Autoimmune Diseases Overview

Autoimmune Diseases

Definition

• Autoimmune diseases occur when the immune system fails to distinguish between self and non-self, leading to an immune response against the body's own cells, tissues, and organs.

Characteristics

• Chronic inflammation
• Tissue damage
• Loss of organ function
• Genetic predisposition

Types of Autoimmune Diseases

• Organ-specific:
  • Type 1 diabetes (pancreas)
  • Hashimoto's thyroiditis (thyroid gland)
  • Graves' disease (thyroid gland)
  • Pernicious anemia (stomach)
• Non-organ specific:
  • Rheumatoid arthritis (joints)
  • Lupus (multiple organs)
  • Sjögren's syndrome (exocrine glands)
  • Multiple sclerosis (central nervous system)

Causes and Triggers

• Genetic factors: genetic predisposition, gene-environment interactions
• Environmental factors: infections, toxins, stress, hormonal imbalances
• Immunological factors: immune system dysregulation, T cell or B cell abnormalities

Pathogenesis

• Activation of autoreactive T cells: T cells that recognize self-antigens
• Production of autoantibodies: B cells produce antibodies against self-antigens
• Cytokine imbalance: pro-inflammatory cytokines dominate anti-inflammatory cytokines
• Inflammation and tissue damage: immune response leads to tissue damage and organ dysfunction

Diagnosis and Treatment

• Diagnosis: combination of clinical features, laboratory tests, and imaging studies
• Treatment: depends on the specific disease, may include:
  • Immunosuppressive drugs
  • Corticosteroids
  • Biological therapies (e.g., anti-TNF agents)
  • Plasmapheresis
  • Organ transplantation

Autoimmune Diseases

Definition

• Occur when the immune system fails to distinguish between self and non-self, leading to an immune response against the body's own cells, tissues, and organs.

Characteristics

• Chronic inflammation is a hallmark of autoimmune diseases.
• Tissue damage and loss of organ function are common consequences.
• Genetic predisposition plays a significant role in autoimmune diseases.

Types of Autoimmune Diseases

Organ-Specific Diseases

• Type 1 diabetes targets the pancreas.
• Hashimoto's thyroiditis and Graves' disease affect the thyroid gland.
• Pernicious anemia affects the stomach.

Non-Organ Specific Diseases

• Rheumatoid arthritis affects the joints.
• Lupus can affect multiple organs.
• Sjögren's syndrome targets exocrine glands.
• Multiple sclerosis affects the central nervous system.

Causes and Triggers

• Genetic factors contribute to autoimmune diseases through genetic predisposition and gene-environment interactions.
• Environmental factors, such as infections, toxins, stress, and hormonal imbalances, can trigger autoimmune diseases.
• Immunological factors, including immune system dysregulation and T cell or B cell abnormalities, can lead to autoimmune diseases.

Pathogenesis

• Autoreactive T cells are activated, recognizing self-antigens as foreign.
• B cells produce autoantibodies against self-antigens.
• Cytokine imbalance leads to a pro-inflammatory response, causing tissue damage.
• Inflammation and tissue damage ultimately result in organ dysfunction.

Diagnosis and Treatment

• Diagnosis involves a combination of clinical features, laboratory tests, and imaging studies.
• Treatment options vary depending on the specific disease, but may include:
  • Immunosuppressive drugs to reduce the immune response.
  • Corticosteroids to reduce inflammation.
  • Biological therapies, such as anti-TNF agents, to target specific inflammatory pathways.
  • Plasmapheresis to remove autoantibodies from the blood.
  • Organ transplantation in severe cases.