Antibodies to Scl-70, also known as anti-topoisomerase I antibodies, produce three ANA patterns: homogeneous, speckled, and nucleolar. This is because the Scl-70 antigen is present in all three areas.
In cases of mixed homogeneous and speckled ANAs, follow-up testing for anti-dsDNA and anti-ENA antibodies is necessary. When mixed patterns are titered, the endpoint for each pattern is reported.
This pattern is reported as "ANA positive, Homogeneous, Nucleolar and Speckled; titering is necessary."
It should be noted that anti-Scl-70 cannot be identified simply by the ANA patterns. Follow-up ENA testing is necessary.
