Lysyl oxidase activity in the cells of flexor retinaculum of individuals with carpal tunnel syndrome.

Lysyl oxidase (LO) is produced by myofibroblast cells in some tissues and can be influenced by transforming growth factor beta 1 (TGF beta 1). Myofibroblast-like cells are present in the flexor reticulum of patients with carpal tunnel syndrome (CTS). The goal of the current study was to determine LO activity and the effects of TGF beta 1 on LO expression in the cells from patients with CTS. Tissues from both hands of five individuals with CTS were used for this study. LO activity with and without TGF beta 1 stimulation was assayed in 7-day cell culture specimens. A significant difference in LO activity among individual patients, but not between right and left hands of the same patient, was observed. There was no correlation between the severity of CTS determined by nerve conduction studies and LO activity. Addition of TGF beta 1 significantly increased LO in all cell lines.