Phenotypic Epithelial Changes in Laryngotracheal Stenosis

Area of Science:

• Respiratory Medicine
• Pathology
• Cell Biology

Background:

• Laryngotracheal stenosis (LTS) is a complex airway disease.
• The role of epithelial changes in LTS pathogenesis is not fully understood.
• Idiopathic subglottic stenosis (iSGS) and iatrogenic LTS (iLTS) are common forms of LTS.

Purpose of the Study:

• To characterize and quantify epithelial alterations in multiple etiologies of LTS.
• To investigate the role of these epithelial changes in the pathogenesis of LTS.
• To compare epithelial characteristics between iSGS and iLTS.

Main Methods:

• A controlled in vitro cohort study design was employed.
• Endoscopic brush biopsy and cricotracheal resection samples were collected from patients with iSGS and iLTS.
• Quantitative PCR and immunohistochemistry were used to evaluate gene and protein expression of epithelial cell markers.

Main Results:

• Epithelium in both iSGS and iLTS showed reduced thickness, ciliary cells, and secretory cells compared to normal controls.
• Basal cell markers (cytokeratin 14) were significantly increased in iSGS-scar epithelium.
• Goblet cell marker (Mucin 5AC) gene expression was reduced in both iSGS and iLTS.

Conclusions:

• Epithelium in iSGS and iLTS is morphologically abnormal, exhibiting reduced thickness and altered cell populations.
• Increased basal cell expression in iSGS suggests a distinct pathological feature.
• These epithelial changes likely contribute to the common pathogenesis of fibrosis in iSGS and iLTS.