Scl-70 Antibody - Scleroderma – BC279
🔬 Autoimmune Disease MarkerReport: Next day Evening (Except Sunday)
Sample Type: Blood (Serum)
Test Code: BC279
The Scl-70 Antibody test is a blood test that detects autoantibodies against topoisomerase I, an enzyme found in the cell nucleus. These antibodies are highly specific markers for Systemic Sclerosis (Scleroderma), particularly the diffuse cutaneous form of the disease.
✔ A key diagnostic marker for Systemic Sclerosis (Scleroderma).
✔ Helps differentiate Scleroderma from other connective tissue diseases.
✔ Associated with the diffuse cutaneous subtype and increased risk of internal organ involvement.
✔ Part of the ENA (Extractable Nuclear Antigen) panel, often ordered after a positive ANA test.
Scl-70: A Specific Clue for Scleroderma
Systemic Sclerosis, commonly known as Scleroderma, is a chronic autoimmune disease characterized by the hardening and tightening of the skin and connective tissues. It can also affect internal organs like the lungs, heart, kidneys, and digestive tract. Diagnosing Scleroderma involves evaluating clinical symptoms, skin changes, and specific autoantibodies.
The Scl-70 antibody (anti-topoisomerase I) is one such crucial autoantibody. Its presence is found in a significant subset of Scleroderma patients and is highly specific for the disease. While not all Scleroderma patients will have Scl-70 antibodies, finding them strongly supports the diagnosis.
Association with Diffuse Cutaneous Systemic Sclerosis (dcSSc)
Scleroderma is broadly classified into limited and diffuse cutaneous forms. The Scl-70 antibody is particularly associated with the **diffuse cutaneous subtype (dcSSc)**. This form is characterized by more widespread and rapid skin thickening and carries a higher risk of early and significant internal organ involvement, especially interstitial lung disease (ILD).
Therefore, a positive Scl-70 result not only aids in diagnosis but also provides important prognostic information, alerting the doctor to monitor closely for potential lung or other organ complications.
Frequently Asked Questions (FAQ)
Scleroderma (Systemic Sclerosis) is an autoimmune disease where the immune system attacks connective tissues, leading to excessive collagen production. This causes hardening and tightening of the skin and can also damage internal organs.
Your doctor likely suspects Scleroderma based on your symptoms (like skin thickening, Raynaud's phenomenon, or internal organ issues). The Scl-70 test is a specific marker that helps confirm the diagnosis, especially for the diffuse form of the disease.
A positive Scl-70 test is highly specific for Scleroderma. While rare false positives can occur, in the presence of compatible clinical symptoms, a positive result strongly supports the diagnosis.
Yes. Not all patients with Scleroderma have Scl-70 antibodies. Other autoantibodies (like anti-centromere or anti-RNA polymerase III) are associated with different subtypes of the disease. Diagnosis also relies heavily on clinical findings.
No, fasting is not required for the Scl-70 antibody blood test.