From the Guidelines
The best approach to evaluate a patient for systemic lupus erythematosus (SLE) involves a comprehensive assessment combining clinical examination, laboratory testing, and application of classification criteria, with a focus on disease activity, organ damage, and quality of life, as recommended by the European League Against Rheumatism (EULAR) 1.
Key Components of Evaluation
- A thorough history and physical examination focusing on characteristic manifestations such as malar rash, photosensitivity, oral ulcers, arthritis, serositis, renal disorder, neurologic disorder, hematologic abnormalities, and constitutional symptoms like fatigue and fever.
- Laboratory evaluation including complete blood count, comprehensive metabolic panel, urinalysis, and specific autoantibody tests including antinuclear antibody (ANA), anti-double-stranded DNA (anti-dsDNA), anti-Smith (anti-Sm), antiphospholipid antibodies, and complement levels (C3 and C4) 1.
- Assessment of disease activity by a validated index at each visit, organ damage annually, and general quality of life by patient history and/or by a 0–10 VAS (patient global score) at each visit, as well as evaluation of comorbidities and drug toxicity 1.
Laboratory Testing
- ANA is highly sensitive but not specific for SLE; a positive ANA (typically ≥1:80 titer) should prompt further testing with more specific antibodies like anti-dsDNA and anti-Sm.
- The use of anti-dsDNA autoantibodies in the diagnosis and follow-up of SLE is recommended, with consideration of their limitations and potential for inconsistency 1.
Classification Criteria
- The 2019 EULAR/ACR classification criteria can guide diagnosis, requiring a positive ANA plus additional clinical and immunological criteria totaling 10 or more points.
Clinical Considerations
- Early rheumatology consultation is recommended for suspected cases to ensure proper diagnosis and management of this complex autoimmune condition.
- A standardized core set of variables for the assessment and monitoring of patients with SLE in clinical practice should be used, including disease activity, organ damage, and quality of life 1.
From the Research
Evaluation Approach
To evaluate a patient for systemic lupus erythematosus (SLE), the following steps can be taken:
- Obtain a thorough medical history and perform a physical examination to identify any symptoms or signs suggestive of SLE, such as unexplained multisystem inflammatory disease, symmetric joint pain with inflammatory features, photosensitive rash, and cytopenias 2
- Order laboratory tests, including an antinuclear antibody (ANA) titer, which is the primary laboratory test used to diagnose SLE 3
- If the ANA titer is 1:40 or higher and the patient has characteristic multiorgan system involvement, a diagnosis of SLE can be made without additional testing 3
- However, if the ANA titer is 1:40 or higher but the patient does not meet full clinical criteria, additional testing, including tests for antibody to double-stranded DNA antigen and antibody to Sm nuclear antigen, should be performed 3
Laboratory Testing
Laboratory tests that can be helpful in the diagnosis of SLE include:
- ANA titer: a positive result is sensitive but not specific for SLE 3, 2
- Complete blood count: to evaluate for cytopenias, such as anemia, lymphopenia, and leukopenia 4
- Urinalysis: to evaluate for proteinuria or cellular casts 4
- Erythrocyte sedimentation rate: to evaluate for inflammation 4
- Anti-double-stranded DNA and anti-Sm antibody tests: to confirm the diagnosis of SLE in patients with a positive ANA titer but incomplete clinical criteria 3
Clinical Considerations
When evaluating a patient for SLE, it is essential to consider the following:
- SLE can present with a wide range of symptoms, including musculoskeletal, cutaneous, constitutional, neurologic, and renal manifestations 4
- Some patients may present with atypical manifestations, such as parotitis, quadriplegia, or severe abdominal pain 4
- A high index of suspicion is necessary to make the correct diagnosis of SLE, especially in patients with nonspecific symptoms, such as malaise and fatigue 2