Acupuncture in immune homeostasis

January 10, 2014

Acupuncture in immune homeostasis

In the early ‘90s acupuncture was believed to be an efficient analgesic technique.
Many pain conditions that have been treated by acupuncture, such as tendonitis, sinusitis, asthma, osteoarthritis, rheumatoid arthritis, involve inflammation.  Lately, evidence has accumulated regarding the fact that acupuncture has anti-inflammatory effects, in addition to analgesia.
Although opioids are known to have anti-inflammatory properties within the central nervous system and in the periphery, naloxone only partially blocks the anti-inflammatory effect of acupuncture.

Inflammation is a homeostatic response, a reaction to infection, injury or trauma. The onset of inflammation is characterized by release of pro-inflammatory mediators (TNF, IL-1, adhesion molecules, vasoactive mediators and reactive oxygen species). Although, inadequate production of cytokines leads to ongoing (and chronic) inflammation, excessive production can be injurious for the organism. Homeostatic response is balanced by anti-inflammatory factors such as IL-10, IL-4, IL-1 receptor antagonists etc.

All these peripheral molecules, apart from pro and anti inflammatory action, signal inflammation to the brain’s neuro-endocrine pathways, and more specific to the hypothalamo-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS). Both, laboratory and clinical evidence have shown the existence of a cross talking, negative feedback between the autonomic nervous system (mainly sympathetic) and the innate immunity. Recently, Kevin J. Tracey et al, described the anti-inflammatory role of the vagus nerve in animal models, a new pathway of neural inhibition of inflammation.

They proved that cytokines transmit signals to the brain through the vagal sensory neurons (vagotomy inhibits the stimulation of the HPA axis and norepinephrine axis). This is the first reference for the existence of a parasympathetic control on systemic and/or local inflammation. Acetylcholine, the neurotransmitter of vagus nerve, binds to the a7 subunit of the nicotinic acetylcholine receptor (a7nAChR) on macrophages. Stimulation of the afferent pathway of the vagal nerve induces immunosuppression controlling TNF production of the spleen macrophages.

The description of the arc reflex (sensory and motor pathway) through which the vagus nerve participates in immunological homeostasis, was a necessity. The catecholaminergic splenic nerve fibers are the neural connection between the vagus nerve and the spleen macrophages. Animal experiments indicate that vagus nerve drives organisms το achieve  rapid and precise control of inflammation (systemic cytokine production) through celiac-superior mesenteric plexus ganglia.

The question for medical acupuncturists was the following: Is acupuncture a treatment through which the cholinergic anti-inflammatory reflex controls inflammation (decreasing TNF production)?  In our review we will describe the auricular and body acupuncture points which act as immunoregulators through the vagus nerve. These points are in use for centuries by Chinese specialists for the control of symptoms as fever, anorexia, fatigue, somnolence (cytokine overproduction) and they are  considered as a potentially useful treatment of various chronic inflammatory disorders; Chrohn’s disease, rheumatoid arthritis, autoimmune (allergic) diseases, colitis, inflammatory bowel disease, arthritis, type 2 diabetes, atherosclerosis, multiple sclerosis, Alzheimer’s disease etc, where cytokine overproduction has been implicated.

To conclude, we will mention the role of the spleen in controlling inflammation, as the prominent source of TNF-alpha circulation. Our statement proves that spleen, as an organ, is more significant than believed. This perspective comes more in accordance to its role in Traditional Chinese Medicine. This decade opens up a new chapter in research in the field of acupuncture regarding the biological mechanisms involved in its anti-inflammatory action. In the near future, acupuncture will be an absolute indication for treating inflammation – regardless the cause. It will not surprise us the use of acupuncture as an adjunct therapy to the conventional medical treatment of a number of chronic inflammatory and autoimmune diseases.

Karavis Milziade , MD , FICAE , Fisiatra , Pain Specialist

Slides

[print_gllr id=1122]