Systemic lupus erythematosus

M32

DESCRIPTION

Systemic lupus erythematosus (SLE) is a multisystem inflammatory disease characterised by the presence of auto-antibodies directed against various cellular components, particularly DNA. It is often associated with antiphospholipid-antibody-mediated hypercoaguability. In children it predominantly targets the kidneys (in 50–80%), central nervous system, skin and joints.

Treatment of acute lupus depends on severity of illness, with more aggressive treatment for CNS, renal and haematologic involvement.

DIAGNOSTIC CRITERIA

Clinical

Diagnosis may be elusive due to its variations in presentation and is confirmed with at least 4 of 11 criteria:

  1. malar rash: rash over cheeks, sparing nasal folds;
  2. discoid rash: erythematous patches heal with scarring;
  3. photosensitivity: skin rash as a result of unusual reaction to sunlight;
  4. oral or nasopharyngeal ulcers;
  5. non-erosive arthritis: tenderness, swelling or effusion;
  6. pleuro-pericarditis;
  7. renal disease: proteinuria and/or cellular casts;
  8. neurologic disorder: seizures or psychosis in the absence of precipitating circumstances;
  9. haematologic disorder: haemolytic anaemia, leucopaenia, lymphopaenia, thrombocytopaenia;
  10. immunologic disorder:
    1. anti-dsDNA antibody,
    2. anti-Sm (Smith) antibody,
    3. positive antiphospholipid antibodies (anticardiolipin, lupus anticoagulant),
    4. false positive antitreponemal test;
  11. positive anti-nuclear antibody (ANA) test.

Investigations

Note: Normal urine analysis does not exclude renal disease.

  • Urine test strip: haematuria and proteinuria.
  • Urine microscopy: cellular casts.
  • FBC: differential and platelet count.
  • Complement, antinuclear antibodies, anti-dsDNA antibodies.
  • Screen for thyroid involvement.
  • Serum urea, creatinine, electrolytes, albumin and cholesterol.
  • Clotting profile, anti-phospholipid antibody and lupus anti-coagulant.
  • Electrocardiography and chest X-ray.

GENERAL AND SUPPORTIVE MEASURES

  • Counselling, education and a team approach.
  • Adequate rest and appropriate nutrition.
  • Protect from sunlight, sunscreen, hats and avoidance of sunlight if unprotected.
  • Physiotherapy to relieve arthralgia.
  • Psychological support.
  • Immunisation, especially pneumococcal vaccine.
  • Prompt management of infections.
  • Vitamin D and calcium supplementation.

MEDICINE TREATMENT

All children should be treated by a specialist.

All children:

  • Chloroquine (as base), oral, 5 mg/kg/dose once daily.
    • Maximum dose: 150 mg.
    • 6-monthly eye examination necessary.

Chloroquine has a disease-modifying role and is particularly useful for skin and joint disease; some patients can be managed with chloroquine alone or with the addition of low dose steroids.

Induction therapy

The options depend on the severity of the disease and major organ involvement.

For general systemic disease, serositis or musculoskeletal disease:

  • Corticosteroid treatment:
  • Prednisone, oral 2 mg/kg/day; maximum daily dose 60 mg.
    • Reduce dose to 0.5 mg/kg once daily by 2 months

For major organ involvement (severe lupus nephritis class III or IV and neuropsychiatric lupus):

  • Methylprednisolone IVI 30 mg/kg/day (maximum 1000 mg) for 3 days followed by oral prednisone 2 mg/kg/day;
    • Reduce dose to 0.5 mg/kg once daily by 2 months

AND

  • Cyclophosphamide, IV, 500–750 mg/m²/dose, administered over 2 hours
    • Repeat once a month for 6 months.
    • Cyclophosphamide must be given with pre-hydration and continue increased fluid intake for 24 hours after cyclophosphamide infusion,
    • Monitor vital signs during administration of cyclophosphamide.

Maintenance treatment (steroid sparing treatment)

For mild/moderate disease (vasculitic rash, cytopaenia, serositis):

  • Azathioprine, oral, 2–3 mg/kg/dose as single daily dose.
    • Maximum dose: 150 mg.
    • Refer if contraindication to azathioprine or if patient develops adverse effects with treatment.

For musculoskeletal and skin disease:

  • Methotrexate, oral, 10–15 mg/m²/week as a single dose on an empty stomach. Specialist initiated.
    • Maximum dose 25 mg/week.

PLUS

  • Folic acid, oral, 5 mg weekly (on the day after methotrexate) for the duration of the treatment.

REFERRAL

Specialist referral:

  • All patients for confirmation of diagnosis and initiation/supervision of treatment.
  • All patients receiving chloroquine treatment must be referred for ophthalmologic examination.
  • Macrophage activation syndrome.
  • For kidney biopsy if any evidence of renal disease (deteriorating renal function, significant proteinuria/haematuria or hypertension).