INTRODUCTION: The purpose of the study was to test a hypothesis that the keratinocyte growth factor (KGF) is a key factor in the pathologic difference between cholesteatomatous (C-COM) and noncholesteatomatous chronic otitis media (NC-COM). We compared the expression levels of KGF and its receptor (KGFR) and the proliferation activity of epithelial cells between NC-COM and C-COM. METHODS: The epithelial lesion was surgically excised with subepithelial tissue from 18 patients with NC-COM and 70 patients with C-COM, and was processed for immunohistochemistry for KGF and KGFR. We also examined the proportion of proliferating epithelial cells using Ki-67 and the extent of infiltrating B and T cells. RESULTS: Keratinocyte growth factor was positive in 5 of 18 (28%) NC-COM specimens and in 61 of 69 (88%) C-COM specimens (p < 0.0001). Furthermore, 37 (60%) C-COM specimens were positive for KGFR, but none of NC-COM were positive (0%; p < 0.01). The Ki-67 labeling index (LI) was significantly smaller in NC-COM than in C-COM (p < 0.001). B-Cell LI was almost similar in the 2 groups. T-Cell LI was significantly higher in C-COM than in NC-COM (p < 0.0001). Interestingly, T-cell LI in NC-COM was higher in KGF-positive tissues than in KGF-negative tissues (p < 0.05). CONCLUSION: The results indicated that coexpression of KGF and KGFR seems to explain the pathologic difference between C-COM and NC-COM, and that KGF may play an important role in the development of cholesteatoma.
INTRODUCTION: The purpose of the study was to test a hypothesis that the keratinocyte growth factor (KGF) is a key factor in the pathologic difference between cholesteatomatous (C-COM) and noncholesteatomatous chronic otitis media (NC-COM). We compared the expression levels of KGF and its receptor (KGFR) and the proliferation activity of epithelial cells between NC-COM and C-COM. METHODS: The epithelial lesion was surgically excised with subepithelial tissue from 18 patients with NC-COM and 70 patients with C-COM, and was processed for immunohistochemistry for KGF and KGFR. We also examined the proportion of proliferating epithelial cells using Ki-67 and the extent of infiltrating B and T cells. RESULTS:Keratinocyte growth factor was positive in 5 of 18 (28%) NC-COM specimens and in 61 of 69 (88%) C-COM specimens (p < 0.0001). Furthermore, 37 (60%) C-COM specimens were positive for KGFR, but none of NC-COM were positive (0%; p < 0.01). The Ki-67 labeling index (LI) was significantly smaller in NC-COM than in C-COM (p < 0.001). B-Cell LI was almost similar in the 2 groups. T-Cell LI was significantly higher in C-COM than in NC-COM (p < 0.0001). Interestingly, T-cell LI in NC-COM was higher in KGF-positive tissues than in KGF-negative tissues (p < 0.05). CONCLUSION: The results indicated that coexpression of KGF and KGFR seems to explain the pathologic difference between C-COM and NC-COM, and that KGF may play an important role in the development of cholesteatoma.