12- SLE

• Autoimmune disorder


  Characterized by exacerbations and remissions, leading to inflammation and tissue damage involving multiple organs systems
• Women account for 90% of cases, more frequently African American
• Etiology


  • Genetic
  • Environmental
  • Drug-induced
• Genetic factors


  • HLA-DR2, HLA-DR3, HLA-B8
  • Low complement gene C1q C2 C4
• Environmental factors


  • Exposure to EBV
  • UV light exposure
  • Hormonal factors: estrogen
• Drug-induced factors


  • hydralazine, isoniazid, procainamide, penicillamine
• Most common initial findings


  • Malar rash
  • Joint pain
  • Fatigue
• Constitutional symptoms


  • Fatigue
  • Malaise
  • Fever
  • Weight loss
• Multiple organ involvement leads to many manifestations
• Diagnosis of SLE


  Based on the presence of at least 4 of 11 manifestations
• Skin manifestations


  • Malar rash
  • Discoid rash
  • Photosensitivity
  • Oral or nasopharyngeal ulcers
• Joint manifestations


  • Arthritis (inflammatory and symmetrical but not erosive)
  • Arthralgia
• Chest manifestations


  • Serositis: pleuritis or pericarditis (chest pain +/- pericardial/pleural effusion)
• Renal manifestations


  • Glomerulonephritis
  • Proteinuria
  • Hematuria
  • Azotemia
  • ESRD
• Neurological manifestations


  • Psychosis
  • Seizures
  • Stroke
  • Headaches
• Hematological manifestations


  • Hemolytic anemia
  • Leukopenia
  • Lymphopenia
  • Thrombocytopenia
• Anemia of chronic disease is a more common presentation, but it is not part of the diagnostic criteria
• Immunological manifestations


  • Positive ANA
  • Positive anti-dsDNA or anti-Sm
  • False +ve test for syphilis
• Libman-Sacks endocarditis


  • Sterile vegetations
• Myocarditis


  May lead to arrhythmias
• Accelerated atherosclerosis
• Thrombosis (both arterial & venous)


  Must rule out pulmonary embolism in any SLE pt with acute SOB
• Other manifestations of SLE (but not part of diagnostic criteria)


  • Libman-Sacks endocarditis (sterile vegetations)
  • Myocarditis (may à arrhythmias)
  • Accelerated atherosclerosis
  • Thrombosis (both arterial & venous) à must rule out pulmonary embolism in any SLE pt with acute SOB
  • Pneumonitis (may lead to fibrosis)
  • Cranial nerve lesions, polyneuropathy, aseptic meningitis
  • Mesenteric vasculitis, vasculitic lesions of fingertips and nail folds
  • Raynaud's phenomenon (vasospasm of small vessels when exposed to cold)
  • Antiphospholipid syndrome
  • Aseptic necrosis of the hip/knee
  • Alopecia, urticaria, purpura
  • Photophobia, retinal lesions (cotton-wool spots), blindness
• Most common cause of death in young pts is infection, and in old patients is accelerated atherosclerosis à MI
• Positive ANA screening tests


  • Very sensitive but not specific
• Anti-dsDNA (60%) and Anti-Sm (30%) Ab


  Presence is diagnostic, specific
• Antibodies found in 15% to 35%


  • Ro (SS-A)
  • La (SS-B)
• Ro (SS-A) and La (SS-B)


  • More often found in Sjogren syndrome
  • Anti-Ro in pregnant mother's blood increases risk of neonatal SLE and heart block, check baby ECG
• Ribosomal P


  Marker for cerebral lupus
• Antihistone Abs


  Marker for drug-induced lupus
• Complement levels


  • Decreased C3 and C4
• Inflammatory markers


  • High ESR
• Markers of disease activity (acute flare)


  • Drop in complement level C3 C4
  • Rise in anti-dsDNA levels
• Increased ESR/CRP is NOT a marker of disease activity. If higher inflammatory markers than baseline, look for infection
• Treatment


  1. Avoid sun exposure

  2. Control of cardiovascular risk factors
• NSAIDs


  For arthralgia and less severe symptoms
• Acute flare treatment


  High-dose boluses of steroids
• Long-term therapy


  • Antimalarial agents such as hydroxychloroquine (Plaquenil)
  • Best long-term therapy for mild chronic disease limited to skin & joints
  • Annual eye examination is needed because of retinal toxicity
• Belimumab


  1. lymphocyte stimulator monoclonal Ab. Inhibits B-cell activating factor. Controls progression of SLE.
• Lupus nephritis treatment


  1. Steroids + cyclophosphamide

  2. Need kidney biopsy

  3. Care of nephrologist