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Everything To Know About Autoimmune Diseases
Autoimmune diseases are conditions in which your immune system mistakenly damages healthy cells in your body. Types include rheumatoid arthritis, Crohn's disease, and some thyroid conditions.
Your immune system usually protects you from diseases and infections. When it senses these pathogens, it creates specific cells to target foreign cells.
Usually, your immune system can tell the difference between foreign cells and your cells.
But if you have an autoimmune disease, your immune system mistakes parts of your body, such as your joints or skin, as foreign. It releases proteins called autoantibodies that attack healthy cells.
Some autoimmune diseases target only one organ. Type 1 diabetes damages your pancreas. Other conditions, such as systemic lupus erythematosus, or lupus, can affect your whole body.
Below we provide an overview of some of the most common autoimmune diseases.
Doctors don't know exactly what causes the immune system to misfire. Yet some people are more likely to get an autoimmune disease than others.
Some factors that may increase your risk of developing an autoimmune disease can include:
Different autoimmune diseases may have similar early symptoms. These can include:
With some autoimmune diseases, including psoriasis or rheumatoid arthritis (RA), symptoms may come and go. A period of symptoms is called a flare up. A period when the symptoms go away is called remission.
Individual autoimmune diseases can also have their own unique symptoms depending on the body systems affected. For example, with type 1 diabetes, you may experience extreme thirst and weight loss. Inflammatory bowel disease (IBD) may cause bloating and diarrhea.
Researchers have identified more than 100 autoimmune diseases. Here are 14 more common ones.
1. Type 1 diabetesYour pancreas produces the hormone insulin, which helps regulate blood sugar levels. In type 1 diabetes, the immune system destroys insulin-producing cells in your pancreas.
High blood sugar from type 1 diabetes can damage the blood vessels and organs. This can include your:
In RA, your immune system attacks the joints. This causes symptoms affecting the joints such as:
While RA more commonly affects people as they get older, it can also start as early as your 30s. A related condition, juvenile idiopathic arthritis, can start in childhood.
3. Psoriasis/psoriatic arthritisSkin cells grow and then shed when they're no longer needed. Psoriasis causes skin cells to multiply too quickly. The extra cells build up and form inflamed patches. On lighter skin tones, patches may appear red with silver-white scales of plaque. On darker skin tones, psoriasis may appear purplish or dark brown with gray scales.
Up to 30% of people with psoriasis also develop psoriatic arthritis. This can cause joint symptoms that include:
4. Multiple sclerosisMultiple sclerosis (MS) damages the protective coating surrounding nerve cells (myelin sheath) in your central nervous system. Damage to the myelin sheath slows the transmission speed of messages between your brain and spinal cord to and from the rest of your body.
This damage can lead to:
Different forms of MS progress at different rates. Difficulties with walking are one of the most common mobility issues with MS.
5. Systemic lupus erythematosus (SLE)Although doctors in the 1800s first described lupus as a skin disease because of the rash it commonly produces, the systemic form, which is most common, actually affects many organs. This can include your:
Common symptoms can include:
IBD describes conditions that cause inflammation in the lining of the intestinal wall. Each type of IBD affects a different part of your gastrointestinal (GI) tract.
Common symptoms of IBD can include:
Addison's disease affects the adrenal glands, which produce the hormones cortisol and aldosterone as well as androgen hormones. Too little cortisol can affect how your body uses and stores carbohydrates and sugar (glucose). Too little aldosterone can lead to sodium loss and excess potassium in your bloodstream.
Common symptoms of Addison's disease can include:
Graves' disease attacks the thyroid gland in your neck, causing it to produce too much of its hormones. Thyroid hormones control the body's energy usage, known as metabolism.
Having too much of these hormones revs up your body's activities, causing symptoms that may include:
Some people with Graves' disease may also experience symptoms affecting the skin (Graves' dermopathy) or eyes (Graves' ophthalmopathy).
