Interleukin-6 secretion by fibroblasts in carpal tunnel syndrome patients is associated with trigger finger and inhibited by tranilast.

Introduction: In this study we aimed to clarify the association between interleukin-6 (IL-6) secretion in fibroblasts in carpal tunnel syndrome (CTS) patients and their biophysical parameters, including association with trigger finger and whether tranilast inhibits IL-6 secretion in fibroblasts.

Methods: Fibroblasts were obtained from tenosynovial tissue harvested from idiopathic CTS patients undergoing carpal tunnel release and tenosynovectomy and cultured in media containing tranilast with or without tumor necrosis-α (TNF-α) or interleukin-1β (IL-1β). Their proliferation was evaluated and secreted IL-6 levels and IL-6 mRNA expression were quantified. Correlations between IL-6 concentration and patient characteristics were examined.

Results: IL-6 secretion was significantly associated with trigger finger (P = .001). Tranilast inhibited fibroblast proliferation in a dose-dependent manner and suppressed IL-6 secretion.

Discussion: IL-6 overproduction in tenosynovial tissue may account for the association between CTS and trigger finger. Future studies should investigate whether tranilast can be used to treat patients with CTS.