Autoimmunity Flashcards
What is autoimmunity and what is an autoimmune disease
Autoimmunity is an immune response against the host due to loss of immunological tolerance of a self antigen
Autoimmune disease is caused by tissue damage or disturbed physiological responses due to an autoimmune mechanism
Name some organ specific autoimmune diseases, their self-antigen and the type of hypersensitivity reaction
Hashimoto’s thyroiditis - thyroid peroxidase and thyroglobulin. Type IV
Type 1 diabetes mellitus - pancreatic islet cels. Type IV
Multiple sclerosis - myelin sheath. Type IV
Goodpasture’s disease - glomeular/alveolar basement membrane. Type II
Addison’s - steroid-21 hydroxylase. Type II-IV
Graves - TSH receptor. Type II
Myasthenia gravis - AChR. Type II
Pernicious anaemia - intrinsic factor. Type II
Name some non-organ specific autoimmune diseases, the self-antigen and the type of hypersensitivity reaction
Autoimmune haemolytic anaemia - RBC antigens. Type II
Rheumatoid arthritis - rheumatoid factor. Type IV
Systemic lupus erythematosus - dsDNA and nuclear proteins. Type III
Sjogren’s syndrome - nuclear antigens. Type IV
What are the two types of autoantibodies
Primary autoantibodies - pathogenic. Present since disease onset and drive the disease
Secondary autoantibodies - found later, during the course of the autoimmune disease
Name some genetic factors that increase risk of an autoimmune disease
Having affected sibling or identical twin
AIRE mutations that affect central tolerance - affect T cell production so have autoimmune T cells being produced
MHC variants are associated with autoimmune disease
Name some environmental factors that increase risk of an autoimmune disease
Hormones
Infection
Drugs
Name some bacteria that are associated with autoimmune conditions
Strep pyogenes M protein - rheumatic fever. Antigen is cardiac muscle
Campylobacter jejuni glycoproteins - Guillain-Barre syndrome. Antigen is myelin-associated gangliosides
Coxsackievirus B4 nuclear proteins - diabetes. Antigen is pancreatic islet cells
Name some drugs that are associated with autoimmune disease
B-penicillamine (RA) - myasthenia gravis, SLE, glomerulonephritis
Methyl-dopa (hypertension) - haemolytic anaemia
SLE is caused by hydralazine (hypertension), procainamide (arrhythmia), isoniazid (TB), minocycline (infection)
What criteria is used in the diagnosis of an autoimmune disease
Presence of autoantibodies/autoreactive T cells
Levels of autoantibodies correlated with disease severity
Autoantibodies/autoreactive T cells found at site of tissue damage
Transfer of autoantibody of autoreactive T cells to a healthy host induces autoimmune disease
Family history
Name some autoimmune diseases that can occur in neonates
Thrombocytopenia
Haemolytic anaemia
Neonatal Grave’s disease
Neonatal myasthenia gravis
Neonatal SLE
What are the treatments of autoimmune diseases
Plasmapheresis
Immunosuppressive drugs - e.g. anti-T cell, anti-proliferative, cytotoxics, anti-metabolites
Anti-inflammatory drugs
Replacement therapy
Surgery
Monoclonal antibodies - Rituximab, Belimumab, Epratuzumab
