Autoimmune Disorders Flashcards
What causes autoimmune disorders?
Overactive immune system or loss of self tolerance
What is epidemiology of autoimmune disorders.
- Present in about 1% of US popn.
- Most affects women. Classically affects women of childbearing age.
- Most autoimmune diseases are associated with other autoimmune diseases.
What is etiology of autoimmune disorders?
Environment triggers disease in genetically susceptible individuals.
What happens in Lupus?
Lupus is a systemic autoimmune disease in which autoantibodies can cause type II (cytotoxic -
antibody bind and kill cells) or type III hypersensitivity reaction (antigen-antibody complex form and deposit in tissue causing damage).
What are clinical features of lupus?
- Malar ‘butterfly rash’ upon exposure to sunlight is classic sign
- Diffuse proliferative glomerulonephritis commonly occurs; other nephritic/nephrotic symptoms
can occur too. Renal damage is common cause of death - Pleuritis and pericarditis, myocarditis, endocarditis
- Libman-Sacks endocarditis - vegetations on both side of valve
- Antibodies against blood result in - anemia, thrombocytopenia or leukopenia. Infections due to
loss of immune system also a common cause of death. - CNS psychosis due to inflammation of CNS
- Fever and weight loss (fever is sign of inflammation)
- Arthritis
Describe Libman-Sacks endocarditis.
Mostly, endocarditis happens only on one side of valve (up or down). If it happens on both side of
valve, it’s called Libman-Sacks endocarditis and is characteristic of lupus.
What are three common drug that cause lupus? How do we diagnose? How do we treat?
- Hydralizine, procainamide and isoniazid
- Antihistone antibodies are specific for drug induced lupus
- Removal of drug causes remission of disease
What is antiphospholipid syndrome associated with SLE? What lab tests does it affect?
- Antibodies are made against proteins bound to phospholipid.
- Anticardioliptin antibody give false positive syphilis test.
- Lupus anticoagulant antibodies give falsely elevated PTT lab study but makes pt hypercoagulable.
Why do you keep pt with antiphospholipid syndrome on lifelong anticoagulation?
Because lupus anticoagulant antibodies make pt hypercoagulable and increase risk of stroke, DVT,
hepatic vein thrombosis, placental thrombosis (pregnancy loss).
What is sjogren syndrome?
Type IV (lymphocyte mediated) autoimmune destruction of lacrimal and salivary glands with resulting fibrosis.
What are clinical presentation of Sjogren syndrome?
- Dry eyes, dry mouth and recurrent dental carries (bacteria accumulates as teeth aren’t washed) in
older woman. - Parotids may be enlarged due to fibrosis.
- “Can’t chew cracker, dirt in my eyes”
How do you diagnose Sjogren syndrome?
- Presence of ANA is sensitive
- Presence of anti-ribonucleoprotein antibodies is specific - (Anti SSA and anti SSB antibodies -
Sjogren syndrome A and sjogren syndrome B)
What other conditions is Sjogren syndrome associated with?
- Other autoimmune disorders - especially rheumatoid arthritis
- High risk for B-cell lymphoma (HY) - unilateral enlargement of partoid gland late in disease is
indicative of B-cell lymphoma.
What is scleroderma?
Autoimmune tissue damage with activation of fibroblast and deposition of collagen (fibrosis) that
thickens the tissue (also makes it tight and less mobile)
What is diffuse type scleroderma? What are clinical presentation? How do you diagnose?
- Patient has diffuse skin and early visceral organ involvement.
- Esophagus most commonly affected - see solid and liquid dysphagia
- Diagnosis made by ANA and anti-DNA topoisomerase I antibody (aka SCL-70 antibody). SCL stands
for scleroderma.
