Test Code #
CPT Code(s) #
SCl-70 (for Scleroderma)
LE, other Connective Tissue Diseases
Type of Study:
Negative <20 Units
Weak Positive 20-39 Units
Moderate Positive 40-80 Units
Strong Positive >80 Units
Assay performed once per week. Report availability is within one week from the time of specimen receipt.
Collect 5-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into red capped tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8ºC) up to five days and frozen (-20ºC or lower) up to one year.
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). 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.