9. Sjögren's diseaseThis condition attacks the glands that provide lubrication to your eyes and mouth.
The hallmark symptoms of Sjögren's disease are dry eyes and dry mouth, but it may also affect your joints or skin.
10. Hashimoto's thyroiditisIn Hashimoto's thyroiditis, thyroid hormone production slows to a deficiency. Common symptoms of Hashimoto's thyroiditis can include:
11. Myasthenia gravisMyasthenia gravis affects nerve impulses that help the brain control muscles. When the communication from nerves to muscles is impaired, signals can't direct the muscles to contract.
The most common symptom is muscle weakness. It may worsen with activity and improve with rest. Muscle weakness can also affect:
People with celiac disease can't eat foods containing gluten, a protein found in wheat, rye, and other grain products. When gluten is in the small intestine, the immune system attacks this part of the GI tract and causes inflammation.
People with celiac disease may experience digestive issues after consuming gluten. Symptoms can include:
According to the National Institute of Diabetes and Digestive and Kidney Diseases, celiac disease affects about 1% of people in the world.
13. Autoimmune vasculitisAutoimmune vasculitis happens when your immune system attacks blood vessels. The inflammation that results narrows your arteries and veins, allowing less blood to flow through them.
14. Pernicious anemiaPernicious anemia may happen when an autoimmune disorder causes your body to not produce enough of a substance called intrinsic factor. Having a deficiency in this substance reduces the amount of vitamin B12 your small intestine absorbs from food. It can cause a low red blood cell count.
Without enough of this vitamin, you'll develop anemia, and your body's ability for proper DNA synthesis will be altered.
It can cause symptoms that include:
This rare autoimmune disease typically occurs in people ages 60 to 70 and older.
What are 5 common symptoms of an autoimmune disorder?Some autoimmune disorders can have similar symptoms at early stages. These can include fatigue, dizziness or lightheadedness, low grade fever, muscle aches, and swelling.
What is the most serious autoimmune disease?Many researchers recognize giant cell myocarditis, a rare autoimmune condition that can lead to heart failure, as one of the most serious autoimmune diseases. It has a 1-year mortality rate of 70%.
What are the most common autoimmune disorders?The most common autoimmune diseases are psoriatic arthritis, rheumatoid arthritis, connective tissue diseases, multiple sclerosis, autoimmune thyroid diseases such as Hashimoto's, celiac disease, and inflammatory bowel disease.
What Is An Autoimmune Disease?
Autoimmune diseases result when your immune system is overactive, causing it to attack and damage your body's own tissues.
Normally, your immune system creates proteins called antibodies that work to protect you against harmful substances such as viruses, cancer cells, and toxins. But with autoimmune disorders, your immune system can't tell the difference between invaders and healthy cells.
Doctors have identified more than 100 different autoimmune diseases, which together affect over 24 million people in the U.S. It's not clear exactly what causes or triggers them. Treatment usually focuses on reducing immune system activity.
Some examples of autoimmune diseases are:
What's the most common autoimmune disease?
Doctors don't agree on which autoimmune disorder is most common. Because there are so many different types, there's no one way that they're reported. Many of them are also hard to diagnose, so people may have them without knowing it. But some of the most common types are type 1 diabetes, MS, RA, lupus, Crohn's disease, and psoriasis.
The exact causes of autoimmune diseases are unknown, but scientists have some theories on what triggers them:
Certain medications. Some drugs may cause changes in your body that confuse your immune system. Talk to your doctor about the side effects of statins, antibiotics, and blood pressure medications in particular.
Genetics. Some autoimmune diseases run in families, so you're at higher risk if your family has a history of them. People who have certain genes may also be more likely to have autoimmune disorders. While genes do play a role, they aren't enough to cause an autoimmune disease on their own.
Infections. Microorganisms like viruses and bacteria could set off changes that make your immune system attack itself. This may be more likely if you're genetically prone to immune system disease.
