Autoimmune Disease

How autoimmune disease develops

The immune system normally learns to tolerate the body's own proteins. In autoimmune disease, that tolerance breaks down. Autoantibodies and immune cells target specific tissues, and inflammation damages them.

Autoimmune diseases are grouped as:

• Organ-specific: one organ is attacked, for example the thyroid in Hashimoto's thyroiditis or the pancreas in type 1 diabetes.
• Systemic: many tissues are affected, as in lupus, rheumatoid arthritis and systemic sclerosis.

What causes autoimmune disease

No single cause is known. It usually reflects a combination of:

• Genes: variants in immune genes such as HLA types. Autoimmune diseases cluster in families, though relatives may have different ones.
• Sex hormones: most autoimmune diseases are far more common in women. Many flare or start around pregnancy, after childbirth or at menopause.
• Infections: viruses such as Epstein-Barr virus may trigger disease in susceptible people, for example in multiple sclerosis.
• Environment: smoking (rheumatoid arthritis, lupus), sunlight (lupus flares), silica dust, certain medicines, and gluten (celiac disease).
• Other autoimmune disease: having one raises the risk of another.

Common autoimmune diseases

Early signs of autoimmune disease

Symptoms vary with the disease, but many share early features:

• persistent fatigue
• joint pain, stiffness or swelling
• muscle aches or weakness
• skin rashes, especially after sun exposure
• low-grade fevers
• hair loss
• numbness or tingling
• dry eyes or dry mouth
• digestive symptoms such as bloating, diarrhea or abdominal pain
• swollen glands
• trouble concentrating

Symptoms often come and go in flares and remissions, which can make diagnosis slow. Keeping a symptom diary with photos of rashes or swollen joints helps your doctor.

Diagnosis

No single test diagnoses all autoimmune diseases. Doctors combine history, examination and targeted tests:

• Antinuclear antibody (ANA): a screening test for systemic autoimmune diseases such as lupus. A positive result is common in healthy people (especially at low levels), so it only means something with matching symptoms.
• Specific antibodies: anti-dsDNA (lupus), rheumatoid factor and anti-CCP (rheumatoid arthritis), TPO antibodies (Hashimoto's), tTG-IgA (celiac disease), acetylcholine receptor antibodies (myasthenia gravis).
• Inflammation markers: ESR and CRP.
• Complete blood count, kidney and liver function, urinalysis.
• Organ-specific tests: thyroid hormones, blood sugar, imaging, biopsies of skin, kidney or gut, nerve studies, MRI.

Depending on the organs involved, you may see a rheumatologist, endocrinologist, gastroenterologist, dermatologist or neurologist.

Treatment

There is no cure for most autoimmune diseases, but treatment aims to control inflammation, prevent damage and relieve symptoms.

• Replacement therapy: insulin for type 1 diabetes, levothyroxine for Hashimoto's, B12 for pernicious anemia, hydrocortisone for Addison's disease.
• Anti-inflammatory medicines: NSAIDs for pain and stiffness.
• Corticosteroids: fast control of flares, used at the lowest dose for the shortest time because of long-term side effects.
• Disease-modifying drugs (DMARDs): methotrexate, hydroxychloroquine, sulfasalazine, azathioprine, mycophenolate.
• Biologics and targeted therapies: TNF inhibitors, IL-17 and IL-23 inhibitors, rituximab, JAK inhibitors and others, which have transformed outcomes in many conditions.
• Diet: strict gluten-free diet for celiac disease.

Immune-suppressing treatment increases the risk of infections. Vaccinations (non-live vaccines) are recommended, and some screening, such as for tuberculosis and hepatitis B, is done before biologics.

Living with autoimmune disease

• Take medicines consistently, even when well, to prevent flares.
• Do not smoke. Smoking worsens rheumatoid arthritis, lupus, Graves' eye disease and Crohn's disease.
• Stay active, with exercise adapted to your condition.
• Protect your skin from the sun if you have lupus or sun-sensitive rashes.
• Plan pregnancies with your specialist, as some medicines need changing.
• Seek support for fatigue, pain and mental health, which are common and treatable.

Frequently asked questions

What are the early signs of autoimmune disease?

Common early signs are persistent fatigue, joint pain or swelling, muscle aches, skin rashes, low-grade fevers, hair loss, numbness, dry eyes or mouth, and digestive problems. Symptoms often come and go. Persistent or recurring symptoms are worth discussing with a doctor.

What causes autoimmune diseases?

They result from a mix of genetic susceptibility and triggers such as infections, hormones, smoking, sunlight and certain medicines. Women are affected much more often, likely because of hormonal and genetic factors. Having one autoimmune disease raises the risk of others.

Is there a test for autoimmune disease?

There is no single test. The ANA blood test screens for several systemic autoimmune diseases, but many healthy people have a positive ANA. Doctors use specific antibody tests, inflammation markers and organ tests based on your symptoms.

Can autoimmune disease be cured?

Most cannot be cured, but many can be controlled very effectively. Some, such as celiac disease, go into remission with diet. Others are managed with hormone replacement or medicines that calm the immune system. Long periods of remission are possible.

Can stress cause autoimmune disease?

Stress alone does not cause autoimmune disease, but major stress and trauma are associated with a higher risk and can trigger flares in people who already have one. Managing stress is a useful part of overall care.