Autoimmunity Flashcards
Define autoimmunity
- loss of tolerance to ‘self’
- immune mechanisms destroy healthy tissue
- organ specific - systemic
What is the pathology is associated with autoimmune disease ?
characterised by immune processes causing tissue damage - both cellular & humoral responses
- familial clustering
What are some examples of autoimmune diseases mediated by direct cellular damage ?
- Hashimoto’s - thyroid proteins
- pernicious anaemia - intrinsic factor
- goodpasture’s syndrome - basement membrane
What are some examples of autoimmune diseases mediated by autoantibodies ?
- Graves’ disease = TSH receptor
- Myasthenia gravis = acetylcholine receptor
What are some examples of systemic autoimmune disorders ?
- systemic lupus erythematosus
- multiple sclerosis
- rheumatoid arthritis
Describe the pathology of systemic lupus erythematosus
- Ab to many tissue Ags –> DNA, histones, red cell proteins, platelets
- Ab-Ag interaction causes variety of symptoms - eg fever, weakness, arthritis
Describe the pathology of multiple sclerosis
- inflammatory lesions in CNS result in damage to myelin with subsequent neurological dysfunction
What mechanism support tolerance of self-cells ?
- deletion - self-reactive T cell elimination in thymus & B cell in bone marrow
- Anergy - potentially self reactive cells in peripheral circulation are ‘switched off’
- variation in immunogenicity & sequestration
- immune regulation = antibody network, cytokines & neuroendocrine mechanisms
What are some processes in autoimmunity ?
- Ag processing
- autoantibodies
- cytokines
Describe Ag processing
association of susceptibility with particular MHC alleles & other genetic variation
What are some therapeutic approaches to autoimmunity ?
- conventional immunosuppression
- induction of tolerance
- use of cytokine inhibitors
- treat symptoms
