AntiScl70

Anti-Scl-70, also known as anti-topoisomerase I, is an autoantibody directed against the nuclear enzyme DNA topoisomerase I. It is one of the disease-specific autoantibodies identified in systemic sclerosis (scleroderma) and is most commonly associated with the diffuse cutaneous form of the disease.

Clinical significance of anti-Scl-70 is its association with diffuse cutaneous systemic sclerosis and an increased risk of interstitial lung disease. The presence of this antibody often correlates with more extensive skin involvement and a higher likelihood of pulmonary fibrosis in some patients. However, individual disease course varies, and antibody status is one factor among many used to assess prognosis and guide monitoring.

Detection and testing: anti-Scl-70 can be detected in serum by several laboratory methods, including enzyme-linked immunosorbent assay (ELISA), immunoblot, and immunoprecipitation. It may be included in autoantibody panels for systemic sclerosis. Indirect immunofluorescence on HEp-2 cells can show a nonspecific nucleolar or speckled ANA pattern, but confirmation with a specific test is typically required.

Prevalence and population notes: anti-Scl-70 is found in a subset of systemic sclerosis patients, with frequency varying across cohorts and populations. It tends to be more common in diffuse cutaneous disease and is observed with higher frequency in some populations of European descent.

Related information: in systemic sclerosis, autoantibody profiles—alongside anticentromere antibodies and anti-RNA polymerase III—help define clinical subsets and inform management strategies.