Use: Anti-TIF-1gamma (P155) antibodies are present in 15-38% of adult DM and 20-30% in JDM. Highly associated with malignancy, which is found in 50-75% of positive adult patients; 89% specificity and 78% sensitivity for diagnosing cancer-associated DM; no cancer association in children.

Limitations: This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Methodology: Enzyme-linked immunosorbent assay (ELISA)