Autoimmune disease

Autoimmune disease

Autoimmune disease

Autoimmune diseases are a group of disorders in which the immune system mistakenly attacks the body's own cells and tissues, recognizing them as foreign. This abnormal immune response leads to chronic inflammation, tissue damage, and functional impairment in various organs. There are more than 80 identified autoimmune diseases, each affecting different systems of the body.

Mechanism and Pathophysiology

Under normal conditions, the immune system differentiates between self and non-self cells, targeting harmful invaders such as bacteria and viruses. In autoimmune diseases, this self-tolerance is lost, leading to an attack on the body’s own healthy tissues. This immune dysfunction is often characterized by:

• Activation of autoantibodies – Proteins that mistakenly target the body’s own cells.
• Chronic inflammation – Persistent immune response causing tissue damage.
• Dysregulated T-cell and B-cell function – Leading to excessive immune reactions.
• Cytokine overproduction – Increased inflammatory signals that exacerbate tissue damage.

The specific organs or tissues affected depend on the type of autoimmune disease, with some being systemic (affecting multiple organs) and others being organ-specific.

Types of Autoimmune Diseases

Autoimmune diseases are classified based on the affected organs and systems:

Systemic Autoimmune Diseases

These conditions affect multiple organs and tissues throughout the body:

• Systemic lupus erythematosus (SLE) – Affects the skin, joints, kidneys, and other organs.
• Rheumatoid arthritis (RA) – Targets joints, leading to chronic inflammation and deformity.
• Sjögren’s syndrome – Primarily affects the salivary and tear glands, causing dryness.
• Scleroderma – Causes fibrosis and hardening of connective tissues.
• Vasculitis – Involves inflammation of blood vessels, leading to reduced circulation.

Organ-Specific Autoimmune Diseases

These diseases target specific organs or systems:

• Endocrine System:
• Type 1 diabetes mellitus – The immune system attacks insulin-producing beta cells in the pancreas.
• Hashimoto's thyroiditis – Leads to hypothyroidism due to immune-mediated destruction of the thyroid.
• Graves’ disease – Causes hyperthyroidism by stimulating excessive thyroid hormone production.
• Gastrointestinal System:
• Celiac disease – The immune system reacts to gluten, damaging the small intestine.
• Crohn’s disease and ulcerative colitis – Chronic inflammation of the digestive tract.
• Neurological System:
• Multiple sclerosis (MS) – The immune system attacks the protective myelin sheath around nerve fibers.
• Myasthenia gravis – Antibodies block nerve signals to muscles, leading to weakness.
• Dermatological Conditions:
• Psoriasis – Causes rapid skin cell turnover, leading to scaly patches.
• Vitiligo – Destroys pigment-producing melanocytes, causing skin depigmentation.

Causes and Risk Factors

The exact cause of autoimmune diseases remains unclear, but research suggests a combination of genetic, environmental, and hormonal factors.

• Genetic Predisposition – Family history increases susceptibility.
• Environmental Triggers – Infections, toxins, stress, and dietary factors can initiate immune dysfunction.
• Hormonal Influence – More common in women, suggesting a role of estrogen and other hormones.
• Dysbiosis – Altered gut microbiota may contribute to immune dysregulation.

Symptoms

Autoimmune diseases exhibit a wide range of symptoms depending on the organ system involved. Common symptoms include:

• Chronic fatigue
• Joint pain and stiffness
• Muscle weakness
• Skin rashes
• Gastrointestinal issues
• Neurological disturbances (e.g., numbness, tingling)
• Frequent infections due to immune system imbalance

Diagnosis

Diagnosing autoimmune diseases can be challenging due to overlapping symptoms with other conditions. Physicians use a combination of clinical evaluation and laboratory tests, including:

• Antinuclear antibody (ANA) test – Screens for autoantibodies.
• Rheumatoid factor (RF) and Anti-CCP – Used in rheumatoid arthritis diagnosis.
• Thyroid function tests – Identify autoimmune thyroid disorders.
• Tissue biopsies – Confirm specific autoimmune conditions affecting organs.
• MRI and CT scans – Assess neurological and systemic involvement.

Treatment and Management

While there is no cure for autoimmune diseases, treatments focus on reducing immune system activity, controlling symptoms, and preventing complications.

Common Treatment Approaches

• Immunosuppressive drugs – Reduce immune overactivity (e.g., corticosteroids, methotrexate, azathioprine).
• Nonsteroidal anti-inflammatory drugs (NSAIDs) – Relieve pain and inflammation.
• Biologic therapies – Target specific immune pathways (e.g., TNF inhibitors for rheumatoid arthritis).
• Corticosteroids – Suppress inflammation but require careful long-term use.
• Plasmapheresis – Removes harmful autoantibodies in severe cases.
• Lifestyle modifications – Diet, exercise, and stress management can improve symptoms.

Emerging Research

Ongoing research aims to better understand autoimmune diseases and develop novel therapies, including:

• Precision medicine – Tailoring treatments based on genetic and molecular profiles.
• Stem cell therapy – Investigating regenerative approaches for immune system repair.
• Gut microbiome research – Studying the role of intestinal bacteria in autoimmunity.
• Vaccine-based immune modulation – Developing therapies to retrain the immune system.

See Also

• Autoimmunity
• List of autoimmune diseases
• Chronic inflammatory diseases
• Immunology
• Personalized medicine

Rheumatologic diseases

Arthritis is often used to refer to any disorder that affects the joints. Rheumatic diseases usually affect joints, tendons, ligaments, bones, and muscles. Rheumatologic diseases usually affect joints, tendons, ligaments, bones, and muscles.

Connective Tissue Diseases

Rheumatology and	Connective Tissue Diseases
Ankylosing spondylitis	Arthritis
Arthritis and Rheumatic diseases	Autoimmune diseases
Autoinflammatory diseases	Behçet’s disease
Bursitis	Giant cell arteritis
Gout	Juvenile arthritis
Knee problems	Lupus
Osteoarthritis	Polymyalgia rheumatica
Psoriatic arthritis	Reactive arthritis
Rheumatoid arthritis	Scleroderma
Sjögren’s syndrome	Systemic lupus erythematosus (Lupus)
Tendinitis	Rheumatologic diseases