Autoimmune diseases are a case of misidentification in which the body's immune system, which normally attacks intruders such as viruses and bacteria, attacks itself. There are more than 100 different autoimmune diseases, some of which affect one organ ( such as Hashimoto's thyroiditis ), while others affect almost any organ or tissue (such as lupus).
The first symptoms, such as fatigue and joint pain, resemble those of other diseases, making diagnosis difficult. These conditions can be temporary or, more often, lifelong. They are sometimes referred to as 'invisible disabilities' because people may not appear to be ill despite serious problems.
More than 23.5 million Americans have autoimmune diseases, and more and more diseases are associated with autoimmunity.
The immune system protects us from viruses, bacteria, foreign substances, and even cancer cells, but it does so with a delicate balance. Without a good immune response (insufficient activity of the immune system), even minor infections can be fatal. However, an overactive immune response (as in autoimmune diseases) can lead to illness and possibly death.
When, say, a virus enters the body, it triggers an immune response . Lymphocytes and other immune cells rush to the rescue, creating inflammation. T lymphocytes are part of the innate response and work to eliminate any type of intruder. B lymphocytes are part of the learned response and produce antibodies that specifically target the threat.
The immune system generally does not attack the body's own cells, and there are several regulatory steps (such as helper T cells) that work to prevent autoimmunity. But it happens.
There are several different ways that an autoimmune reaction occurs. This includes:
- When a foreign substance or microbe resembles a body: An example of this is rheumatic fever , in which the proteins found in group A streptococcal bacteria resemble those in heart muscle; as a result, the antibodies attack the heart.
- When normal cells in the body are changed: An example of this mechanism is a virus that alters a cell in the body so that the immune system recognizes it as "foreign."
- When immune cells that make antibodies ( B-cell lymphocytes ) fail and produce abnormal antibodies that attack normal cells in the body.
- When a substance in the body that is normally hidden from the immune system (such as eye fluid) enters the bloodstream and triggers a reaction.
Autoimmunity does not necessarily mean an autoimmune disease. For example, the body can produce antibodies against itself (autoantibodies), which are involved in cleaning up trash after an infection. In an autoimmune disease, the reaction causes inflammation and tissue damage.
Types of autoimmune diseases
Autoimmune diseases can affect one or more organs. Each disease is characterized by unique antibodies that detect and target specific proteins to cells, called antigens. Some of these antigens are found in one organ (causing an organ-specific autoimmune disease), while others exist in many organs (causing a generalized or systemic autoimmune disease).
Organ specific autoimmune diseases
Some of the more common organ-specific autoimmune diseases include:
Autoimmune thyroid disease
Autoantibodies can cause destruction of thyroid tissue and hypothyroidism, as in Hashimoto's thyroiditis, or stimulation of thyroid tissue and hyperthyroidism, as in Graves' disease . In both conditions, symptoms can develop quickly or slowly over time. Autoimmune thyroid disease is very common and is considered underdiagnosed.
Hypothyroidism can cause symptoms such as fatigue, weight gain, constipation, and hair loss, and this condition is treated with thyroid hormone replacement medications for life.
In contrast , hyperthyroidism often causes nervousness, anxiety, sweating, and heat intolerance, and can be treated with antithyroid medications, surgery, or radioactive iodine therapy to destroy the gland.
Type 1 diabetes mellitus
Type 1 diabetes , which often occurs in childhood or adolescence, occurs when autoantibodies destroy the beta cells of the pancreas, which are responsible for the production of insulin. Symptoms can include thirst, increased urination, and, in severe cases, diabetic coma.
Psoriasis occurs when the immune system mistakenly signals skin cells to grow too fast. There are several forms of psoriasis, the most common of which is plaque psoriasis. Plaque psoriasis is characterized by raised (often itchy) red patches called plaques that occur most often on the knees, lower back, scalp, and elbows.
Treatment options for psoriasis depend on the type and severity. It is important for people with psoriasis to be screened for an associated autoimmune disease called psoriatic arthritis .
Multiple sclerosis (MS) is a condition in which autoantibodies attack the fatty membrane (myelin) that lines the nerves and is necessary for the nerves to function properly. The disease can have many different symptoms depending on the specific area of the nervous system affected, but can include vision problems, sensory disturbances such as numbness and tingling, bladder problems, weakness, loss of coordination, tremors, and more.
Guillain-Barré syndrome (GBS) is a condition in which autoantibodies attack the supporting cells that line the nerves. This often occurs after a viral infection (and rarely after a flu shot), and parts of the infectious organism are thought to resemble parts of the nervous system.
GBS often begins with weakness and sensory changes in the feet and hands. As the condition progresses in the body, it can be life-threatening without immediate medical attention. (Paralysis of the diaphragm requires ventilator-assisted ventilation.)
