. . . . "Immune activation is known to be elevated in patients with MS, and the proinflammatory cytokines involved may be the cause of the HPA axis alterations and a strong feeling of fatigue in patients with MS. Studies in patients and animals with MS found an association between fatigue and some proinflammatory cytokines, including tumor necrosis factor ?? and IL-1,5,31,32 which are known to activate the" .