Table of Contents

• The Diverse Array of Autoimmune Diseases
• What Causes Autoimmune Diseases?
• Are Genes Involved in Autoimmune Diseases?
• Increasing Prevalence
• Pacific Northwest Connection
• Common Threads
• Research Advances

Autoimmune diseases strike one in 15 Americans including about 18 million women and 5 million men. Autoimmune diseases are among the top 10 causes of death in female children and women in all age groups up to 64 years of age. The National Institutes of Health estimate autoimmune diseases cost an estimated $100 billion a year in medical care.

There are approximately 110+ different types of autoimmune diseases. However, all autoimmune diseases have one thing in common: the immune system – which is designed to protect the body against infection - makes a mistake and attacks its own healthy tissue.

The Diverse Array of Autoimmune Diseases

Autoimmune diseases include illnesses throughout the body such as:

• skin (psoriasis)
• joints (rheumatoid arthritis)
• nervous system (multiple sclerosis)
• gut (ulcerative colitis and Crohn’s disease)
• endocrine system (type 1 diabetes and thyroid disease)

No tissue or organ is exempt from autoimmune diseases. They affect many different organs and vary greatly among the individuals who have them, in terms of their severity and the responsiveness to therapy. This level of complexity is reflected in the underlying causes of autoimmune diseases, including multiple genetic and environmental factors. And because many causes of autoimmune diseases are shared, people living with an autoimmune disease are more likely to suffer from more than one of these destructive diseases.

What Causes Autoimmune Diseases?

What causes the immune system to no longer tell the difference between healthy body tissues and an infection is unknown. One theory is that bacteria, viruses, toxins or drugs may trigger some of these changes, especially in people who have genes that make them more likely to develop autoimmune disorders.

The immune system is complex and has evolved redundant pathways over millennia in response to diverse challenges. Therefore, scientists think that immune dysfunction will need to be treated with combinations of approaches.

Are Genes Involved in Autoimmune Diseases?

Inherited genes play an important role in determining risk of autoimmune diseases. Some genes confer a large risk, other genes confer a small risk, and some genes even provide protection from autoimmunity.

In general, risk is increased among close relatives within a family who have autoimmune diseases, due to the likelihood that genes are shared. That risk ranges from a few percent increase all the way up to an increase of 10- to 20-fold. However, even with these large increases, the overall disease risk can be fairly small. For example, an increased 10-fold risk for an autoimmune disease that occurs in 1 in 1,000 people means that the risk becomes 1 in 100. So while family members have a high likelihood of inheriting disease-associated genes, and they are at higher than normal risk of also getting autoimmune diseases, in most cases the odds are still reasonably low.

Increasing Prevalence

The incidence of many autoimmune diseases is increasing, including multiple sclerosis (MS), inflammatory bowel disease (IBD) and type 1 diabetes (T1D). There is much ongoing analysis to determine why this is occurring. The increase in autoimmune disease prevalence may be due to changes in several aspects of the environment that disturb the balance of the immune system. These changes make it more likely that someone susceptible to one of these diseases will actually develop it.

Pacific Northwest Connection

In the Pacific Northwest there is a greater prevalence of autoimmune diseases such as MS, IBD and T1D.

IBD affects approximately 1.4 million Americans (almost 1 in 200), evenly divided between Crohn’s disease and ulcerative colitis. IBD is more common in northern latitudes, like the Pacific Northwest, where an estimated 50,000 patients are thought to reside. Some likely factors that contribute to this geographic effect are vitamin D deficiency from lack of natural sunlight, genetic predisposition in the Northern European/Scandinavian heritage and unknown environmental triggers.

MS affects approximately 400,000 Americans (1 in 1,000) but is much more common in the Northwest where approximately 12,000 (2 in 1,000) people have MS. Some likely factors that contribute to this may be vitamin D deficiency, genetic predisposition and environmental triggers. Other factors are still unknown.

Common Threads

What if medical research could discover the commonalities between these diseases and find therapies that work for more than one disease? That’s exactly what Benaroya Research Institute at Virginia Mason (BRI) is doing. The scientists aren’t focused on eliminating one or two autoimmune diseases – they’re taking on all 110+.

The illustration below shows the connection between genes and multiple autoimmune diseases. These genes are common in two, three or four diseases. As BRI looks for new therapies to affect these genes in one disease, they are also applied to others.

BRI scientists work together to study the genes, molecules, cells and function of the immune system to discover the common elements that – no matter what type of tissues is affected – will explain the disease course and help identify the best approach for therapy.

Bringing together researchers and clinicians studying multiple autoimmune diseases is a catalyst for discovery – learning how similar mistakes by the immune system can cause different diseases and using this information to test therapies that have been initially developed for one disease and applying them to a different disease.