From the Guidelines
The recommended laboratory workup for suspected scleroderma should include antinuclear antibody (ANA) testing, scleroderma-specific autoantibodies (anti-centromere, anti-Scl-70/topoisomerase I, and anti-RNA polymerase III), complete blood count (CBC), comprehensive metabolic panel, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). When considering scleroderma in the differential diagnosis, it is essential to conduct a thorough laboratory workup to facilitate early diagnosis and determine disease subtype and organ involvement. The following tests are recommended:
- Antinuclear antibody (ANA) testing: ANA is positive in over 95% of scleroderma patients 1
- Scleroderma-specific autoantibodies:
- Anti-centromere antibodies are associated with limited cutaneous scleroderma and increased risk of pulmonary hypertension
- Anti-Scl-70 antibodies suggest diffuse cutaneous disease with higher risk of interstitial lung disease
- Anti-RNA polymerase III antibodies are associated with diffuse cutaneous scleroderma and increased risk of scleroderma renal crisis 1
- Complete blood count (CBC): may reveal anemia of chronic disease or microangiopathic hemolytic anemia in cases with renal crisis
- Comprehensive metabolic panel: can identify renal involvement
- Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): elevated inflammatory markers indicate active disease Additional testing should include:
- Urinalysis: helps detect early renal involvement
- Creatine kinase: elevation may suggest muscle involvement
- Pulmonary function tests with diffusion capacity: essential for assessing lung involvement This comprehensive workup is crucial for appropriate management and should be guided by the most recent and highest quality evidence, such as the 2023 update on state-of-the-art evidence in the treatment of systemic sclerosis 1.
From the Research
Lab Workup for Scleroderma
When considering scleroderma in the differential diagnosis, the following lab workup is recommended:
- Antinuclear antibodies (ANA) testing: The presence of ANA is a key factor in the diagnosis of scleroderma 2, 3, 4, 5
- Anti-centromere antibodies: These antibodies are commonly found in patients with limited systemic scleroderma, also known as CREST syndrome 4, 5
- Anti-Scl-70 antibodies: These antibodies are specific for systemic sclerosis and are often associated with diffuse cutaneous involvement 3, 5
- Capillaroscopic analysis: Nailfold videocapillaroscopic (NVC) analysis can help distinguish between primary and secondary Raynaud's phenomenon and allow for early detection of scleroderma 6
- Other tests: Depending on the clinical presentation and suspected organ involvement, other tests such as pulmonary function tests, echocardiogram, and renal function tests may be necessary 3
Key Findings
- The presence of ANA, anti-centromere, and anti-Scl-70 antibodies can help support the diagnosis of scleroderma 2, 3, 4, 5
- The distribution of sclerosis and the presence of Raynaud's phenomenon are also important factors in the diagnosis of scleroderma 2, 3, 6
- Early detection and diagnosis of scleroderma are crucial for initiating appropriate treatment and improving patient outcomes 2, 3, 6