Systemic autoimmune diseases
Systemic autoimmune diseases can cause many different problems, as their effects are felt throughout the body. Examples include:
Systemic lupus erythematosus
Systemic lupus erythematosus (lupus) is an autoimmune disease that affects multiple organs and has widespread consequences. Symptoms of lupus can include joint pain, rash, kidney problems, inflammation of the lungs and / or heart, anemia, increased blood clotting (thrombosis), memory problems, and more.
Joint deformity generally occurs without early and aggressive treatment. Usually the same joints on both sides of the body are affected, and the small joints in the hands and feet are often affected. In addition to joint inflammation ( synovitis ), people with RA can develop lumps under the skin (subcutaneous nodules), pleural effusion , inflammation of the inner lining of the heart ( pericarditis ), and more.
Inflammatory bowel disease
Inflammatory bowel disease (IBD) , which includes Crohn 's disease and ulcerative colitis , refers to chronic inflammation of the digestive tract. While Crohn's disease can cause inflammation from the mouth to the anus, the inflammation in ulcerative colitis affects only the colon and rectum. Symptoms can include diarrhea, abdominal pain, bloody stools, weight loss, and fatigue.
Treatment often involves a combination of medications and surgery, as well as close monitoring, as both conditions are associated with an increased risk of colon cancer .
In Sjogren's syndrome (SJS), autoantibodies attack the glands that produce tears and saliva. This leads to dry eyes, dry mouth, and related consequences like tooth decay, loss of taste, etc. Joint pain and other symptoms can also occur.
In about half of people with SJS, the syndrome occurs on its own, while in others it is associated with another autoimmune disease such as lupus, rheumatoid arthritis, or scleroderma .
Antiphospholipid syndrome is a common autoimmune disorder in which autoantibodies against certain proteins in the blood are involved, resulting in abnormal clotting. It is often first diagnosed in women as the cause of frequent miscarriages or premature births, or when blood clots and / or bruising occur for no apparent reason.
Clots can also cause heart attacks (when they occur in the blood vessels of the heart) or strokes (when clots develop in the brain).
While the symptoms of autoimmune diseases can vary widely depending on the specific organ or organs affected, there are some symptoms that are common to many of these diseases. Because these symptoms are not specific, they can also be a sign of a non-autoimmune disease.
Common symptoms can include :
- Mild fever (fever usually comes and goes)
- Weight changes
- Pain and swelling of muscles and / or joints
- Difficult to focus
- Digestive problems
- General discomfort
Symptoms often have a recurring and recurring (increasing and decreasing) course, where the disease worsens, improves, and then worsens again in unpredictable ways. Exacerbations can occur, defined as the sudden onset of severe symptoms .
Specific symptoms of the disease.
Specific symptoms depend on the underlying disorder and may include:
- Joint symptoms such as joint redness, pain, and swelling that are more severe than you would expect with osteoarthritis.
- Skin rash, like a butterfly-shaped rash on the face with lupus.
- Vasculitis , inflammation of the blood vessels that can damage wherever the blood vessels are affected (such as aneurysms )
Many autoimmune diseases can be suspected based on a specific combination of symptoms, although two people can have the same diagnosis and a completely different combination of symptoms.
For example, scleroderma is characterized by CREST syndrome (accumulation of calcium in the tissues), Raynaud's syndrome (in which the hands turn cold and blue when exposed to cold temperatures), esophageal dysfunction, sclerodactyly (in which the fingers resemble sausages) and telangiectasia (spider veins) .
It is not uncommon for people with one autoimmune disease to develop another. It could be due to a genetic predisposition or a common trigger.
In general, about 25% of people with one autoimmune disease will develop another.
An example is the combination of rheumatoid arthritis with autoimmune thyroiditis, or the combination of celiac disease with type 1 diabetes, autoimmune liver disease, or rheumatoid arthritis.
The term " multiple autoimmune syndrome " is used to describe people with three or more autoimmune diseases. There are different types of this syndrome, but often one of the three conditions is related to the skin (such as alopecia areata or vitiligo ).
There are believed to be a number of factors underlying the development of autoimmune diseases, as well as factors associated with increased risk.
Possible causes of autoimmune diseases and / or exacerbations include:
- Infectious diseases: Autoimmunity is believed to occur when a component of a virus or bacteria resembles the proteins in the body, or when an infection "strengthens" the immune system. Some specific microorganisms associated with autoimmune diseases include Epstein-Barr virus (EBV) , cytomegalovirus (CMV) , and group A Streptococcus bacteria.
- Environmental factors: Lack of sunlight, vitamin D deficiency, chemical exposure, and other environmental factors are associated with various types of autoimmune diseases. Several studies have also linked autoimmune diseases to an overly sterile environment. The "hygiene hypothesis" is the theory that people exposed to fewer antigens are more likely to have a dysfunctional and overactive immune response.
