Mast cells as key players in periodontal disease

Abstract

Mast cell (MC) active mediators promote inflammation through changes induced in the connective tissue components of human gingiva. The aim of this study was to evaluate the distribution, mast cell density and their relationship with the degree of inflammatory infiltrate in gingiva from patients with periodontal disease. Thirty-nine cases with periodontal disease and 12 cases without significant changes to the gingival mucosa were investigated. MCs were identified on paraffin-embedded specimens by immunohistochemistry using anti-mast cell tryptase. The inflammatory infiltrate was scored from 0 to 3, and the MCs were counted using the hotspot method. Intraepithelial MCs were scored from 0 to 2. We found a significant increase of mast cell density in cases with mild and moderate inflammatory changes, and a slight decrease in patients with severe periodontal disease. We noticed a higher degranulation rate in patients with periodontal disease compared to those with healthy mucosa. Intraepithelial MCs were found in cases with periodontal disease only and were correlated with the severity of the inflammatory lesion. MCs are important cellular components of the early stages of periodontal disease. Contrary to other studies, we found that MC density and activation increases with moderate inflammation but decreases in severe inflammatory lesions. Our data suggest that MCs are key players in the progression of inflammatory lesions of the gingiva. In advanced-stage periodontal disease, intraepithelial MCs apparently play an important role, although their biological significance remains to be fully understood.