- Last Update On : 2013-03-05
Scl-70 is an antigen present on topoisomerase I, which is an ubiquitous intranuclear enzyme that mediates the twisting and untwisting of the DNA helix during gene transcription. It is a basic nuclear protein with a molecular weight of 70, 000 daltons. Antibodies directed against Scl-70 usually give a nucleolar ANA patterns and are present exclusively in 70% of patients with severe, diffuse form of progressive systemic sclerosis, also known as scleroderma. The presence of Scl-70 antibody is not predictive of either cardiac or renal involvement.
Results are reported as negative or positive. Reference value is negative.
Specimen requirement is one SST tube of blood.