Systemic Lupus Erythematosus

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 a very small percentage will develop SLE).
  • Other antibodies: anti-dsDNA, anti-Smith, SSA (anti-Ro), SSB (anti-La), anti-RNP, antiphospholipid antibodies
• CBC with differential, CMP, urinalysis, urine protein: creatinine ratio, complement levels

Imaging & Biopsy

• Imaging studies and renal biopsy may be required to evaluate for certain clinical manifestations (e.g. CXR for pleural effusion, kidney biopsy for renal involvement)

Differential diagnosis is broad.

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

Sun Avoidance

• UV light exposure can exacerbate cutaneous rashes and cause flares.
• Patients should wear protective clothing, use sunscreen regularly, and minimize sun exposure during peak UV hours.

Pharmacotherapy

• Pharmacotherapy choice is based on organ involvement, although all patients should be initiated on hydroxychloroquine.
• The most severe organ manifestation (e.g. CNS or kidney involvement) will often dictate treatment.

General SLE Meds

• Anifrolumab
• Azathioprine
• Belimumab
• Cyclophosphamide
  • Typically reserved for severe manifestations, such as CNS or kidney
• Hydroxychloroquine:
  • Staple of lupus treatment
  • Shown to modify disease progression in SLE and to prevent flares
  • Recommended for all patients with systemic lupus
• Methotrexate
• Mycophenolate
• Local or systemic glucocorticoids for acute exacerbations

Lupus Nephritis Therapies

• Systemic steroids
• Azathioprine, PO
• Belimumab
• Cyclophosphamide
• Mycophenolate, PO BID
• Calcineurin inhibitors:
  • Tacrolimus
  • Voclosporin

• Disease activity measures:
  • Systemic Lupus Erythematosus Disease Activity Index (SLEDAI-2K)
• Goal is remission or low lupus disease activity
• Encourage regular clinical and lab monitoring by a rheumatologist
  • Routine labs include CBC with differential, C3/C4, dsDNA, Cr, urinalysis with microscopic urine protein:creatinine
• Lupus is an independent risk factor for cardiovascular disease.
  • Emphasize smoking cessation
  • Manage BP, lipids using diabetes thresholds
  • Screen for diabetes
  • Encourage maintenance of healthy weight
• Slightly higher risk of overall cancer development
  • Emphasize need for malignancy screening, especially cervical and colorectal cancer
• Discuss reproductive health
• Assess bone health
  • Risk of vitamin D deficiency due to sun avoidance and decreased bone density from glucocorticoid use and inflammation
• Assess mental health
  • Anxiety and depression is commonly seen in patients with lupus.
  • Evaluate chronic pain when present and discuss interventions

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 is not specific for lupus.
• Sun exposure can precipitate flares of lupus.
• Malar rash that spares the nasolabial fold is the most common lupus rash.
• Preventative health measures should be taken to prevent disease flares and complications.

Treatment

• Hydroxychloroquine is recommended for all patients with lupus.
  • Dose is weight based
  • Improves mortality
  • Retinal screening recommended for long-term use of HCQ
• Choice of immunosuppressive therapies depends on organ involvement.
• Acute flares are often treated with a steroid taper, the length of which depends on the clinical manifestation(s).