About Systemic Lupus Erythematosus (SLE)

System lupus erythematosus (SLE) is a chronic multisystemic autoimmune disease.

  • Autoantibodies deposit within tissues and fix complement
  • Multifactorial etiology: Interplay between genetic, environmental, and hormonal factors
  • Predominantly affects young women in childbearing years
  • Peak age of onset: 15 – 45 y.o.
  • Racial and gender disparities exist in terms of organ involvement, disease severity and response to therapy
  • Reported worldwide prevalence frequencies range from 20 to 240 per 100,000 people
  • Reported worldwide incidence rates range from 1 to 10 per 100,000 person-years

Disease Overview & Diagnostic Workup

  • Lupus is a complex multisystemic disease.
  • Diagnosis is made clinically based on symptoms and signs.
  • Use laboratory data to confirm the diagnosis.
  • ANA is a hallmark of lupus but it is not specific for lupus.
  • Sun exposure can precipitate flares of lupus.
  • Preventative health measures should be taken to prevent disease flares and complications.

Treatment

  • Hydroxychloroquine is recommended for all patients with lupus.
  • Choice of immunosuppressive therapies depends on organ involvement.

Heterogeneous disease

Cutaneous

  • Alopecia
  • Photosensitive rashes
  • Discoid rash

Musculoskeletal

  •  Arthralgias
  • Jaccoud’s arthropathy

Ocular

  • Periorbital swelling
  • Retinal vasculitis

Serositis

  • Pericarditis
  • Pleuritis

Cardiovascular

  • Libman-Sacks endocarditis

Renal

  • Nephritis

Hematologic

  • Leukopenia
  • Anemia
  • Thrombocytopenia

Neurologic

  • Seizures
  • Psychosis
  • Cerebrovascular accidents
SLE is diagnosed clinically using a combination of clinical features and supporting labs.

Lab Workup

  • Antinuclear antibodies (ANA)
    • Laboratory hallmark of SLE
    • >98% of SLE patients have a positive ANA. However, ANA is not specific for SLE (up to 33% of healthy adult  population has a +ANA but only ~ 5% will develop SLE).
    • Other antibodies: anti-dsDNA, anti-Smith, SSA (anti-Ro), SSB (anti-La), antiphospholipid antibodies
  • CBC, CMP, urinalysis, UPC, complement levels

Imaging & Biopsy

  • Imaging studies and renal biopsy might be required

Differential diagnosis is broad.

  • Other connective tissue diseases
    • Scleroderma
    • Sjogren’s
    • Mixed connective tissue disease
  • Systemic vasculitis
  • Sarcoidosis
  • Lymphoma
  • Infective endocarditis
  • Viral infections (EBV, hepatitis C, HIV, etc.)

Sun Avoidance

  • UV light exposure can exacerbate cutaneous rashes & cause flares)
  • Patients should wear protective clothing & use sunscreen regularly

Pharmacotherapy

  • Pharmacotherapy choice is based on organ involvement
  • Hydroxychloroquine:
    • Best long-term Rx 
    • Recommended for all patients with systemic lupus
  • NSAIDs: Can be used for arthralgias
  • Local or systemic glucocorticoids: for acute exacerbations
  • Immunosuppressive agents (e.g., mycophenolate, azathioprine, cyclophosphamide, belimumab, etc.)
    • For organ threatening manifestations such as glomerulonephritis
    • Used a steroid-sparing agents
  • Disease activity measures:
    • SLEDAI
    • BILAG
  • Encourage regular clinical and lab monitoring by a rheumatologist
  • Lupus is an independent risk factor for cardiovascular disease
    • Emphasize smoking cessation
    • Manage BP, lipids
    • Screen for diabetes
    • Encourage maintenance of healthy weight
  • Slightly higher risk of overall cancer development due to lupus
    • Emphasize need for malignancy screening
  • Discuss reproductive health
  • Assess bone health
    • Risk of vitamin D deficiency due to sun avoidance and decreased bone density from glucocorticoid use and inflammation