XXXX -related clinical and pathological features are associated with severe juvenile dermatomyositis.

@entity1 @entity82 @entity455 @entity5442 @entity39 @entity4 @entity344 @entity425 @entity393
OBJECTIVE: Outcome of JDM is highly heterogeneous. Our objective was to determine clinical and muscle biopsy features associated with poor outcome and response to treatment. METHODS: Clinical data and muscle biopsy were obtained from a monocentric cohort of 29 @entity1 . Clinical subgroups were defined by latent class model analysis of initial and follow-up parameters. Myopathological features were analysed using validated scores. @entity393 was determined on reconstructions of transversal sections and assessed in the different age groups to take into account variations of muscle capillarization during post-natal development. Regression models were used to identify initial predictors of therapeutic response. RESULTS: Two distinct homogeneous subgroups of @entity1 were identified according to clinical severity and pathological findings. The smallest group of @entity1 (7/29) presented with severe JDM. Compared with the other group (22/29), @entity1 had more severe @entity425 at disease onset, low remission rate at 12 months, frequent @entity4 or @entity344 and higher myopathological scores (capillary dropout, perifascicular @entity39 /regeneration, fibres with internal myonuclei and @entity82 subscores). Relevance of capillary dropout to JDM severity was substantiated by age-based analysis, confirming its major role in JDM pathophysiology. Most of these manifestations could be related to @entity455 (limb @entity4 , @entity344 , capillary dropout). Furthermore, Childhood @entity5442 Assessment Scale <34 with either @entity344 or muscle endomysial @entity82 at disease onset were the best predictors of poor response to treatment. CONCLUSION: @entity455 is prominent in severe JDM. Simple criteria can be used at initial evaluation to identify @entity1 requiring a more intensive therapy.
