Autoimmmune dx Flashcards
Define Systemic Lupus Erythematosis
- Chronic inflammatory autoimmune disorder that affects connective tissue
- Characterized by autoantibodies to nuclear antigens
- Can affect multiple organ systems
- Commonly affects women of child bearing age
- Signs and sx’s vary
A. Severity variable
Mild to life threatening
What are the types of SLE? Who is affected with each type?
- Discoid Lupus - targets the skin
A> Severe inflammation, scarring and rashes on the face, scalp and ears
B> Absence of systemic disease, or may occur in assoc. w/SLE
C. 16.7% progress to SLE w/in 3 yr of Dx - Systemic Lupus Erythematosus - affects organs and joints
- Sub-acute cutaneous lupus – assoc. w/skin lesions
- Drug-induced lupus - due to drug reaction
- Neonatal lupus - affects newborns
What are the rf fro SLE?
- Genetics
- F > M
- Certain medications
A. Procainamide
B. Hydralazine
C. Isoniazid
What is the pathophys of SLE?
- Immune system produces anti-nuclear antibodies
- Ag-Ab complexes form
- Immune complexes become trapped in capillaries of visceral structures
What are the sxs of SLE?
1. Joint sx’s A. Symmetrical arthritis -Earliest manifestation of disease (peripheral joints) 2. Discoid rash A. Raised erythematous patches w/plaques & scales 3. Malar rash A. Characteristic “butterfly rash” B. Present in < 50% pts 4. Oral/nasopharyngeal ulcers 5. Raynaud’s Phenomenon 6. Photosensitivity A. Leg ulcerations 7. Neurologic sx’s A. Seizures, psychosis 8. Cardiopulmonary (Serositis) sx’s A. Pericarditis, endocarditis, murmurs, pleuritis 9. Hematologic manifestations A. Hemolytic anemia, thrombocytopenia, leukopenia, lymphopenia B. Petechiae, pallor 10. Renal manifestations A. Proteinuria, casts 11. Other A. Fever, conjunctivitis, dry eyes, dry mouth
What dx studies are used in SLE?
Combination of blood & urine tests, signs & sx’s, & exam findings leads to Dx ≥ 4 (+) signs/sx’s 1. ESR 2. ANA: screening test 3. Anti–Double Stranded DNA Ab 4. Anti-Smith(Sm) Ab 5. Serum complement 6. CBC w/ diff 7. BUN/Cr, UA 8. CXR 9. Echo
What are the ESR results in SLE?
Usually elevated
What are the ANA results in SLE?
- Indicates a stimulated immune system
- (+) in 95-100% pts
- Not specific
What are the Anti-double stranded DNA Ab results in SLE?
- (+) in 60% pts
2. Used as markers in disease progression
What are the Anti-Smith (Sm) Ab results in SLE?
(+) in 20% pts
What are the serum complement results in SLE?
decreased in 60% pts
Why is a CBC w/ diff used in SLE?
Evaluate for anemia, thrombocytopenia
Why is a BUN/Cr, UA used in SLE?
Evaluate renal function
Why is a CXR used in SLE?
R/O effusions or inflammation
Why is an ECHo used in SLE?
Valve disease (+) in 18% pts
How are the arthralgias and mild serositis in SLE treated?
- NSAIDs
- Hydroxychloroquine sulfate (Plaquenil)
A. Antimalarial -> inhibits phospholipid metabolism & plt aggregation; suppresses immune system
How are the skin symptoms in SLE treated?
- Antimalarial
- Topical corticosteroids, intradermal steroids (discoid)
- Sunscreen
- Immunosuppressive drugs
A. Methotrexate (Trexall)
B. Azathioprine (Imuran)
How is nephritis in SLE treated?
1. Corticosteroids (pulse dose) \+ 2. Cyclophosphamide (Cytoxan) IV monthly THEN 3. Maintain on immunosuppressant A. Mycophenolate mofetil (CellCept) OR B. Azathioprine (Imuran) OR C. Rituximab (Rituxan)
How is the Rapidly progressive renal failure or systemic vasculitis in SLE treated?
Plasmapheresis + Immunosuppressant
How are the CNS sxs of SLE treated?
Corticosteroids, anticonvulsants, antipsychotics
How is anemia and thrombocytopenia in SLE treated?
Corticosteroids
What is the px for SLE?
- 10 year survival rate > 85%
2, Relapsing and remitting course - In some cases, SLE is virulent, leading to severe impairment of lungs, heart, kidneys, brain
- 5X higher risk of MI
- Increased risk of lymphoma, lung CA and cervical CA
- Avascular necrosis of hips/knees
What are the inflammatory myopathies?
- Polymyositis
2. Dermatomyositis
Define polymyositis
1. Idiopathic Dz of striated muscle A. Muscle weakness B. Inflammation C. Muscle fiber breakdown 2. Affects proximal limbs, neck & pharynx 3. Can also affect skin Dermatomyositis A. 25% of these pts will have malignancy 4. Other organ systems affected: Joints, lungs, heart, GI tract 5. Etiology unknown 6. F > M
What are the sxs of polymyositis/dermatomyositis?
1. Insidious onset A. Weeks to months 2. Painless symmetrical proximal muscle weakness A. Neck, shoulders, pelvic girdle 3. Dysphagia & dysphonia 4. Sensation & reflexes preserved 5. Esophageal dysmotility in dermatomyositis 6. Muscle atrophy
What are the sxs of dermatomyositis?
- Erythematous rash on face
- Photosensitivity
- Nail changes
A. Cracking, thickening, periungual telangiectasia - Shawl sign
A. Erythema over neck, shoulders, upper chest & back - Heliotrope rash
A. Periorbital edema with purplish rash of eyelids - Gottron’s papules
A. Violaceous (violet) papules over dorsum of PIP & MCP joints, elbows, knees - Mechanic’s hand
A. Fissured, hyperpigmented, scaly skin
What is the morbidity and mortality of dermatomyositis/polymyositis?
- Resp failure 2° to pulmonary fibrosis
- Cardiac conduction abn w/dermatomyositis
- Systemic autoimmune Dz
A. PM>DM
What are the dx studies for polymyositis/dermatomyositis?
- Lytes, TSH, Ca, Mg
- CK-MM
- muscle bx
- CXR
- Barium Swallow
- EKG
- EMG
What are the CK-MM results in polymyositis/dermatomyositis?
- Up to 50x normal
- ↑ due to muscle inflammation
- ↑ ALT, AST, ANA, Alk Phos, LDH
- +/- ↑RF
- ↑ anti-Jo-1 Ab if interstitial lung Dz
What is the confirmatory test for polymyositis/dermatomyositis?
Muscle bx