From the Guidelines
Lupus diagnosis should be based on the Systemic Lupus Erythematosus (SLE) classification criteria, which requires a positive antinuclear antibody (ANA) test as an entry criterion, followed by accumulation of points across clinical and immunological domains, as outlined in the most recent guidelines 1. The diagnosis of lupus is complex and multifaceted, involving a combination of clinical and immunological criteria. Clinical criteria include:
- Constitutional symptoms (fever)
- Hematologic abnormalities (leukopenia, thrombocytopenia, autoimmune hemolysis)
- Neuropsychiatric manifestations
- Mucocutaneous findings (oral ulcers, discoid rash, malar rash, photosensitivity)
- Serositis (pleural or pericardial effusion)
- Joint involvement (arthritis)
- Renal disorder (proteinuria, lupus nephritis) Immunological criteria include:
- Elevated anti-dsDNA antibodies
- Anti-Smith antibodies
- Antiphospholipid antibodies
- Low complement levels (C3, C4)
- Direct Coombs test It is essential to note that no single test confirms lupus, and diagnosis requires a comprehensive evaluation by a rheumatologist considering the pattern of symptoms, physical examination findings, and laboratory results 1. The use of anti-dsDNA autoantibodies in the diagnosis and follow-up of SLE is crucial, but it is essential to understand that these autoantibodies are not a homogeneous entity and can be observed in healthy individuals and other autoimmune syndromes 1. Early diagnosis and prompt treatment with antimalarials, corticosteroids, immunosuppressants, or biologics can prevent organ damage and improve quality of life, which is the primary goal of treatment, as outlined in the 2019 update of the EULAR recommendations for the management of SLE 1. Lupus is a chronic autoimmune disease with periods of flares and remissions, requiring ongoing monitoring and treatment adjustments to optimize health-related quality of life and prevent organ damage 1.
From the Research
Diagnostic Criteria for Lupus
The diagnostic criteria for lupus have undergone several changes over the years. Some key points to consider include:
- The American College of Rheumatology (ACR) first proposed criteria for SLE in 1971, which have since been revised in 1982 and 1997 2.
- The Systemic Lupus Collaborating Clinics proposed the SLICC criteria for SLE in 2012, which take into account new knowledge of autoantibodies and the importance of low complement 2.
- The European League Against Rheumatism (EULAR) and ACR proposed new classification criteria for SLE in 2019, which use antinuclear antibodies (ANA) as an entry criterion and include fever as a new criterion 3.
- The new EULAR/ACR 2019 classification criteria have a sensitivity of 96.1% and a specificity of 93.4% 3.
Key Diagnostic Factors
Some key factors to consider when diagnosing lupus include:
- Clinical manifestations such as skin lesions, arthritis, renal disorder, neurologic disorder, and hematologic changes 2.
- Serum anti-nuclear antibody, anti-ds-DNA antibody, and anti-Sm antibody are important biomarkers of SLE patients 2.
- A positive antinuclear antibody titer of 1:80 or greater is an obligatory entry criterion for the newest clinical criteria proposed by the EULAR/ACR in 2019 4.
Diagnosis and Treatment
Diagnosis and treatment of lupus involve:
- A comprehensive approach that takes into account the patient's medical history, physical examination, and laboratory results 5, 4.
- Management of SLE is directed at complete remission or low disease activity, minimizing the use of glucocorticoids, preventing flare-ups, and improving quality of life 4.
- Hydroxychloroquine is recommended for all patients with SLE to prevent flare-ups, organ damage, and thrombosis and increase long-term survival 4.