TRIM21 and myositis disease: An anti-SSA was ordered in 101 patients. A positive anti-SSA was noted in 10 patients (10.0%). Of those, nine patients (9.0%) had a more specific antibody identified on the extended myositis antibody panel. In one patient (1.0%), a positive anti-SSA did not lead to the detection of a positive MAA. There were 33 patients with a negative anti-SSA who ultimately had a positive antibody on the extended myositis antibody panel (32.0%). The anti-SSA results indicated a sensitivity of 21.4%, a specificity of 98.3%, a PPV of 90.0%, and NPV of 63.7%.