Expression of Vascular and Tissue Repair Factors in Laryngeal Granulomas

Voice abuse, chronic cough, laryngeal surgery, and tracheal intubation may lead to injury and subsequent repair/remodeling in the vocal fold mucosa. Periostin is known to be involved in airway remodeling and is also associated with various otolaryngological diseases. D-β-aspartic acid is the major isomer of D-aspartic acid found in tissues of elderly individuals. In ischemic heart disease, increased CD31 expression has been observed around cardiomyocytes during remodeling, and endothelial proliferation has been reported at these sites. In this study, we investigated the expression and role of CD31, CD34, D-β-aspartic acid, and periostin in the formation of laryngeal granulation tissue. This retrospective study involved five patients who underwent surgical treatment for laryngeal granulation tissue. The expressions of CD31, CD34, D-β-aspartic acid, and periostin in surgical samples were investigated by immunohistochemistry. Histologically, the specimens showed inflammatory cell infiltration, fibrin exudation, fibrosis, and neovascularization, but no tumor cells. No stratified squamous epithelial covering was observed. The expression of periostin and D-β-aspartic acid was also observed in the specimens. CD31-positive cells (endothelial cells) and CD34-positive cells (progenitors of endothelial cells) were observed in the specimens. Our results indicate that the overexpression of CD31, CD34, D-β-aspartic acid, and periostin may play a role in the pathogenesis of laryngeal granulation tissue, and we speculate that D-β-aspartic acid and periostin could serve as novel biomarkers and therapeutic targets for laryngeal granulation tissue.