- Lifestyle: Smoking appears to triple the risk of developing rheumatoid arthritis and is also linked to other autoimmune diseases such as Graves' disease and multiple sclerosis. Obesity is considered a pro-inflammatory condition that can be a risk factor. A Western diet (rich in fat, sugar, protein, and salt) can also contribute to the development of autoimmune diseases.
- Gut Bacteria – More and more research points to a link between the balance of bacteria that live in the human digestive tract ( intestinal flora ) and a number of diseases, including autoimmune diseases.
- Genetics: Some autoimmune diseases seem to run to varying degrees in families, and specific genes are being investigated.
Risk factors differ based on the specific condition, but include:
- Sex – Many autoimmune diseases are more common in women. Additionally, hormonal factors can contribute to aggravating many of these conditions.
- Age: Many autoimmune diseases first appear during the childbearing years.
- Weight – Some autoimmune diseases are more common in overweight people, while others are more common in people with eating disorders.
- Ethnicity: Conditions vary: Type 1 diabetes is more common in white people, and serious autoimmune conditions are more common in blacks, Hispanics, and Native Americans.
- Geography: Certain autoimmune diseases such as MS, IBD, and type 1 diabetes are more common in northern latitudes, where a lack of natural light can contribute to vitamin D deficiency.
- Smoking: Tobacco use is associated with an increased risk of many of these conditions.
- Medications: Certain medications can increase the risk of certain conditions, such as novocainamide and lupus .
Diagnosing an autoimmune disease can take time and sometimes multiple opinions. In fact, unfortunately, the average person spends four and a half years (visiting at least four doctors) before being diagnosed .
When to start
People are encouraged to start with a specialist who deals with their most serious symptoms, such as seeing a rheumatologist if joint symptoms are frequent. After that, you may need to consult additional specialists.
The diagnostic process begins with a complete medical history, although this can be frustrating as many people have seemingly unrelated symptoms. Physical examination can sometimes indicate an autoimmune condition based on joint swelling, characteristic rashes, etc., but more tests are more often required.
There is no single test that can definitively diagnose autoimmune diseases (with rare exceptions, such as type 1 diabetes), and the evaluation usually includes a number of tests, including:
There are many other tests that may be recommended depending on the condition you suspect.
Imaging tests can be used to evaluate specific symptoms associated with autoimmune diseases, such as X-rays of swollen joints or an echocardiogram (ultrasound of the heart) if pericardial effusion is suspected.
Treatment of autoimmune diseases depends on the specific disease. For many of these conditions, the course is unpredictable and treatment may need to be changed over time.
In general, treatment can be considered to consist of:
- Symptom management: For example, nonsteroidal anti-inflammatory drugs (NSAIDs) can be used to relieve joint pain.
- Hormone replacement therapy: For conditions such as type 1 diabetes or autoimmune hypothyroidism, insulin or thyroid hormone is prescribed.
- Inflammation control : Medications such as corticosteroids and tumor necrosis factor inhibitors ( biologics ) are needed to control the inflammation associated with many autoimmune diseases.
- Complication prevention: People with type 1 diabetes need tight blood sugar control to reduce complications, while rheumatoid arthritis requires early and aggressive treatment to prevent joint deformities.
In some cases, an autoimmune disease can be curable, but for most of them, the main goal is remission or control of the disease.
Clinical trials are also underway to find new and more effective treatments for these conditions.
Most autoimmune diseases are relapsing and remitting diseases . It's hard to predict when it will feel good and when it won't. Additionally, many people with these disorders appear healthy on the outside, sometimes resulting in less understanding and support from friends and family.
However, there are many things that people with autoimmune diseases can do on their own to better cope with everyday symptoms and disorders:
- Eat a healthy diet: For people with diabetes, it is very important to control your diet. For other people with autoimmune diseases, a diet that promotes the growth of healthy gut bacteria can be beneficial.
- Practice good sleep hygiene: Get plenty of rest each night and try to wake up and go to bed at the same time each day.
- Exercise: Light to moderate exercise is important to most people, but it's just as important to take your time and know when to stop.
- Practice stress management: Stress management can help you cope with any medical condition and is especially important for stressful conditions like autoimmune diseases.
- Know your triggers: In some conditions, there are triggers that are associated with flare-ups. It helps to identify them and then look for ways to reduce the impact.
Anyone dealing with a serious illness needs support, but this is even more true for those living with "invisible illnesses." Personal support groups and online support communities can be helpful as they provide an opportunity to connect with others who are similarly dealing with unpredictable and often misunderstood conditions.
Some groups are based on certain conditions, while others are based on symptoms. The National Coalition of Autoimmune Patient Groups is a good place to start looking for these communities.
Get the word of drug information
If you or your loved one is battling an autoimmune disease, it is important to be your own advocate. The road to diagnosis and then to effective treatment can be frustrating and even lonely. Fortunately, there is a great deal of research on the causes and treatments for these conditions.