Comprehensive gene expression analysis using RNA sequencing between male and female patients with idiopathic carpal tunnel syndrome.

Idiopathic carpal tunnel syndrome is the most common entrapment neuropathy in hand surgery, and it is characterized by Noninflammatory fibrosis of subsynovial connective tissues. The prevalence and incidence differ between male and female individuals, and the mechanism underlying this difference remains largely unclear. In the present study, we collected subsynovial connective tissues from six male and six female patients diagnosed with idiopathic carpal tunnel syndrome during surgery. We performed a comprehensive gene expression analysis using RNA sequencing to compare the gene expression profiles between male and female patients with idiopathic carpal tunnel syndrome. We identified 26 genes with significantly different expressions between male and female patients, in which POSTN, COL1A1, and COL3A1, which are involved in extracellular matrix organization, and IGF1, an important fibrotic factor, were significantly upregulated in male patients. Immunohistochemistry confirmed the expression of proteins encoded by these genes in tissues, and male patients tended to show increased POSTN expression. Our results indicate that fibrosis of subsynovial connective tissues is induced by different mechanisms in male and female patients, and genes involved in extracellular matrix organization, especially POSTN, might be important factors in male patients. This study provides insight into the pathogenesis of idiopathic carpal syndrome and might contribute to the development of new treatment strategies.