Recently, a number of myositis-specific and -associated autoantibodies (MSAs/MAAs) have been identified and well characterized, and commercial assays for their detection have become available.<b>Areas covered</b>: There is accumulating evidence showing the utility of MSAs/MAAs in diagnosis of DM and in predicting clinical courses and outcomes in patients with DM as convenient biomarkers, i.e. an association of ILD with anti-ARS, anti-MDA5 and anti-SAE; and malignancy with anti-TIF1-γ, anti-NXP2, and anti-SAE in adults.
The significantly lower frequency of anti-ARS antibodies and significantly higher frequency of anti-MDA5 antibodies in the Chinese patients were observed in the classic DM subset (14.7 % [10/68] versus 46.4 % [26/56], respectively, P < 0.001, and 45.6 % [31/68] versus 5.4 % [3/56], respectively, P < 0.001) and CADM subset (8.0 % [2/25] versus 28.8 % [15/52], respectively, P = 0.04, and 88.0 % [22/25] versus 44.2 % [23/52], respectively, P = 0.0002), but not in the PM subset.