A recent study study looking at the significance of genes associated with nervous, hormonal and immune abnormalities in chronic fatigue syndrome patients finds a link between them.
For a long time it has been known that both the nervous and endocrine (hormonal) systems are responsible for control of bodily functions and maintaining a state of healthy balance (homeostasis). Over the past few decades it has also become clear that both of these systems are also intimately linked to the immune system and its function.
A new term, "neuroendocrinimmunology" was coined around 20 years ago to describe this connection between the three systems. According to a paper by Reichlin (1993) neuroendocrinimmunology is defined as "the study of neuroendocrine influences on the function of immunocompetent cells", i.e. the influence of the nervous and endocrine systems on immune cells. It also became clear that the communication was a two-way thing however so the subject of neuroendocrinimmunology also includes the way the immune system affects the nervous and endocrine systems.
This subject has been found to have major implications for chronic fatigue syndrome (ME/CFS) as research studies have found abnormalities in all three systems e.g. hypothalamic dysfunction (nervous system), low cortisol and blunted adrenal gland response to stimulation (endocrine system), low natural killer (NK) cell numbers, increased inflammatory and allergic responses (immune system).
Now researchers at the Department of Medicine, University of Alberta; Walter Mackenzie Health Sciences Centre, in Edmonton, Canada have looked specifically the significance of changes in association patterns (of genes) linking indicators of neuroendocrine and immune activity in patients with ME/CFS.
Genes associated with specific immune cells were compared with information about nervous system and hormone function in both ME/CFS patients and healthy individuals in a large population based study.
Genetic information linking immune cell activity with hypothalamic-pituitary-adrenal (HPA), thyroidal (HPT) and gonadal (HPG) axis status was analyzed. Essentially the researchers were looking at how the activity of the immune system was associated with production of adrenal hormones (e.g. cortisol), thyroid hormones, and sex hormones and how this differed between ME/CFS patients and healthy people.
According to the researchers the results indicate statistically significant differences between ME/CFS and healthy subjects and that these seem to center around the function of the pituitary and thyroid glands.
The results are interesting as ME/CFS specialists such as Dr. Jacob Teitelbaum in the US and Dr. Sarah Myhill in the UK have had success improving patients' symptoms by addressing issues with thyroid function, along with adrenal issues.
The Canadian scientists conclude that their study findings "align with known mechanisms of chronic inflammation and support possible immune-mediated loss of thyroid function in CFS exacerbated by blunted HPA axis responsiveness."
Source: Fuite J Vernon SD Broderick G (2008) Neuroendocrine and immune network re-modeling in chronic fatigue syndrome: An exploratory analysis Genomics [Epub ahead of print] PMID: 18775774