Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by the production of antibodies to components of the cell nucleus in association with a diverse array of clinical manifestations. Because SLE is a disease of unknown aetiology, classification criteria have been devised:
Revised Classification Criteria (1982) for Systemic Lupus Erythematosus
- Malar rash
- Discoid rash
- Oral ulcers
- Arthritis (non-deforming polyarthritis)
- Serositis (pleuritis and/or pericarditis)
- Renal disorder (proteinuria >0.5 g/day or cellular casts)
- Neurologic disorder (psychosis and/or seizures)
- Haematologic disorder (leukopaenia or lymphopaenia/haemolytic anaemia/thrombocytopaenia)
- Immunologic disorder (anti-DNA/anti-Sm/LE cell/false-positive STS)
- Antinuclear antibody
- Diagnosis: four of eleven criteria should be fulfilled at the same time or in succession.
Virtually all organ systems are involved, and the disease is sufficiently complex that two patients may share no clinical findings yet both satisfy criteria for the diagnosis of SLE. Individual patients tend to have a consistent clinical picture and generally accumulate more findings over time. The joints, skin and blood are affected in 80-100% of patients; the kidneys, CNS and cardiopulmonary system in over 50%.