An immunohistological study of the localization characteristics of thymus and activation-regulated chemokine in the allergic inferior turbinate mucosa with reference to the effectiveness of trichloroacetic acid treatment.

To investigate the background of the effectiveness of trichloroacetic acid (TCA) treatment, we examined the localization of thymus and activation-regulated chemokine (TARC) on allergic inferior turbinate mucosa using immunohistological methods. After obtaining informed consent, only one side of the inferior turbinate was treated with 80% (wt/vol) TCA solution under topical anesthesia using 4% lidocaine with epinephrine in 19 cases of allergic rhinitis. Among those, 17 cases did not show clinical improvement and underwent nasal septal reconstruction surgery and turbinectomy. Bilateral inferior turbinate specimens were obtained. The untreated turbinate specimens showed positive TARC findings. The positive findings were confirmed in the outer side of cytoplasm in the stratified ciliated columnar epithelium but not in the goblet cell. In the lamina propria, the glandular tissue and afew of the infiltrated lymphocytes just beneath the epithelium up to the depth of 120 microm were found TARC-positive (TARC+). The average number of positive cells in one microscopic visual field using 100x magnification was 3.97 +/- 4.04. On the other hand, the epithelium of the TCA-treated side showed positive findings only in two cases. The TCA-treated side also showed a relative decrease in infiltrated cells. Even in areas where there still were infiltrated cells, they were confirmed to be TARC-negative (TARC-) after TCA treatment. It is considered that the regenerated epithelium after TCA treatment originates from the glandular epithelium with negative TARC expression existing in the area deeper than a 120-microm level and that this immunohistological change would lead to the effectiveness of TCA treatment.