Sporadic inclusion body myositis: morphology, regeneration, and cytoskeletal structure of muscle fibres

Autor: T. Ansved, S Arnardottir, K Borg
Rok vydání: 2004
Předmět:
Zdroj: Journal of Neurology, Neurosurgery & Psychiatry. 75:917-920
ISSN: 0022-3050
DOI: 10.1136/jnnp.2003.018994
Popis: Objective: To characterise morphological abnormalities in relation to muscle fibre type in sporadic inclusion body myositis (s-IBM). Methods: 14 muscle biopsies from 11 patients with s-IBM were characterised for morphological abnormalities and fibre type composition as well as muscle fibre regeneration and cytoskeletal structure, using histochemical and immunohistochemical techniques. Results: Morphological abnormalities included inflammatory infiltrates and ‘‘rimmed vacuoles,’’ and pronounced variation in fibre size. There were no significant differences in fibre type composition between s-IBM patients and controls based on the myofibrillar ATPase staining. A differential effect on muscle fibre sizes was noted, type II fibres being smaller in the s-IBM patients than in the controls. Conversely, the mean type I muscle fibre diameter in the s-IBM patients was larger than in the controls, though this difference was not significant. An ongoing intense regeneration process was present in s-IBM muscle, as indicated by the expression of neonatal myosin heavy chain, vimentin, and CD56 (Leu-19) in most of the muscle fibres. The cytoskeletal proteins dystrophin and desmin were normally expressed in s-IBM muscle fibres that were not undergoing degeneration or regeneration. Conclusions: There are extensive morphological and morphometric alterations in s-IBM, affecting different muscle fibre types in different ways. The cytoskeletal structure of type I and II muscle fibres remains unaffected in different stages of the disease.
Databáze: OpenAIRE