Quid de la détection des anticorps anti-TIF1γ dans les dermatomyosites ?

Abstract

AbstractThe classification of idiopathic inflammatory myopathies (IBD) is evolving, with the consideration, in addition to clinicopathological criteria, of the presence of autoantibodies specific to myositis for the diagnosis and identification of clinical forms.The diagnosis of dermatomyositis (DM) is based on clinical, histological, imaging criteria and the demonstration of myositis-specific autoantibodies (MSA). Within these antibodies, anti-TIF1γ have a special place due to their high prevalence in juvenile DM and in cancer-associated DM. Anti-TIF1γ antibodies are present in 7-31% of adult DMs. DMs with anti-TIF1γ are associated with cancer in more than half of cases in adults (38-75%), whereas this is not the case in juvenile DMs. The role of the TIF1γ protein in the tumor process and of autoantibodies in the triggering of DM are the subject of numerous hypotheses, but without any definitive conclusion currently.Given the diagnostic and prognostic importance of the presence of anti-TIF1γ antibodies, it is essential to have reliable tests suitable for routine practice to characterize them. The reference technique, immunoprecipitation, is not suitable for the routine laboratory. Immunodots are practical but their performance is not optimal in terms of sensitivity and specificity. Elisa and the particle-based multi-analyte technology (PMAT)-type automated technique seem to present performances close to immunoprecipitation but with a practicability adapted to routine use.