Immune System

The common view among both the general public and the medical profession is that the immune system runs on "autopilot", constantly looking out for infections and mounting an immune response when an infection occurs. Research shows, however, that the health of the immune system can vary widely, and that in some people certain parts of the immune system can become suppressed.

Although it is known that stress can suppress the immune system, through the action of adrenaline and cortisol, recent research shows the HPA axis can actually have a positive effect on the immune system, reversing the effects of cortisol and increasing the killing ability of natural killer (NK) cells.

Research shows that many CFS patients have a shift towards the Th2 immune response, as well as having a lower than normal immune response in general. The Th2 immune response is used by the body to fight bacterial and parasitic infections, while the Th1 response is used against viruses and cancer. The shift towards the Th2 subsystem which is seen in CFS patients results in higher levels of allergies (which are caused by the Th2 immune response) and a reduced immunity to viral infections. These changes in immune function are likely to be due to the underlying abnormalities in the HPA axis seen in CFS patients, rather than being due to any ongoing infection.

Research also shows that personality has a large influence over immunity, and NK cells in particular. People who have poor coping strategies for dealing with stress and who are more anxious tend to have reduced NK cell activity. This is likely to be due to higher activation of the sympathetic nervous system, resulting in higher levels of adrenaline and noradrenaline in the bloodstream.

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