses did not change. Additionally MS patients showed a significantly lower heart rate increase after the task (P...