Myositis‐specific antibodies (MSA) help organize children with Juvenile Dermatomyositis (JDM) into distinct phenotypes. This study primarily aimed to investigate the association between lipodystrophy and anti‐P155/140 as determined by DXA assessment of fat distribution. The secondary aim is to evaluate the correlation between nailfold capillary system damage and anti‐P155/140.

For this study, children suffering from JDM for at least five years were involved. The study population was divided into three groups (MSA negative, anti‐P155/140, other MSA). Lipodystrophy was assessed by DXA fat distribution and physician assessment. The documentation of nailfold capillary end‐row loops (ERL) was obtained at diagnosis. In total, 96 subjects (33% MSA negative, 44% anti‐P155/140, 23% other MSA) were included. There was no significant difference in lipodystrophy, age, or disease activity scores between the three groups. However, the anti‐P155/140 group had significantly decreased (ERL) count at baseline as well as a prolonged duration of untreated disease at diagnosis. Although, the anti‐P155/140 group had lesser patients than the other two groups, with respect to monophasic disease courses.

In conclusion, generalized lipodystrophy frequency was equivalent in all three groups based on physician assessments and Trunk: Leg fat ratios. The anti‐P155/140 group had a more significant loss of ERL, suggesting that this MSA may impact the vascular component of JDM.