SCL-70 Antibody Test

The SCL-70 Antibody Test detects anti-topoisomerase I antibodies (SCL-70) in the blood. These antibodies are associated with systemic sclerosis (scleroderma), particularly the diffuse form, which affects the skin and internal organs.

Why is the Test Done?

A doctor may order an SCL-70 antibody test if a patient has symptoms of systemic sclerosis, including:

✅ Skin thickening and tightening (especially on hands, face, and arms)
✅ Raynaud’s phenomenon (fingers turning white or blue in response to cold)
✅ Joint pain or swelling
✅ Difficulty swallowing (esophageal dysmotility)
✅ Shortness of breath (lung involvement like pulmonary fibrosis)
✅ Fatigue and general weakness

This test helps in diagnosing systemic sclerosis (scleroderma) and differentiating between limited and diffuse forms of the disease.

How is the Test Done?

1. Blood Sample Collection:

   • A blood sample is drawn from a vein.
   • The sample is tested using ELISA (Enzyme-Linked Immunosorbent Assay) or Immunoblotting.

2. Detection of SCL-70 Antibodies:

   • Positive result suggests a higher likelihood of diffuse systemic sclerosis.

Interpreting the Results

📌 Note:

• A positive SCL-70 test does not confirm scleroderma alone—it must be correlated with clinical symptoms and other tests.
• Some people with systemic sclerosis may test negative for SCL-70 antibodies.
• ANA (Antinuclear Antibody) test is often positive in scleroderma patients.

Next Steps After a Positive Result

🔬 Additional Tests May Be Ordered:

• ANA Test (Antinuclear Antibody) – Usually positive in autoimmune diseases.
• Centromere Antibodies – More common in limited scleroderma (CREST syndrome).
• Pulmonary Function Tests (PFTs) – To assess lung involvement.
• Echocardiogram – To check for pulmonary hypertension.
• Skin Biopsy – If needed, to confirm systemic sclerosis.

💊 Management & Treatment:

• No cure, but treatment focuses on symptom control:
  • Immunosuppressants (Methotrexate, Mycophenolate, Cyclophosphamide) for severe cases.
  • Vasodilators (Nifedipine, Sildenafil) for Raynaud’s phenomenon.
  • Proton pump inhibitors (PPIs) for esophageal reflux.
  • Physical therapy to maintain mobility and flexibility.