Autoimmunity Flashcards
What is autoimmunity?
Immune response against the host due to the loss of immunological tolerance of self antigens
What is an autoimmune disease?
Disease caused by tissue damage or disturbed physiological responses due to an autoimmune response
How can autoimmune diseases be classified?
Organ specific
Non-organ specific
What are some organ specific diseases?
T1DM
MS
Graves disease
Hashimoto’s disease
What are some non-organ specific diseases?
Autoimmune haemolytic anaemia
RA
Sjogren’s syndrome
SLE
How can hypersensitivity reactions in autoimmunity be divided?
Autoantibody driven
- complement activation
- antibody-mediated cell cytotoxicity
- neutrophil activation
Autoreactive T cell driven
- cytotoxic T cells
- macrophages
What are the diagnostic criteria?
- Presence of autoantibodies/autoreactive T cells
- Levels of autoantibodies correlate with disease severity
- Autoantibodies/autoreactive T cells found at site of tissue damage
- Transfer of autoantibody/autoreactive T cell into a healthy host induces disease
- Clinical benefit from immunomodulatory therapy
- Family history
What are primary autoantibodies?
Present at the beginning of the disease
What are examples of primary autoantibodies?
Anti-TSHR - Graves
Anti-acetylcholine receptor - Myasthenia Gravis
What are secondary autoantibodies?
Appear later in the disease
What are examples of secondary autoantibodies?
ANA - SLE
Anti-TPO - hashimoto’s
What are the mechanisms of induction of autoimmunity?
Breakdown of central tolerance
- failure to delete autoreactive T cells
Breakdown of peripheral tolerance
- regulatory T cell defects
- impaired immunomodulation
- altered self antigens
Activation of autoreactive B cells
- T cell independent activation of B cells
- carrier effect
What can trigger autoimmunity?
Genetic factors
Hormones
Infections
Drugs
How can autoimmune diseases be managed?
Monoclonal antibodies Plasma exchange Immunosuppression Anti-inflammatory drugs Replacement therapy
