Autoimmune disorders Flashcards
What is the prevalence of autoimmune disorders in the USA?
~ 1%
Self-reactive t-cells undergo apoptosis in a process known as what?
Negative selection
- Part of T-cell education
When will T-cells become anergic - through which process?
When it does not receive a second signal
What type(s) of hypersensitivity reaction is SLE?
- Type II (cytotoxic)
- Type III (antigen-antibody complex)
What are the classic features of SLE?
- Fever
- Weight loss
- Malar ‘butterfly’ rash, especially on exposure to sunlight
- Arthritis
- Pleuritis, pericarditis, endocarditis
- CNS psychosis
- Renal damage
- Anemia, thrombocytopenia or leukopenia
What renal damage is the most common injury in SLE?
Diffuse proliferative glomerulonephritis (nephritic syndrome)
What is unique about Libman-Sacks endocarditis?
Vegetations on both sides of heart valve
- Not infectious - inflammatory reaction to deposition of antiG-antiB complexes
How can those with SLE become susceptible to infection?
Antibodies destroy WBCs
What are the 2 main antibodies which cause SLE?
- ANA is sensitive
- Anti-dsDNA is specific
What is the characteristic antiB in drug induced lupus?
Antihistone antibody
What drugs can cause drug-induced lupus?
- Hydralazine
- Procainamide
- Isoniazid
- Methyldopa
- Minocycline
- Phenytoin
- Sulfa drugs
- Etanercept
How would SLE with anti-histone antiBs usually be treated?
Removal of drug
What is anti-phospholipid syndrome due to (what antiBs)?
Autoantibodies against proteins bound to phospholipids
- Anticardiolipin
- Lupus anticoagulant
What percentgae of those with SLE will develop antiphospholipid syndromw?
~ 30%
What antiB can give a false-positive syphilis test in SLE?
Anticardiolipin
What 2 la studies can not be interperted correctly (give false +ves) in antiphospholipid syndrome?
- False positive syphilis test
- Falsely-elevated PTT lab studies
What types of thrombus cab those with anti-phospholipid get?
- DVT
- Budd-chiari
- Placental thrombosis - pregnancy loss
- Stroke
What is budd-chiari syndrome most commonly seen with?
Polycythemia vera
What is Sjogren syndrome a autoimmune destruction of?
Lacrimal and salivary glands
What type of HS reaction is Sjorgen syndrome due to?
Type IV - lymphocyte mediated damage with fibrosis
What is the classic presentation of Sjorgen syndrome?
- Dry eyes
- Dry mouth
- Recurrent dental carries in older woman
What antibodies are associated with Sjorgen syndrome?
What are they called and what do they target?
ANA and anti-ribonucleoprotein antibodies
- Anti-SS-A and anti-SS-B
What is Sjorgen syndrome most commonly associated with?
RA
What cancer are those with Sjorgen syndrome at incrased risk of?
B-cell lymphoma
How will be cell lmmphoma in Sjorgen synrome present?
Unilateral enlargement of parotid late in disease course
- Be wary as those with Sjorgen have bilateral permanent enlargement of the parotids
What is scleroderma?
Autoimmune tissue damage with activation of fibroblasts and deposition of collagen (fibrosis) on tissue
What organs/structures does diffuse scleroderma affect most commonly?
- Skin
- Esophagus - dysphagia due to disordered motility
- Any organ there is early visceral involvement
What antibody characterizes diffuse scleroderma?
- ANA
- Anti-DNA topoisomerase I (Scl-70) antibody
What are the characteristics of localised scleroderma?
Local skin involvement and late visceral involvement
- Calcinosis / anti-Centromere antiBs
- Raynaud phenomenon
- Esophageal dysmotility
- Sclerodactyly (hands fingers)
- Telangiectasias of skin (dialted blood vessels on surface of skin)
CREST
Mixed connective tissue diseasee has characteristics of what other diseases?
- SLE
- Systemic sclerosis
- Polymyositis - proximal muscle disease
What antibodies characteristic mixed connective tissue disease?
Serum antiBs against
- U1 ribonucleoprotein
