What tests can detect lupus erythematosus?
Disease description:
Recently, someone suggested that I might have developed lupus erythematosus, which startled me. I would like to ask the doctor, what tests can be done to diagnose lupus erythematosus?
Doctor's answer (1)
Dr. Yang Tiesheng
To confirm a diagnosis of lupus erythematosus, a series of comprehensive examinations is usually required. The following are some of the tests that may be performed:
1. Clinical evaluation: Includes observation for mucocutaneous manifestations such as butterfly-shaped rash, ring-shaped rash, and symptoms of musculoskeletal involvement such as joint swelling and pain.
2. Laboratory tests: Complete blood count (CBC) to check for abnormalities in the number of white blood cells, red blood cells, and other indicators such as erythrocyte sedimentation rate (ESR) to assess systemic involvement. Urinalysis can help determine whether kidney damage exists, such as proteinuria or hematuria.
3. Antinuclear antibody (ANA) testing: ANA is the most common autoantibody in patients with lupus erythematosus. A positive result suggests the possible presence of an autoimmune disease but must be interpreted in combination with other indicators.
4. Specific antibody testing: Includes anti-double-stranded DNA (anti-dsDNA) antibodies and anti-Smith (anti-Sm) antibodies. These antibodies have high specificity for lupus erythematosus and aid in confirming the diagnosis.
5. Complement level testing: Decreased levels of complement components C3 and C4 are commonly seen in patients with active-phase lupus erythematosus, reflecting impaired clearance of immune complexes.
6. Imaging studies: Such as chest X-rays and echocardiography, used to evaluate involvement of organs like the lungs and heart.
7. Skin biopsy: In patients with prominent skin lesions, skin biopsy can provide histopathological evidence.
