Flashcards in Ch 4: Autoimmune High Yield Deck (27):
How do autoimmune disorders arise? Principles of immunology
Loss of self-tolerance
1) self-reactive lymphocytes do not undergo apoptosis in thymus or bone marrow (no negative selection)
2) self-reactive lymphocytes become anergic
How do lymphocytes become anergic?
recognition of antigen in peripheral lympoid tissues w/o 2nd signal
What is a common etiology of autoimmune disorders?
environmental trigger in genetically susceptible individuals
Which two types of hypersensitivity reactions damage multiple tissues in the host for SLE?
Type II (cytotoxic) = direct damage to tissue
Type III (antigen-Ab complex)
What are the clinical features of SLE?
fever and weight lose
malar “butterfly” rash, esp w/sunlight exposure
pleuritis and pericarditis (serosal surfaces)
What is the most common injury to kidneys in SLE?
diffuse proliferative glomerulonephritis
What is Libman-Sacks endocarditis?
SLE classic finding
small sterile deposits/vegetations on both sides of mitral valve, not infectious
What 2 autoantibodies characterize SLE?
1) antinuclear antibody (ANA)...Sm antigen (spliceosome)
2) anti-dsDNA antibody
Which autoantibody is sensitive but not specific for SLE?
Which autoantibody is highly specific for SLE?
Which autoantibody is charcteristic of drug-induced SLE?
What 3 drugs can cause drug induced SLE?
Hydralazine, procainamide, isoniazid
What is Antiphospholipid antibody syndrome?
Associated with SLE
Autoantibodies to proteins bound to phospholipids
Anticardiolipin & Lupus anticoagulant
Result: arterial/venous thrombosis, DVT, Budd-Chiari (hepatic vein thrombosis), placental thrombosis, stroke
Requires lifelong anticoagulation
What could lead to a false + syphilius test and falsely elevated pTT labs, respectively?
anticardiolipin and lupus anticoagulant autoantibodies
What is Sjogren Syndrome?
Autoimmune destruction of lacrimal and salivary glands
What are the clinical features of Sjogren Syndrome?
keratoconjunctivitis (dry eyes)
xerostomia (dry mouth)
may be associated with RA
Which hypersensitivity rxn is associated with Sjogren Syndrome?
Type IV Hypersensitivity
lymphocyte-mediated damage with fibrosis
Which autoantibodies are associated with Sjogrens Syndrome?
ANA (antinuclear antibody)
anti-ribonucleoprotein antibodies ( anti-SS-A/ro and anti-SS-B/la)
What other disease are ppl with Sjogrens Syndrome at risk to develop?
presents as unilateral enlargement of parotid gland
What is scleroderma?
Activation of fibroblasts and deposition of collagen (fibrosis)
What is localized scleroderma? Which autoantibody is it associated with?
involves only skin, anti-DNA topoisomerase II antibody
What is systemic scleroderma?
involves skin and other visceral organs
What is limited type systemic scleroderma?
limited areas of skin (hands, face, neck) with late visceral involvement
What is CREST syndrome? Each letter of CREST?
Limited type systemic scleroderma, late visceral involvement
C = Calcinosis/anti-Centromere antibodies
R = Raynaud Phenomenon
E = Esophageal dysmotility >> dysphagia
S = Sclerodactyly
T = Telangiectasias of skin (small vessels dilated)
What is diffuse type systemic scleroderma?
skin and any visceral organ (GI, lungs, kidneys)
What is mixed connective tissue disease (MCTD)?
Autoimmune-mediated damage with mixed features of SLE, systemic scleroderma, and polymyositis