Diagnostic Criteria and Treatment Options for Systemic Lupus Erythematosus (SLE)
Diagnostic Criteria
SLE diagnosis requires a combination of clinical and laboratory findings, with the 2019 European Alliance of Associations for Rheumatology/American College of Rheumatology classification criteria being 96.1% sensitive and 93.4% specific for SLE. 1
The diagnostic approach includes:
Initial Screening: Anti-nuclear antibodies (ANA) determination by indirect immunofluorescence on Hep-2 cells is the primary screening test 2
- A negative ANA test makes SLE diagnosis unlikely
- ANA should only be obtained in patients with unexplained involvement of two or more organ systems 3
Confirmatory Testing:
- Anti-dsDNA antibodies (highly specific for SLE, associated with renal involvement) 2
- Farr assay is the method of choice for anti-dsDNA; immunofluorescence on Crithidia Luciliae can be used as an alternative 2
- Antibodies to extractable nuclear antigens (ENA) and phospholipids help identify subgroups at risk for specific manifestations 2
- Complement levels (C3, C4) are important for diagnosis and monitoring 4
Neuropsychiatric Evaluation: For patients with neuropsychiatric symptoms, diagnostic workup should include:
- Neuroimaging
- Cerebrospinal fluid analysis
- Electroencephalogram (EEG)
- Neuropsychological tests
- Nerve conduction studies 4
Treatment Options
First-Line Therapy
Hydroxychloroquine should be prescribed to all SLE patients unless contraindicated, as it reduces disease activity, prevents flares, and improves survival. 4, 1
- Dosage: 200-400 mg daily (as a single dose or divided doses) 5
- Regular ophthalmologic monitoring required to detect early retinopathy 4
Treatment Based on Disease Severity
Mild Disease (skin, joints):
Moderate Disease:
Severe Disease (major organ involvement):
- Lupus nephritis (class III/IV): Methylprednisolone pulses followed by oral prednisone with mycophenolate mofetil or cyclophosphamide 4
- Lupus nephritis (class V): Prednisone with mycophenolate mofetil 4
- Neuropsychiatric lupus: High-dose glucocorticoids plus intravenous cyclophosphamide 4
- Belimumab for active SLE and lupus nephritis (more effective in patients with positive anti-dsDNA) 4, 1
Management of Antiphospholipid Syndrome in SLE
- All SLE patients should be screened for antiphospholipid antibodies (aPL) at diagnosis 4
- For SLE patients with high-risk aPL profile, low-dose aspirin is recommended 4
- For thrombotic manifestations:
Disease Monitoring
- Regular assessment of disease activity using validated indices (SLEDAI, BILAG, SLE-DAS) 4
- Monitoring of anti-dsDNA antibodies and complement levels at follow-up visits 4
- Quantitative anti-dsDNA assays (Farr assay or ELISA) are the best methods to monitor disease activity 2
- Evaluation of accumulated damage using SLICC/ACR index 4
Preventive Measures
- Sun protection (UV light avoidance) 4, 7
- Cardiovascular risk factor control (statins and antihypertensives as needed) 6, 4
- Osteoporosis prevention with calcium, vitamin D, and bisphosphonates 4
- Vaccination (inactivated vaccines recommended; live vaccines avoided during immunosuppression) 4
- Lifestyle modifications: regular exercise, smoking cessation, weight control, and stress management 4
Important Considerations
- SLE patients have an almost 5-fold increased risk of death compared with the general population 6
- Common comorbidities include infections, hypertension, coronary heart disease, diabetes mellitus, dyslipidemia, atherosclerosis, osteoporosis, avascular bone necrosis, and certain cancers 6
- Pregnancy considerations: Hydroxychloroquine should not be discontinued during pregnancy; mycophenolate mofetil, cyclophosphamide, and methotrexate must be avoided 4
By following these diagnostic criteria and treatment algorithms, clinicians can effectively manage SLE patients to reduce disease activity, prevent organ damage, and improve quality of life and survival.