Rheumatology Book

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Systemic Lupus ErythematosusAka: Lupus, SLE

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  1. See Also
    1. Cutaneous Lupus Erythematosus
  2. Background
    1. Named in 1851 for wolf (lupus) bite-like facial rash
  3. Epidemiology
    1. Prevalence
      1. U.S.: 40 to 50 per 100,000 persons
      2. England: 200 per 100,000 women aged 18 to 65 years
    2. Over-diagnosed in United States
      1. Of 2 million U.S. cases, only 25% have true disease
    3. Age distribution
      1. Young adults with onset 15-64 years
      2. Children comprise 10-15% of cases
    4. More common in women by ratio of 9:1
    5. Ethnic predisposition
      1. Native American
      2. African American
      3. Hispanic
      4. Chinese
      5. Filipino
  4. Etiology
    1. Idiopathic
    2. Drug Induced
      1. Procainamide
      2. Isoniazid
      3. Hydralazine
      4. Minocycline
      5. Phenytoin
      6. Ethosuximide
      7. D-Penicillamine
  5. Pathophysiology
    1. Tissue damage by antibody and immune complex deposition
    2. Autoantibodies form to cell nucleus components
  6. Symptoms
    1. Fatigue
    2. Fever
    3. Malaise
    4. Weight loss
  7. Signs: General
    1. Dermatologic
      1. See Cutaneous Lupus Erythematosus
      2. Malar "butterfly" rash
      3. Photosensitivity
      4. Vasculitis
      5. Alopecia
      6. Oral Ulcers
      7. Sicca Syndrome
    2. Rheumatologic
      1. Arthritis
      2. Myositis
    3. Abdominal
      1. Lymphadenopathy
      2. Splenomegaly
      3. Nephritis
      4. Mesenteric Vasculitis
    4. Neuropsychiatric
      1. Organic brain syndrome
      2. Seizures
      3. Psychosis
    5. Cardiopulmonary
      1. Pleuritis
      2. Pericarditis
      3. Myocarditis
      4. Pneumonitis
      5. Arterial thrombosis
      6. Venous thrombosis (DVT)
    6. Ocular changes (20% of SLE cases)
      1. Eye disorders
        1. Keratoconjunctivitis Sicca
        2. Uveitis
        3. Episcleritis and Scleritis
        4. Keratitis
        5. Blepharitis-like Discoid Lupus eyebrow involvement
      2. Neurologic conditions
        1. Optic Neuritis
        2. Ischemic Optic Neuropathy
        3. Amaurosis Fugax
      3. Retinal disorders
        1. Cotton wool spots
        2. Retinal hemorrhages
        3. Proliferative retinopathy
  8. Signs: Children
    1. Fever
    2. Malar Rash
    3. Arthritis
    4. Alopecia
    5. Anemia
    6. Leukocytopenia
    7. Renal involvement
  9. Diagnosis: ACR requires 4 of 11 criteria
    1. Malar Rash
    2. Discoid rash
    3. Photosensitivity
    4. Oral Ulcers
    5. Polyarthritis involving more than 2 joints
    6. Pleuritis or Pericarditis
    7. Antinuclear Antibody titer positive (1:40 or higher)
      1. Titer over 1:320 is very suggestive
    8. Renal disease
    9. Neurologic disorder (e.g. Seizures, Psychosis)
    10. Anemia, Neutropenia or Thrombocytopenia
    11. Anti-dsDNA, Anti-Sm positive, Syphilis False Positive
  10. Labs: Protocol
    1. Lab interpretation described specifically below
    2. Indications for ANA titer
      1. Unexplained involvement of Two or more organ systems
      2. ANA is very prevalent in normal population
    3. Initial Screening
      1. ANA titer positive if 1:40 dilution or higher
    4. Secondary testing if ANA titer positive
      1. Complete Blood Count
