ICL 10.0: Autoimmune Diseases Flashcards
what causes autoimmune diseases?
loss of self tolerance
what are the two categories of autoimmune diseases?
- organ specific
2. organ nonspecific
what are organ specific autoimmune diseases?
autoimmunity is directed against a component of a single organ, thus, the resulting clinical symptoms are related to dysfunction of that organ
ex. Hashimoto’s
what are organ nonspecific autoimmne diseases?
autoimmunity directed at antigens that are dispersed in many organs
ex. SLE
what is the pathogenesis of autoimmune diseases?
the pathogenesis involves T cell recognition of specific autoantigen resulting in T and B cell activation and the generation of autoantibodies
autoimmunity in the pancreas causes what?
type I diabetes
autoimmunity in the stomach causes what?
pernicious anemia
autoimmunity in the CNS causes what?
multiple sclerosis
autoimmunity in the thyroid causes what?
Grave’s diseases
Hashimoto’s thyroiditis
autoimmunity in the muscles causes what?
myasthenia gravis
what is pernicious anemia?
results from malabsorption of vitamin B12 that is caused by intrinsic factor deficiency due to one of two mechanisms
B12 has to bind to IF in the stomach in order to be absorbed from the gut into the bloodstream
parietal cells secrete IF
what are the two mechanisms in pernicious anemia that can cause intrinsic factor deficiency?
- progressive autoimmune destruction of parietal cells of the gastric mucosa leading to intrinsic factor deficiency
- the presence of blocking autoantibodies to the intrinsic factor that prevents the formation of vitamin B12-intrinsic factor complex
95% of patients have demonstrable anti-parietal cell antibodies &/or anti-Intrinsic factor antibody
what is the clinical presentation of pernicious anemia?
- low Hb
- unsteady gait, mental changes, confusion, impaired memory, inappropriate behavior
- high MCV
- low B12 levels
what is myesthenia gravis?
an autoimmune disorder that affects the neuromuscular junctions leading to weakness of voluntary muscles with repeated use
the autoantibody involved is anti-ACh receptor antibodies
the autoantibodies target ACh receptors and if ACh can’t bind, then the muscles can’t depolarize and there’s no muscle contraction
which diseases are examples of organ-nonspecific autoimmune diseases?
- Rheumatoid Arthritis (RA)
- Systemic Lupus Erythematosus (SLE)
- Scleroderma, Systemic Sclerosis (SSc)
- Sjögren’s Syndrome (SS)
- Polymyositis/Dermatomyositis (P/DM)
- Vasculitis
- Seronegative spondyloarthropathy
what are constitutional symptoms?
aka systemic symptoms
malaise, low grade fever, and weight loss
what lab results would you see with systemic inflammation?
- elevated RBC sedimentation rate
- elevated C-reactive protein (CRP)
- autoantibodies
what are the two categories of autoantibodies?
- disease nonspecific antibodies
2. disease specific autoantibodies
which autoantibodies are disease non-specific?
antinuclear antibodies (ANA)
rheumatoid factor (RF)
what concentration is a negative titer?
<1:40
what concentration is a low antibody level titer?
1:40 to 1:80
what concentration is an elevated antibody level titer?
> 1:80
what are the 5 titer patterns?
- peripheral/rimmed
- homogenous
- speckled
- centromere
- nucleolar
what antibody and disease is related to a peripheral/rimmed pattern?
antibody: anti-dsDNA
disease: SLE
what antibody and disease is related to a homogenous pattern?
antibody: anti-dsDNA, anti-histone
diseases: RA & SLE
what antibody and disease is related to a speckled pattern?
antibody: SS-A, SS-B, anti-Sm, anti-RNP, anti-Jo-1, anti-Mi-2, anti-Scl-70
diseases: SLE, SSc, PM/DM, Sjogrens
what antibody and disease is related to a centromere pattern?
antibody: anti-centromere
disease: SSc
SSc = Systemic Sclerosis