Scl-70 antibody is seen in 20% of people with scleroderma (also known as systemic sclerosis), and in some people with CREST syndrome (calcinosis, Raynaud, esophageal dysfunction, sclerodactyly, telangiectasia).
These syndromes are also associated with a high frequency of speckled pattern immunofluorescent antinuclear antibody tests. Scl-70 may identify a subset of scleroderma patients with severe skin, joint, and lung disease. In addition, the presence of Scl-70 in Raynaud phenomenon may indicate a poor prognosis.
Negative results do not necessarily rule out the presence of SSc. If clinical suspicion remains, consider further testing for centromere, RNA polymerase III and U3-RNP, PM/Scl, or Th/To antibodies.
Progressive Systemic Sclerosis (PSS), is a chronic systemic rheumatic disease that can effect many organ systems including the skin, the GI tract, the heart, lungs and kidneys. It occurs more commonly in females and its onset most frequently in the ages from 20 to 50 years. Sera (=plural of serum) from people with PSS contain several autoantibodies to different nuclear antigens including Scl-70, Sm and centromere antigens. Antibody to Scl-70 (topoisomerase I) is present in around 20% of patients with scleroderma, particularly those patients with a more progressive form of the disease. Scl-70 is difficult to detect by immunofluorescent studies where it gives fine speckles within the nucleus. Scl-70 antigen is present in the ENAscreen. Samples positive for the ENAscreen but negative for Ro, La, RNP, Sm or the centromere antigen will automatically be tested for Scl-70. However, since many Scl-70 sera are also positive for other ENAs (Ro52or RNP) it is best to specifically request Scl70 or give scleroderma as clinical details where appropriate.
The presence of Scl-70 antibodies (also referred to as topoisomerase I, topo-I or ATA) is considered diagnostic for systemic sclerosis (SSc). Scl-70 antibodies alone are detected in about 20 percent of SSc patients and are associated with the diffuse form of the disease, which may include specific organ involvement and poor prognosis.
Scl-70 antibodies have also been reported in a varying percentage of patients with systemic lupus erythematosus (SLE).
The levels do not correlate with disease activity.
$79 per year
$6.60 per month billed annually
$79 per year
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place.Learn More