Certain risk factors raise your chances of getting an autoimmune disorder. Some common ones include:
While signs of autoimmune diseases differ depending on the type and location of the condition you have, some symptoms that are common to many include:
A diagnosis may take time and several different kinds of tests to confirm. The symptoms of many autoimmune diseases look like those of other conditions, so it can take months or even years to get the right diagnosis.
Your doctor may start by interviewing you about your symptoms and health history. Then, they may run some tests commonly used to help diagnose autoimmune disorders.
Blood tests
Your doctor can use different blood tests to cross-check any symptoms you've described. One common test, known as an autoantibody screen, looks for antibodies that are attacking your own tissues (autoantibodies). While the presence of autoantibodies in your blood isn't enough to confirm an autoimmune disease diagnosis, it's a start.
Other blood tests your doctor may use include:
Imaging
Your doctor can use these tests to look for visible signs of an autoimmune disease. For instance, ultrasounds and x-rays can reveal joint issues, and MRIs can show damage deep in your body.
While there aren't any cures for autoimmune diseases yet, there are many kinds of treatment that help control your immune system response and manage your symptoms.
Medication
Your doctor can prescribe different medications depending on the type of autoimmune disorder you have, how serious it is, and what your symptoms are. Some drugs they may use to tamp down an overactive immune reaction include:
Steroids. A group of drugs called corticosteroids are often the first treatment because they work quickly and effectively to lessen your immune system's overactive response. But these slow down your entire immune system, which can come with serious side effects.
Some other drugs focus only on slowing down part of your immune system and come with fewer side effects. These can target cells that make certain antibodies or get rid of specific proteins in your immune system.
Anti-inflammatory drugs. These medications help control your immune system while still supporting organ function. For instance, anti-TNF medications fight tumor necrosis factor (TNF), a protein that spurs inflammation. These are used to treat some forms of autoimmune arthritis and psoriasis. And nonsteroidal anti-inflammatory drugs (NSAIDs) help ease pain, swelling, and stiffness.
Then there are drugs and treatments to help manage symptoms, including:
Your doctor may prescribe medications to supplement substances your body is low on due to your autoimmune disease, such as insulin, thyroid hormone, or vitamin B12.
If the disorder affects your blood, they may also do blood transfusions.
Lifestyle changes
Aside from medications, doctors often suggest shifts in personal habits as part of treatment. Exercise or physical therapy are common for autoimmune diseases that affect your muscles, such as myositis and multiple sclerosis. For those with autoimmune diseases that affect blood vessels, quitting smoking can help.
There are many types of autoimmune diseases, which result when your immune system mistakenly attacks healthy body tissues. Scientists aren't sure why this happens. Most treatments aim to calm your overactive immune system.
What are the 10 most common autoimmune diseases?
While there are more than 100 different kinds of autoimmune disorders, the most common ones include:
What are the most serious autoimmune diseases?
While any autoimmune disease can be hard to manage day to day, there are a few that can be fatal:
Giant cell myocarditis. Though rare, giant cell myocarditis is a life-threatening autoimmune condition that attacks your heart muscle. It has a one-year death rate of 70%.
Mixed connective tissue disease (MCTD). Also rare, this disease has the symptoms of a range of autoimmune diseases such as lupus, scleroderma, and polymyositis. Many people with MCTD also have Sjögren's syndrome, and the disease can lead to serious problems, some of which can be fatal.
What can trigger autoimmune disease?
Typically, one or more triggers in your everyday environment can make your immune system start to attack itself. Some things that can cause an autoimmune disease include:
Is eczema an autoimmune disease?
While your immune system plays a role in eczema, and drugs that suppress your immune system can treat it, it's not technically considered an autoimmune disorder. That's because it doesn't result from an immune system attack on a specific target in your body.
A Lethal Parasite's Secret Weapon: Infecting Non-immune Cells
The organisms that cause visceral leishmaniasis, a potentially deadly version of the parasitic disease that most often affects the skin to cause disfiguring disease, appear to have a secret weapon, new research suggests: They can infect non-immune cells and persist in those uncommon environments.
