Transforming growth factor and neutralizing antibodies in subglottic stenosis

Transforming growth factor beta 1 (TGF-beta1), which is implicated in the pathogenesis of fibrotic diseases such as interstitial fibrosis, may be associated with subglottic stenosis. To study this hypothesis, we measured TGF-beta1 expression sequentially in 28 rats after posterior cricoid injury, using both standard immunohistochemistry and reverse transcriptase-polymerase chain reaction. In addition, an osmotic pump infused TGF-beta1 in 18 rats, normal saline solution in 9 rats, and neutralizing antibodies in 9 rats. Specimens were stained for fibronectin and procollagen at 1, 7, and 21 days and underwent optical density analysis. In the injured airway, TGF-beta1 expression peaked at 1 day and returned to baseline by 21 days. The TGF-beta1 infusion led to an increase in the expression of extracellular matrix proteins relative to controls. In contrast, neutralizing antibodies led to a decrease in extracellular matrix protein expression. These findings suggest that TGF-beta1 may possibly play a role in the pathogenesis of subglottic stenosis.