TRIM21 and dermatomyositis: All anti-Ro52 Ab-positive patients reacted against the full Ro52 antigen by a line immunoassay without difference in AU/ml among the various diseases (mean ± SD: 76.55 ± 23.13 AU/ml in SSc compared to 79.8 ± 24.3 AU/ml in SjS; 80.39 ± 28.26 AU/ml in SLE; 81.73 ± 16.93 AU/ml in DM and 83.6 ± 35.2 AU/ml in PBC, p > 0.05 for all) (Figure 2).