How are Autoimmune diseases classified?
Autoimmune diseases can be classified into two main categories based on the presence or absence of autoantibodies:
1. Organ-Specific Autoimmune Diseases:
These diseases primarily target specific organs or tissues within the body and are characterized by the presence of autoantibodies directed against specific antigens in those organs. Organ-specific autoimmune diseases include:
- Hashimoto's thyroiditis: Autoimmune inflammation of the thyroid gland, leading to an underactive thyroid (hypothyroidism).
- Graves' disease: Autoimmune dysfunction of the thyroid gland, resulting in an overactive thyroid (hyperthyroidism).
- Type 1 diabetes: Autoimmune destruction of islet cells in the pancreas, leading to insufficient insulin production and elevated blood glucose levels.
- Celiac disease: Autoimmune reaction to gluten, causing inflammation and damage to the small intestine.
2. Systemic Autoimmune Diseases:
Systemic autoimmune diseases, also known as connective tissue diseases, affect multiple organs and systems in the body. They are often characterized by the presence of various autoantibodies, some of which have broader reactivity across different tissues. Common systemic autoimmune diseases include:
- Systemic lupus erythematosus (SLE): A chronic inflammatory disorder that can affect various organs, such as joints, skin, kidneys, heart, lungs, and nervous system.
- Rheumatoid arthritis (RA): An inflammatory disease that primarily affects the joints, causing pain, swelling, and stiffness.
- Scleroderma: A group of disorders characterized by hardening and thickening of the skin and involvement of internal organs such as the lungs, kidneys, and gastrointestinal tract.
- Sjögren's syndrome: An autoimmune condition affecting the exocrine glands, particularly the salivary glands and tear glands, leading to dryness in the mouth and eyes.
The classification of autoimmune diseases based on organ specificity or systemic involvement helps guide diagnostic testing, assessment of affected organ systems, and appropriate treatment strategies for managing the specific autoimmune disorder.