Are myofibroblasts activated in idiopathic carpal tunnel syndrome? an immunohistochemical study

This study aims to investigate whether myofibroblasts participate in the fibrotic process of idiopathic carpal tunnel syndrome (CTS).

Forty patients (12 males, 28 females; median age 50.85 ± 11.2 years; range 30 to 71 years) who were operated in our clinic between March 2010 and August 2010 were included in the study. Twenty-five idiopathic CTS patients were assigned to the study group, and 15 trauma patients were assigned to the control group. Samples were taken from both transverse carpal ligament and subsynovial connective tissue (SSCT) of participants and they were analyzed by immunohistochemical method. Four immunohistochemical markers were used to analyze myofibroblast existence and vascular wall thickness (alpha smooth muscle actin [α-SMA]), collagen type IV antibodies, and T (CD3) and B (CD20) lymphocytes.

The existence of myofibroblasts (α-SMA) in SSCT of patients who were in early phase of idiopathic CTS was shown through the positive reaction of their antibodies with fibroblasts. A significantly increased reaction of α-SMA and collagen antibodies in vascular structure of SSCT demonstrated increased vascular wall thickness and vascularity in the study group (p<0.01). No significant difference was detected between the two groups in terms of T and B lymphocyte antibody reaction (inflammation).

The findings of this study indicate a potential for myofibroblasts to be activated during the early phase of the disease and contribute to the onset of disease. Further studies with larger sample sizes would be of great assistance in determining the role of myofibroblasts in idiopathic CTS.