Volume 8 Supplement 1

15th International Conference on Human Retroviruses: HTLV and Related Viruses

Open Access

Histopathologic differences between human T-lymphotropic virus type 1 (HTLV-1)-positive and HTLV-1-negative polymyositis

  • Hazem M Abdullah1,
  • Itsuro Higuchi2,
  • Ryuji Kubota3,
  • Eiji Matsuura2,
  • Akihiro Hashiguchi2,
  • Nashwa H Abdelbary1, 2,
  • Yukie Inamori2,
  • Hiroshi Takashima2 and
  • Shuji Izumo1Email author
Retrovirology20118(Suppl 1):A39


Published: 6 June 2011


Epidemiological studies show that human T-lymphotropic virus type 1 (HTLV-1) is closely associated with polymyositis (PM). However, the pathogenic roles of HTLV-1 in PM remain unknown. This study aims to assess skeletal muscle morphology in the presence of HTLV-1 infection to compare the histopathological findings of HTLV-1-positive and HTLV-1-negative PM.


Among the 68 patients with inflammatory myopathy diagnosed through muscle biopsy over the previous 10 years at Kagoshima University Hospital, we retrospectively selected 21 patients with PM not associated with any other disease; we evaluated HTLV-1 positivity through serology, confirmed it by nested PCR using DNA extracted from muscles, and then assessed the tissue viral load. Meticulous histopathological examination was performed using routine histochemical and immunohistochemical staining, and specimens from selected cases were examined by electron microscopy.


The clinical and histopathological findings of muscle biopsy specimens of HTLV-1-positive (n = 11) and HTLV-1-negative PM cases (n = 10) were compared. Compared with HTLV-1-negative patients, HTLV-1-positive patients exhibited protracted clinical courses, prominent endomysial infiltrates, infrequent necrotic fibers, and prominent regenerative activities. Moreover, they showed frequent cytochrome c oxidase deficiency and ultrastructural abnormalities in mitochondria.


These differences are significant but not specific to HTLV-1-positive PM. Therefore, HTLV-1 may induce the clinical and histopathological modifications of PM observed in this study.

Authors’ Affiliations

Division of Molecular Pathology, Center for Chronic Viral Diseases, Kagoshima University, Kagoshima
Department of Human Pathology, Faculty of Medicine, Mansoura University
Department of Neurology and Geriatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima


© Abdullah et al; licensee BioMed Central Ltd. 2011

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.