{"id":"anti-scl-70","name":"Anti-Scl-70 (Topoisomerase I) Antibody","shortName":"Anti-Scl-70","aliases":["Scl-70 Antibody","Anti-Scl-70","Topoisomerase I Antibody","Scleroderma Antibody (Scl-70)","Anti-Topo I","Scl 70 Ab","Anti-Scl-70 Antibody","Scleroderma (Scl-70) (ENA) Antibody, IgG","Scleroderma (Scl-70) Antibody, IgG","Anti-Scleroderma (Scl-70) (ENA) Antibody","Scl70","Topo 1","Topoisomerase 1 Antibody","Anti-Topoisomerase I Antibody","Autoantibodies to Scl 70 Antigen"],"abbreviations":["Scl-70","anti-Scl-70","anti-topo I"],"loinc":[{"code":"47322-3","primary":true},{"code":"26975-3","primary":false},{"code":"27416-7","primary":false},{"code":"8092-9","primary":false}],"specimen":"serum","units":[{"ucum":"[arb'U]/mL","display":"AU/mL"}],"referenceRanges":[{"population":"Adults","low":0,"high":29,"unit":"[arb'U]/mL","unitDisplay":"AU/mL","note":"ARUP multiplex bead assay, reported in AU/mL (arbitrary units). ARUP reads 29 or less as negative, 30 to 40 as equivocal and 41 or more as positive, and prints its reference interval as 40 or less, which includes the equivocal zone. Units and cutoffs are specific to each kit and are not interchangeable: for example, University of Iowa Hospitals reports an antibody index with a reference range of 1.0 AI or less. Use the cutoff and flag printed on your own report.","sources":[{"title":"Scleroderma (Scl-70) (ENA) Antibody, IgG (test 0050599)","url":"https://ltd.aruplab.com/Tests/Pub/0050599","publisher":"ARUP Laboratories"},{"title":"SCL-70 Antibody","url":"https://www.healthcare.uiowa.edu/path_handbook/handbook/test1694.html","publisher":"UI Health Care (University of Iowa Hospitals & Clinics) Laboratory Services Handbook"}]}],"review":{"status":"ai-verified","label":"AI-verified against cited sources. Awaiting expert review","lastReviewed":"2026-10-03"},"summary":"Antibodies against an enzyme called topoisomerase I. A positive result is linked to systemic sclerosis (scleroderma), especially the diffuse form of the disease.","url":"https://bloodtesttracker.com/markers/anti-scl-70","notice":"Information, not medical advice. Ranges differ between labs, so the range on your own report is the one your result is judged against."}