Researchers found the Leishmania donovani parasites in blood-related stem cells in the bone marrow of chronically infected mice -- precursor cells that can regenerate all types of cells in the blood-forming system. The finding may help explain why some people who develop visceral leishmaniasis, which is fatal if left untreated, often also have blood disorders such as anemia.
Identifying these cells and other unexpected locations in which these parasites live improves scientists' understanding of the disease and may lead to new treatment options, said senior study author Abhay Satoskar, professor of pathology in The Ohio State University College of Medicine.
"Treating a patient with leishmania drugs never eliminates every parasite from the body -- they persist for the rest of a patient's life," Satoskar said. "Perhaps these uncommon cells are the cells responsible for harboring these parasites in low numbers. Some drugs may not reach these cells properly or may not be effective with those parasites, and maybe the parasites in these kinds of cells are different compared to parasites in immune cells because they can adapt. It would be important to eliminate these hidden parasites if we want to stop the transmission of the disease.
"It changes the way we think about this parasite: If uncommon cells are infected, what is the cells' role? What are the parasites doing there? How did they evade the drug treatment? Are they different from parasites in other cells, or the same? There are lots of questions."
The research was published recently in the journal Cell Reports.
Cutaneous leishmaniasis is a disfiguring skin disease caused by Leishmania major parasites that affects up to 1.2 million people annually in the tropics, while L. Donovani parasites cause the less common visceral leishmaniasis that attacks internal organs, affecting an estimated 100,000 people per year. Scientists have suspected L. Donovani may stray beyond their immune cell hosts because they linger in the body, but those suspicions have been difficult to confirm with most conventional technologies because the number of infected cells is low.
Satoskar and colleagues used single-cell RNA sequencing in their search for parasites in spleen and bone marrow cells of chronically infected mice. The technique allowed the team to identify individual cell types based on the thousands of genes expressed by cells that function as a signature of each cell type. Simultaneously, the researchers identified which types of cells were -- and were not -- infected by L. Donovani parasites based on the presence or lack of genes known to be expressed by these organisms.
In the spleen, most of the infected cells detected were frontline immune cells -- macrophages and monocytes -- known as phagocytes whose job is to swallow up invading organisms.
"Textbooks say Leishmania are parasites of immune cells, mainly phagocytes, that hijack those cells and live there. That is what we've learned for many years," said Satoksar, also a professor of microbiology at Ohio State. "Though that was the dogma, it appears during chronic infection that they're also infecting other cell types."
The study showed that these infectious organisms weren't restricted to only phagocytic cells in either organ -- in bone marrow, the blood-related (hematopoietic) stem cells were the main parasitized cells, a surprising finding that was verified through a separate single-cell analysis. The fact their outer surfaces feature some of the same receptors as typical immune cell targets hints at why and how they harbor the parasites, Satoskar said.
Other types of cells in both organs whose gene expression signature suggested they contained L. Donovani parasites included white blood cells that assist the immune system -- but don't engulf infectious organisms -- and cells responsible for the production of platelets.
"Finding Leishmania genes linked to other cell signatures gives us clues of which cells to look for next in follow-up protocols," Satoskar said.
This work has potential for rapid translation to human tissue testing in some tropical regions, where taking needle aspiration spleen and bone marrow samples is a routine procedure for people at risk for leishmaniasis. Such samples could be used to help determine if non-immune cells are occupied by parasites in humans as well.
"These are organs where these parasites persist for many, many years after an infection as cleared and a person who becomes immune suppressed can develop disease again," Satoskar said. "With our animal data and what we find in human samples, we hope to understand the pathways that are assisting parasites to survive and use that knowledge to develop new therapies targeting those pathways."
This work was funded by the Global Health Innovative Technology Fund and the National Institute of Allergy and Infectious Diseases.
Co-authors include Konstantinos Karagiannis, Sreenivas Gannavaram, Thalia Pacheco-Fernandez, Parna Bhattacharya and Hira Nakhasi of the Food and Drug Administration and Chaitenya Verma of Ohio State.
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