Increased TNF-α, IL-6 and decreased IL-1β immunohistochemical expression by the stromal spindle-shaped cells in the central giant cell granuloma of the jaws

Objectives: the exp ress ion of the osteoclastogenic cytokines TNF-α, IL-6 and IL-1β were immunohistochemically evaluated in periph eral (PGCG) and central (CGCG) giant cell granulomas of the jaws in order to determine diff erences between these two lesions and between the two distinct tumor cell populations (multinucleated giant cells, MGCs and stromal sp indle-sh aped cells). Study Design: Paraffin-embedd ed tiss ue sections from 40 PGCG and 40 CGCG were immunohistochemically stained using antibodies against TNF-α, IL-6 and IL-1β. The percentage of positively stained cells and the staining intensity were ass ess ed to provide a combined immunoreactivity score value. Results: TNF-α, IL-6 and IL-1β were exp ress ed in all lesions. The CGCG compared to the PGCG sh owed significantly increased exp ress ion of TNF-α and IL-6 and decreased exp ress ion of IL-1β by the sp indle-sh aped cells and increased exp ress ion of IL-1β by the MGCs. The MGCs demonstrated in comparison to the stromal sp indlesh aped cells significantly increased exp ress ion of all three cytokines in both PGCG and CGCG. Conclusions: The proinflammatory cytokines TNF-α, IL-6 and IL-1β seem to be involved in the growth process of PGCG and CGCG of the jaws. A poss ible alteration in the sy nthesis or/and activity of these cytokines by the stromal sp indle cells in the CGCGs may enhance osteolys is through the stimulation of osteoclast progenitor cells, given the fact that the intraoss eous lesions cause bone resorption. Key words: Giant cell granuloma, giant cell tumor, multinucleated giant cells, jaw, TNF-alpha, IL-6, IL-1beta, immunohistochemistry.