Autoimmune Disease; what and why


Autoimmune disease is on the rise.  One in twelve Americans -and one in nine females- will develop some form of autoimmune disease in their lifetime.  Between 2001 and 2009, rates of type 1 diabetes increased by 23%.  Depending on who you ask, anywhere from 80 to 100 types of autoimmune diseases have already been discovered, with roughly 40 more diseases suspected of being autoimmune in nature.  That frustrating recurring eczema?  Yep, count it.

The manifestations of autoimmune disease are as varied as their names.  There’s vitiligo, where pigment is no longer produced in certain areas of the skin, or multiple sclerosis, where the myelin sheaths around the neurons are attacked.  Crohn’s disease and ulcerative colitis both result in bloody bowel movements and malabsorption of nutrients.  Graves disease sends the thyroid into a frenzy, causing heart palpitations, anxiety, weight loss, and sweating.  Autoimmune disease is like the oddest of odd families.

So what, exactly, does "autoimmune" mean?  

Autoimmune disease is the body’s failure to recognize “self.”  This results in the immune system launching an attack on an organ or tissues of the body.  It may be systemic, as seen in scleroderma and lupus, or organ-specific, as is the case in type I diabetes or Addison’s disease.  The longer the attack lasts, the more internal destruction is caused.  For many patients, the disease will fluctuate from highly disruptive, active “flares” to periods of remission or near remission, usually drug induced.  In some patients, symptoms are vague and confusing enough that they may struggle for years without a clear diagnosis, as is often seen with fibromyalgia or Hashimoto’s thyroiditis.  When left untreated, patients with one autoimmune disease show a higher risk of developing other ones over time.

They're flaring!

They're flaring!

Shoot.  Scary stuff.  So what causes autoimmune disease?

It’s been historically difficult to connect the dots on what causes autoimmunity.  Partly at fault is the structure of allopathic medicine.  As Dr. Terry Wahls explains in her book on autoimmune disease, The Wahls Protocol, today's medical world categorizes disease by its symptoms and by what medication it responds to.  Looking at autoimmune disease through a wide variety of narrow lenses makes it difficult to flesh out the deeper cause and nature of the disease.  Instead of autoimmune specialists, patients see doctors specializing in their organ or tissue under attack.  The result can be frustrating; no matter how well trained a doctor is in the field of gastroenterology, for example, he or she may not have a strong understanding of the autoimmune nature of Crohn’s or colitis.  The result is an overemphasis on treating the symptoms without addressing the root cause. 

But we’re not entirely in the dark.  One factor that has been identified in the development of autoimmune disease is genetics.  As Sarah Ballantyne, Ph. D., a researcher in the field writes:

“autoimmune disease is a result of the interactions between your genes and your environment- a perfect storm of factors that cause the immune system to be unable to distinguish self (you) from invader (not you)” 

Scientists have identified many genetic variations and snips that predispose an individual towards developing certain types of autoimmunity.  If these genetically-predisposed individuals meet their “perfect storm,” the immune system is tripped and autoimmunity develops.

What of the other two thirds?  For most patients, there’s an environmental trigger.  This may be an overload of toxins; heavy metals, such as mercury, cadmium, and lead, have been shown to cause autoimmunty in rat studies.  Sometimes it’s triggered by medications, as seen in the development of certain types of systemic autoimmunity.  It may be linked to chemicals in commercial foods and products, such as tetramethylpentadecane, a hydrocarbon found in mineral oil and other processed foods which has been shown to increase inflammation and the development of autoimmunty in rat studies. 

Bacterial, fungal, parasitic, and viral infections are another possible trigger of autoimmunity.  Even when mild in nature, their presence can stir the immune system into a chronic inflammatory state that results in an inability to differentiate self from invader.  Many relatively common infections have been linked to various types of autoimmunity, including H. pylori, T. gondii, Epstein-Barr, B. bergdorferi, and enterovirus.  Interestingly, the opposite appears to be true as well.  With the near elimination of some types of parasites from our bodies, an increase in allergies and inflammation has been seen.  Scientists are currently studying how and why low-grade helminth infections seem to have a modulating effect on the immune system and are particularly helpful in reducing symptoms of inflammatory bowel disease and allergy development.  Check out Radiolab's story of the man who gave himself worms on purpose for more!  

When it comes to the last third factor for developing autommunity, most doctors give it a shrug and a shake of the head.  But some researchers and scientists are beginning to point the finger at a condition known as leaky gut.

Leaky gut is a popular buzzword in today’s health and wellness world.  What might get an eye roll from your doctor, however, gains credibility under the term “intestinal permeability,” a very real diagnosis.  When it’s present, the junctions between the cells lining the intestinal tract -normally snug enough to allow only single molecules of digested food to pass through- become weak and loose.  The leakier these gaps get, the more partially digested food fragments are able to pass through the gut lining and into the bloodstream.  Not only can these particles alarm to the immune system, but some proteins, such as gluten and casein, can damage the body by resembling internal tissues and causing the immune system to turn on these cells.  This is called “molecular mimicry” and is thought to play a role in many forms of autoimmune disease.

Your gut, on trigger foods.

Your gut, on trigger foods.

Leaky gut is thought to be caused by the cumulative effect of diet, inflammation, and unhealthy gut flora.  It may also be a reaction to certain foods.  Gluten, for example, has been shown to have a direct effect on weakening the gut lining by signaling zonulin, the protein responsible for keeping these junctions snug.

There are other factors at play in the development of autoimmunity, such as nutrient levels.  A deficiency in vitamin D, for example, results in a failure of the immune cells that are supposed to moderate the immune response.  In this case, instead of the body adapting to a harmless trigger, the immune response spirals out of control and into autoimmunity.

Hormones also play a complex but little-understood role in autoimmunity.  Some autoimmune diseases tend to arrive with the onset of puberty, while others can delay its start.  Women have widely varying symptoms of active autoimmune disease depending on where they are in their cycle.  Likewise, pregnancy may put a flare into remission or cause a series of them.  Some hormones have been shown to be pro-inflammatory, which likely plays a role in triggering the development of autoimmunity.  Others are anti-inflammatory.  When these hormones are in motion, such as during a woman’s regular menstrual cycle, or in flux, such as during puberty or menopause, autoimmunity may be triggered or repressed.

Autoimmune disease is a complex little beast but amidst all the factors and variables, glimmers of clarity are shining through.  The silver lining to the surge in numbers is that we're amassing healing wisdom at a rapid pace, thanks to the tireless work of scientists, doctors, and countless inspirational individuals.  

Join me for the next post of this series, where we'll explore treatment options for autoimmunity.