Chronic Fatigue: Immune System Abnormalities
A number of studies have found many irregularities of the immune system, although there is no consistent pattern. Some components appear to be overreactive, whereas others appear to be underreactive.
Some research has demonstrated that many of chronic fatigue patients are allergic to pollen, food, metals (such as mercury or nickel), etc. Those who additionally suffer from depression or anxiety or depression may be more vulnerable to a damaging over-response to allergens. This triggers the development of many immune factors causing aches, tiredness, and fever, which, in turn, affects the hypothalamus-pituitary-adrenal axis.
The combination of allergic reactions, mental or physical stress, and infection can deplete the body of ATP which stores energy and is reportedly deficient in chronic fatigue patients.
The risk profile for chronic fatigue syndrome is similar to the risk profiles for a number of autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, and multiple sclerosis. These disorders also have early symptoms resembling CFS. Common to such diseases are the presence of high levels of autoantibodies, antibodies that attack the patient's own cells. Some studies are finding high levels of autoantibodies directed against substances in cell nuclei in CFS patients. Others, however, have found no evidence of an autoimmune factor.
Overactive Immune System
One study reported that people with severe CFS symptoms, had very high amounts of white blood cells known as CD8-killer T-cells which fight infection and attack micro-organism invaders. These same patients had very low amounts of another suppessor T-cells, another type of white blood cell that turns off the immune response after the invaders have been destroyed. When this combination occurs, the patients' immune is overactive producing tiredness, aches and other CFS symptoms.
Deficiencies in Natural Killer Cells
Other studies have indicated lower amounts of so-called natural killer cells, (which comprise a major component of the innate immune system) in many CFS patients, which might make them more susceptible to viruses.