HISTOLOGY AND HISTOPATHOLOGY

Cellular and Molecular Biology

 

Involvement of tenascin-C and PG-M/versican in flexor tenosynovial pathology of idiopathic carpal tunnel syndrome

M. Tsujii1, H. Hirata1, T. Yoshida2, K. Imanaka-Yoshida2, A. Morita3 and A. Uchida1

1Department of Orthopaedic Surgery, Faculty of Medicine, Mie University, Tsu, Mie, Japan, 2Department of Pathology, Faculty of Medicine, Mie University, Tsu, Mie, Japan and 3Department of Orthopaedic Surgery, Suzuka Kaisei General Hospital, Suzuka, Mie, Japan

Offprint requests to: Dr. Hitoshi Hirata, Department of Orthopaedic Surgery, Faculty of Medicine, Mie university, 2-174, Edobashi, Tsu, Mie prefecture, Japan. e-mail: h-hirata@clin.medic.mie-u.ac.jp


Summary. Increased intra-carpal-tunnel pressure due to swelling of the flexor tenosynovium is the most probable pathological mechanism of idiopathic carpal tunnel syndrome (CTS). To clarify the role of tenascin-C and PG-M/versican, which have often been found to be involved in tissue remodeling and vascular stenosis in the pathogenesis of CTS, we histologically and biochemically examined the production of extracellular matrix in the flexor tenosynovium from 40 idiopathic CTS patients. Tenascin-C was temporarily expressed in the vessel wall, synovial lining and fibrous tissue, with expression regulated differently in each tissue. Tenascin-C expression by vessels correlated with disease duration and appeared to be involved in vascular lesion pathology. Morphometric analysis showed that tenascin-C expression by small arteries is correlated with PG-M/versican expression in surrounding connective tissue. PG-M/versican was also present at the neointima of severely narrowed vessels.
Although tenascin-C expression by synovial lining and connective tissue shows marked regional variation and seems inconsistent, in vitro examination suggested that tenascin-C production by these tissues is regulated in response to mechanical strain on the flexor tenosynovium. Histol Histopathol 21, 511-518 (2006)

Key words: PG-M/versican, Tenascin-C, Idiopathic carpal tunnel syndrome, Tenosynovial thickening, Vascular lesion

DOI: 10.14670/HH-21.511