3. Autoimmunity Flashcards
what are autoimmune diseases driven by?
the presence of auto antibodies or auto reactive T cells resulting in organ fibrosis
also by genetic and environmental factors
what are the risk factors for developing an autoimmune disease?
female
usually post puberty
possible recent infection
define autoimmunity
the immune response against host due to the break in immunological tolerance for self antigens
define autoimmune disease
disease caused by tissue damage or disturbed physiological responses due to an auto immune response
how can an immune disease be subdivided?
organ specific - when the auto antigen is only present on one organic resulting in specific tissue damage
non organ specific - when the auto antigen is found in multiple sites resulting in damage throughout the body - usually type 3 hypersensitivity
how can the disease severity and activity be measured?
correlated to the level of auto reactive T cells/auto antibodies in serology or biopsy (coombs test)
(also depends on organ affected and type of hypersensitivity reaction)
what are the 2 most common auto immune diseases within the UK?
systemic lupus erythematosus
sjogren’s syndrome
what are some types of primary autoantibodies driving disease?
anti TSHR antibodies in Graves’ disease
anti acetylcholine receptor antibodies in myasthenia gravis
anti voltage gated calcium channel antibodies in Lambert-Eaton myasthenia syndrome
anti- anti glomerular basement membrane antibodies in Goodpasture’s syndrome
what are some types of secondary autoantibodies involved in disease (do not drive it, occur later)?
anti nuclear antibodies in SLE
anti gastric parietal cell antibodies in pernicious anaemia
anti thyroid peroxydase antibodies in hashimoto thyroiditis
anti rheumatoid factor antibodies in RA
why do neonates not fully inherit their mother’s autoimmune condition?
so although autoimmune diseases can be transferred, the effect on the neonate diminishes by 6 months when maternal IgE/IgG fades
what treatments are available for autoimmune diseases?
- plasma exchange to remove autoantibodies
- immunosupressive drugs to suppress autoreactive T cells
- anti inflammatory drugs (corticosteroids) to treat tissue damage
- replacement surgery to treat organ dysfunction
- targeted monoclonal antibodies
what is autoimmune rheumatic disease?
results from a break in immune tolerance by producing pathogenic antibodies which result in a group of diseases which affect multiple systems
how can the severity of ARD’s be defined?
presence of autoantibodies
clinical features
what approach should be used in taking a history for ARD’S (lupus)
constitutional symptoms - fever, fatigue, weight loss, night sweats, poor appetite 'Glove and sweater' glove - Raynauds Joint pains and swelling Hand rash sweater - Proximal muscle weakness > Myalgia Hair loss Eye and mouth dryness Nose bleeds Mouth ulcers Pleuritic chest pain Pericardial pain Truncal Rash/Photosensitivity Limb weakness
what might be found on a clinical examination in someone with ARD’s?
ulcers, muscle weakness, alopecia, rash
