Discrimination of ameloblastomas from odontogenic keratocysts by cytokine levels and gelatinase species of the intracystic fluids.

In the present study, we measured the levels of the cytokines and gelatinase species in the fluids of ameloblastomas and odontogenic keratocysts, and showed that ameloblastomas can be distinguished from odontogenic keratocysts by the use of these biochemical data. We found that interleukin (IL)-1alpha and IL-1beta levels in the intracystic fluids of ameloblastomas were significantly lower than those in the fluids of odontogenic keratocysts, while IL-6 levels in the fluids of ameloblastomas were significantly higher than those in the fluids of odontogenic keratocysts. On the other hand, no significant differences in tumor necrosis factor (TNF)-alpha levels of the fluids were detected between ameloblastomas and odontogenic keratocysts. An immunohistochemical study revealed that the staining intensity of IL-1alpha, IL-1beta and TNF-alpha in the tumor cells of ameloblastomas was significantly weaker than that in the epithelial cells of odontogenic keratocysts, while the staining intensity of IL-6 in the tumor cells was significantly stronger than that in the epithelial cells of odontogenic keratocysts. Gelatin zymography of the fluids showed that only a small amount of pro-MMP-9 was detected in ameloblastomas, while both pro-MMP-9 and the active form of MMP-9 were detected in 8 of 10 cases of odontogenic keratocysts. Thus, ameloblastomas can be distinguished from odontogenic keratocysts by measuring IL-1alpha and IL-6 levels, and gelatinase species in the fluids.