Lecture 16: Autoimmune Disorders Flashcards
What causes autoimmunity?
Lymphocytes that recognise self antigens
What is a self antigen?
molecules or proteins that are naturally present in the body’s cells and tissues. These antigens are recognized by the immune system as “self,” which means that they are not foreign or harmful to the body.
What usually prevents autoimmune diseases from developing?
Self tolerance mechanisms
What are the two classes of autoimmunity?
- Organ specific
- Systemic
What are the organ specific autoimmune diseases?
- Type 1 diabetes
- Goodpastures syndrome
- Multiple sclerosis
- Crohns disease
- Psoriasis
- Graves disease
- Hashimotos throiditis
- Autoimmune hemolytic anemia
- Autoimmune addisons disease
- Vitiligo
- Myasthenia gravis
What are the systemic autoimmune diseases?
- Rheuamatoid arthiritis
- Scleroderma
- Systemic lupus erythematosus
- Primary sjogrens syndrome
- Polymyositis
What is rheumatoid arthiritis?
Chronic inflammation and joint damage
What cytokines play a role in rheumatoid arthiritis?
TNF-a
IL-1
IL-6
IL-15
IL-17
What causes rheumatoid arthiritis?
Immune system mistakenly attacks the synovium, which is the lining of the joints, leading to inflammation and damage to the cartilage and bone.
What is the mechanism of tissue damage in rheumatoid arthritis?
antibodies to IgG Fc (“rheumatoid factor”) and citrullinated peptides activate macrophages and promote inflammatory response in the joint
What is the mechanism of tissue damage in rheumatoid arthritis?
antibodies to IgG Fc (“rheumatoid factor”) and citrullinated peptides activate macrophages and promote inflammatory response in the joint
What is the conventional treatment for rheumatoid arthritis?
- Disease modifying antirheumatic drugs (methotrexate; hydroxychloroquine, sulfasalazine)
- Methotrexate
- Anti-inflammatory agents (NSAIDs)
What do DMADs do in rheumatoid arthritis?
Improve symptoms and decrease joint damage
What do NSAIDs do in rheumatoid arthritis?
Reduce pain and stiffness but dont affect long term disease course
What are the biological treatments for rheumatoid arthritis?
- Anti TNF alpha inhibitors e.g., infliximab; etanercept
- Other cytokines e.g., anakinra (IL-1R antagonist)
- Reagents against cell surface molecules: e.g., rituximab (mab against CD20 on B cells); abatacept (CTLA4-Ig fusion protein – binds to CD80/CD86 on antigen presenting cells)
- Targeting signal transduction: e.g. Janus kinases (tofacitnib)
What is Systemic Lupus Erythematosus (SLE)?
Chronic autoimmune disease that can affect multiple organs and tissues in the body, including the skin, joints, kidneys, heart, lungs, and brain.
What are the symptoms of systemic lupus erythematosus?
May include joint pain, rash, fatigue, fever, and sensitivity to sunlight.
What are the mechanisms of tissue damage in systemic lupus erythematosus?
Characterised by high titres of autoantibodies, particularly against nuclear antigens, which generate immune complex-mediated inflammation in the kidneys, skin, joints and cardiovascular system
What are major contributers to mortality caused by systemic lupus erthematosus?
Glomerulonephritis and accelerated atherosclerosis are major contributors