Relation between mast cell and microvessel dentisities in reactive lesions of the oral cavity

Abstract

Oral reactive lesions which are reactive hyprplasias of connective tissues are the most common lesions of the oral cavity. The precise role of mast cells and angiogenesis in these lesions is not defined. Purpuse of study:The purpose of this study was to investigate mast cells and micro vesssels densities in these lesions and compare these items in different reactive lesions. Also we evaluated the correlation between mast cells and microvessels in reactive lesions to clarify the role of these cells in angiogenesis and these lesions growth. Methods: In this cross-sectional study, 75 samples, including irritation fibroma (IF), inflammatory fibrous hyperplasia (IFH), peripheral giant cell granuloma (PGCG), peripheral ossifying fibroma (POF) and pyogenic granoluma (PG) categories (15 for each), were selected . Fiftheen normal gingival tissues were considered as the control group. Immunohistochemical staining was performed using anti-mast cell tryptase and anti-CD31 to evaluate mast cells and angiogenesis . The number of mast cells and micro vessels were counted in 5 high power fields ( 40) beneath epithelium and 5 high power fields ( 40) in depth of connective tissue containing maximum counts for each sample . A total mean (the mean of beneath epithelium and depth of connective tissue ) were counted to obtain mast cells and microvessels densities in each sample. Data were analyzed statistically, and p values <0.05 were considered statistically significant. Results: . Mast cell counts were significantly increased in IFH and POF groups compared to other groups(P value <0.05) . CD31 expression counts were increased in IFH and F groups (P value <0.05). A significant reverse correlation was seen between CD31 expression and MC count in the oral reactive lesions (P value <0.05). Mast cell and CD31 expressions were increased under epithelium compared to depth of connective tissue . These increases were statistically significant for mastcell tryptase expression in POF ,PGCG and F groups and for CD31 expression in PG ,PGCG, F and control groups (P value <0.05). Conclusion: Inspite of presence of mast cells in oral reactive lesions , these cells do not play an active role in the growth of these lesions, because of the reverse correlation between mast cells and angiogenesis in oral reactive lesions ; so we can not use mast cell inibitors for treatment purposes