Anti-Jo-1 antibody-positive patients show a characteristic necrotizing perifascicular myositis.

Idiopathic inflammatory myopathies can be classified as polymyositis, dermatomyositis, immune-mediated necrotizing myopathy, sporadic inclusion body myositis or non-specific myositis. Anti-Jo-1 antibody-positive patients are assigned to either polymyositis or dermatomyositis suggesting overlapping pathological features. We aimed to determine if anti-Jo-1 antibody-positive myopathy has a specific morphological phenotype. In a series of 53 muscle biopsies of anti-Jo-1 antibody-positive patients, relevant descriptive criteria defining a characteristic morphological pattern were identified. They were tested in a second series of anti-Jo-1 antibody-positive patients and compared to 63 biopsies from patients suffering from other idiopathic inflammatory myopathies. In anti-Jo-1 antibody-positive patients, necrotic fibres, which strongly clustered in perifascicular regions, were frequently observed. Sarcolemmal complement deposition was detected specifically in perifascicular areas. Inflammation was mainly located in the perimysium and around vessels in 90.6%. Perimysial fragmentation was observed in 90% of cases. Major histocompatibility complex class I staining was diffusely positive, with a perifascicular reinforcement. Multivariate analysis showed that criteria defining perifascicular pathology: perifascicular necrosis, atrophy, and perimysial fragmentation allow the distinction of anti-Jo-1 antibody-positive patients, among patients suffering from other idiopathic inflammatory myopathies. Anti-Jo-1 antibody-positive patients displayed perifascicular necrosis, whereas dermatomyositis patients exhibited perifascicular atrophy.

Mescam-Mancini L ，Allenbach Y ，Hervier B ，Devilliers H ，Mariampillay K ，Dubourg O ，Maisonobe T ，Gherardi R ，Mezin P ，Preusse C ，Stenzel W ，Benveniste O ... -  《-》

Development of a New Classification System for Idiopathic Inflammatory Myopathies Based on Clinical Manifestations and Myositis-Specific Autoantibodies.

Mariampillai K ，Granger B ，Amelin D ，Guiguet M ，Hachulla E ，Maurier F ，Meyer A ，Tohmé A ，Charuel JL ，Musset L ，Allenbach Y ，Benveniste O ... -  《-》

Myopathy with anti-Jo-1 antibodies: pathology in perimysium and neighbouring muscle fibres.

Mozaffar T ，Pestronk A 《-》

Redefining dermatomyositis: a description of new diagnostic criteria that differentiate pure dermatomyositis from overlap myositis with dermatomyositis features.

Troyanov Y ，Targoff IN ，Payette MP ，Raynauld JP ，Chartier S ，Goulet JR ，Bourré-Tessier J ，Rich E ，Grodzicky T ，Fritzler MJ ，Joyal F ，Koenig M ，Senécal JL ... -  《-》

RIG-I expression in perifascicular myofibers is a reliable biomarker of dermatomyositis.

Suárez-Calvet X ，Gallardo E ，Pinal-Fernandez I ，De Luna N ，Lleixà C ，Díaz-Manera J ，Rojas-García R ，Castellví I ，Martínez MA ，Grau JM ，Selva-O'Callaghan A ，Illa I ... -  《-》