Expression of keratinocyte growth factor (KGF) and its receptor in a middle-ear cavity problem.

OBJECTIVES To investigate the pathogenesis of one of the most troublesome conditions following ear surgery, a middle-ear cavity problem. METHODS Keratinocyte growth factor (KGF) and its receptor (KGFR), the ratio of proliferating epithelial cells using Ki-67, and the extent of infiltration of B cells and T cells were examined immunohistochemically in 10 ears with a cavity problem, 70 ears with cholesteatoma and 8 ears with normal skin at the retroauricular incision. RESULTS KGF was positive in 40% of cavity problem specimens, 37.5% of normal skin specimens, and was positive in 88% of cholesteatoma specimens (cavity problem vs. cholesteatoma, p=0.0004). The positive rate of KGFR in the cavity problem group (33.3%) was between those in cholesteatoma (60%) and normal skin (0%). In contrast to the cholesteatoma specimens, a significantly smaller number of Ki-67 labeling index (LI) was detected in the cavity problem specimens. B cell LI was significantly higher but T cell LI was significantly lower in the cavity problem specimens than in the cholesteatoma group. CONCLUSIONS Our present study indicated that the discordance of paracrine action between stromal KGF and epithelial KGFR with a large number of infiltrating B cells may play an important role in the pathogenesis of a cavity problem.