@article{3003450,
    title = "Polymyositis with mitochondrial pathology or atypical form of sporadic inclusion body myositis: case series and review of the literature",
    author = "Papadimas, G.K. and Kokkinis, C. and Xirou, S. and Chrysanthou, M. and Kararizou, E. and Papadopoulos, C.",
    journal = "Rheumatology International",
    year = "2019",
    volume = "39",
    number = "8",
    pages = "1459-1466",
    publisher = "Springer-Verlag",
    issn = "0172-8172, 1437-160X",
    doi = "10.1007/s00296-019-04314-8",
    keywords = "calcium;  calcium plus colecalciferol;  immunoglobulin;  methotrexate;  methylprednisolone;  mitochondrial DNA;  prednisone;  glucocorticoid;  immunosuppressive agent;  mitochondrial DNA, adult;  aged;  case report;  clinical article;  disorders of mitochondrial functions;  drug dose reduction;  female;  histopathology;  human;  human tissue;  inclusion body myositis;  leg muscle;  middle aged;  muscle biopsy;  muscle weakness;  polymyositis;  priority journal;  Review;  sporadic inclusion body myositis;  biopsy;  differential diagnosis;  drug effect;  gene deletion;  genetics;  inclusion body myositis;  muscle mitochondrion;  pathology;  pathophysiology;  polymyositis;  predictive value;  skeletal muscle;  treatment outcome, Adult;  Aged;  Biopsy;  Diagnosis, Differential;  DNA, Mitochondrial;  Female;  Gene Deletion;  Glucocorticoids;  Humans;  Immunosuppressive Agents;  Middle Aged;  Mitochondria, Muscle;  Muscle Weakness;  Muscle, Skeletal;  Myositis, Inclusion Body;  Polymyositis;  Predictive Value of Tests;  Treatment Outcome",
    abstract = "Polymyositis with mitochondrial pathology (PM-Mito) is a rare form of idiopathic inflammatory myopathy with no definite diagnostic criteria and similarities to both PM and sporadic inclusion body myositis (s-IBM). The aim of this study is to address the dilemma of whether PM-Mito is a subtype of inflammatory myopathy or represents a disease falling into the spectrum of s-IBM. Herein, we report four female patients diagnosed with PM-Mito, highlighting their rather atypical clinical and histopathological characteristics that seem to indicate a diagnosis away from s-IBM. Muscle weakness was rather proximal and symmetrical and lacked the selective pattern observed in s-IBM. Patients had large-scale deletions in mtDNA, reflecting the mitochondrial component in the pathology of the disease. Conclusively, our study adds to the limited data in the literature on whether PM-Mito is a distinct form of myositis or represents a prodromal stage of s-IBM. Although the latter seems to be supported by a substantial body of evidence, there are, however, important differences, such as the different patterns of muscle weakness, and the good response to treatment observed in some patients. Larger-scale studies are certainly needed to clarify pathogenesis and clinical characteristics of PM-Mito patients, especially in therapeutic and prognostic terms. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature."
}