      2. Urinalysis
      3. Serum Creatinine
      4. Antiphospholipid Antibody
      5. Double Stranded DNA Antibody (Anti-dsDNA)
      6. Smith Antibody (Anti-Smith or Anti-Sm)
  11. Labs: Interpretation
    1. Complete Blood Count
      1. Anemia
      2. Neutropenia
      3. Thrombocytopenia
    2. Erythrocyte Sedimentation Rate elevated
    3. Electrocardiogram
    4. Urinalysis
      1. Consider 24 Hour Urine Protein
      2. Consider Creatinine Clearance
    5. Antinuclear Antibodies
      1. Antinuclear Antigen (ANA)
        1. Positive in 98% of true SLE cases
        2. Only 5% of ANA positive patients have SLE
      2. Smith Antibody (Anti-Smith or Anti-Sm)
        1. Positive in 20-30% of SLE cases
        2. Highly specific for SLE
      3. Anti-ribosomal P (Lupus sensitivity: 20-30%)
        1. Highly specific for lupus erythematosus
        2. Associated with Lupus Psychosis
      4. Double Stranded DNA Antibody (Anti-dsDNA)
        1. Positive in 60-70% of SLE cases
        2. Specific for lupus erythematosus
        3. Associated with Lupus Nephritis
        4. Associated with Lupus CNS Involvement
      5. Anti-Ro (Anti-SSA)
        1. Positive in 40% of SLE cases
      6. Anti-La (Anti-SSB)
        1. Positive in 10-15% of SLE cases
      7. Histone Antibody (Anti-histone)
        1. Positive in 50-70% of SLE cases
    6. Complement Levels
      1. Complement C3
      2. Complement C4
      3. Complement CH50
    7. Syphilis Serology (VDRL or RPR)
    8. Coagulation Factors
      1. Prothrombin Time
      2. Partial Thromboplastin Time (PTT)
  12. Associated Conditions
    1. Hyposplenism
  13. Management: General Principles
    1. Reevaluate every 3-6 months
    2. Employ measures to relieve Fatigue
    3. Sunscreen and other protection due to photosensitivity
    4. Reduce risk of infection (e.g. Immunizations)
    5. Birth Control is critical during exacerbations
  14. Management: Medications
    1. Salicylates and NSAIDs
      1. Enteric Coated ASA 650 mg PO every 4-6 hours prn
      2. Ibuprofen 400-800 mg PO tid-qid prn
    2. Anti-Malarial agents
      1. Hydroxychloroquine (Plaquenil) 400 mg/day
    3. Corticosteroids
      1. Topical Corticosteroids
      2. Intralesional Corticosteroids
      3. Systemic Corticosteroids in severe exacerbations
        1. Prednisone 0.5 to 1 mg/kg/day up to 4 weeks or
        2. Solu-medrol 15 mg/kg IV for 3 days
    4. Cytotoxic agents
      1. Cyclophosphamide
        1. Daily dosing: 1.5-2.5 mg/kg/day or
        2. Monthly dosing: 10-15 mg/kg IV every 4 weeks
      2. Azathioprine 2-3 mg/kg/day
    5. Additional measures
      1. Ophthalmology consultation for dilated eye exam
        1. Initial exam on starting steroids or Plaquenil
        2. Repeat exam yearly in high risk patients
  15. Prognosis
    1. Overall five year survival: 91-97%
    2. Worse prognostic factors
      1. Seizure disorder
      2. Lupus Nephritis
      3. Azotemia
      4. Onset in childhood
  16. Resources
    1. American Lupus Society (Ventura, CA)
      1. Phone: (800) 331-1802
    2. Lupus Foundation of America
      1. http://www.lupus.org/lupus
  17. References
    1. Edworthy in Ruddy (2001) Kelly's Rheumatology, 1105-19
    2. Sercombe in Marx (2002) Rosen's Emergency, p. 1607-13
    3. Gill (2003) Am Fam Physician 68:2179

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