Autoimmune

Autoimmune refers to a range of conditions in which the immune system mounts a response against the body's own tissues, leading to inflammation and organ dysfunction. Autoimmunity arises when immune tolerance to self-antigens breaks down, allowing autoreactive B cells and T cells to persist. Autoimmune conditions are often contrasted with autoinflammatory disorders, which involve innate immune pathways with less autoantibody involvement, and with primary immunodeficiencies.

Most autoimmune diseases are chronic and can be organ-specific or systemic. Genetic susceptibility, particularly HLA genes, combines with environmental factors such as infections, smoking, or toxins to trigger autoimmunity in susceptible individuals. Autoantibodies may target hormones, enzymes, structural proteins, or nucleic acids, and autoreactive T cells can mediate tissue damage.

Common organ-specific examples include type 1 diabetes (pancreatic beta cells), Hashimoto's thyroiditis and Graves' disease (thyroid), Addison's disease (adrenal cortex). Systemic autoimmune diseases include rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, psoriasis, celiac disease, and myasthenia gravis.

Diagnosis relies on clinical assessment supported by laboratory tests for autoantibodies and inflammatory markers, imaging, and sometimes tissue biopsy. Treatment aims to reduce immune activity and relieve symptoms, using corticosteroids, disease-modifying antirheumatic drugs, biologic agents targeting specific immune pathways, and symptom-specific therapies. Management also includes lifestyle considerations and management of complications.

The prognosis varies widely by disease and severity. Autoimmune conditions are more common in women and can present at any age. Ongoing research explores tolerance induction, immune regulation, microbiome influences, and tailored therapies to minimize side effects.