Effect of Systemic Steroid on the Expression of TGF-beta and IL-10 in Nasal Polyps

Lee, Seung Sin; Go, Young Min; Bae, Jung Ho; Cho, Keun Kyung

Abstract

BACKGROUND AND OBJECTIVES: Etiology and pathogenesis of nasal polyps are still not fully understood. Transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) are important cytokines for nasal polyp formation and immunomodulation. This study was aimed to evaluate the effect of systemic steroid, which is the most potent medications used for the treatment of nasal polyposis, on the expression of TGF-beta and IL-10 in nasal polyps.
SUBJECTS AND METHOD
According to the status of steroid treatment, the polyps (n=22) removed during an endoscopic sinus surgery were divided into treatment or control groups. For treatment group, 30 mg of prednisolone per day was administered preoperatively for seven days. Eosinophil infiltration, expression and concentration of TGF-beta1 and IL-10 in nasal polyps were analyzed.
RESULTS
Although there was no statistical significance, the infiltration of eosinophils decreased in the treatment group. In the immunohistochemical study, the expression of TGF-beta1 decreased in the epithelial layer of the treatment group compared with that of the control group (p=0.043). Expression of IL-10 increased in the stromal layer of the treatment group compared with that of the control group (p=0.008). TGF-beta1 concentration measured by ELISA showed no differences between each group. IL-10 concentration increased in the treatment group (p=0.021).
CONCLUSION
These findings suggest that systemic steroid may exert a beneficial effect on nasal polyp treatment by at least following two mechanisms : the suppression of epithelial differentiation and proliferation, and squamous metaplasia through the down regulation of TGF-beta, and the down regulation of inflammatory responses by increasing IL-10.