Autoimmunity has become a well-known concept in our modern world, although it was not widely accepted in mainstream medicine until the 1950s and 1960s. Many of us have a general idea what the term means or can list a number of autoimmune conditions.
Diseases such as multiple sclerosis (MS), systemic lupus erythmatosis (SLE), type 1 diabetes, Hashimoto’s thyroiditis, Sjogren’s syndrome, rheumatoid arthritis (RA), Crohn’s disease and celiac disease are now widely recognized. Over 23.5 million Americans have an autoimmune disease, and autoimmune diseases have been identified in virtually every organ system.
What is autoimmunity? It literally means “immunity against self” or an immune system mistakenly attacking healthy tissue. The German immunologist and Nobel Laureate, Paul Ehrlich (1845-1915), coined the term horror autotoxicus “the horror of self-toxicity” to describe the body’s aversion to immunological self-destruction. Our bodies are equipped with powerful defenses against invading microorganisms like viruses and bacteria. We have protective mechanisms directing the immune system to distinguish between “self” and “non-self,” preventing the immune system from attacking and destroying healthy tissue.
During an autoimmune reaction, this recognition of “self” is impaired, resulting in an increased immune response. While we all have a small degree of autoimmunity occurring within our bodies, autoimmune diseases develop when benign autoimmunity progresses to pathogenic autoimmunity.
The puzzling question of why our immune systems would initiate an attack on our own tissues is an area of ongoing research. Autoimmunity has been attributed to a number of suspected causes including genetic susceptibility, environmental triggers, and immune dysregulation. While these causes can overlap and interact, there is at this time no single causative factor.
Autoimmune disease symptoms wax and wane, and signs can vary greatly from patient, making diagnosis difficult. Flare ups, or periods of worsening symptoms, are often interspersed with periods of remission or few to no symptoms. Initial autoimmunity symptoms include: fatigue, unexplained rashes, abdominal pain, low grade fever, and malaise, among others. A classic indicator of autoimmunity is inflammation, which may lead to redness, heat, pain or swelling of the affected tissue.
Autoimmunity can be identified by the presence of autoantibodies that are part of the immune reaction to “self.”
A number of lab test parameters are useful. The chart below (click for larger image) provides a summary of autoantibody clinical correlations.
Combining clinical observations, general autoimmune lab tests and disease-specific markers, clinicians improve their chances to diagnose a patient’s autoimmune disease.