The potential role of CD31 and Bcl-2 in the etiopathogenesis of oral pyogenic granuloma

Pyogenic granuloma (PG) is a vascular reactive lesion of the oral cavity which is caused by local trauma or irritation and has a distinct biological behavior. Up till now, the pathogenesis of PG is not adequately understood.
Aim: Assessment of the expression of CD31 and Bcl-2 in PG to clarify the etiopathogenesis of this lesion and to determine whether vascular proliferation in this lesion has a relation to its apoptotic status.
Materials and Methods: 4μm sections were prepared from paraffin-embedded blocks of PG (20 samples) and normal gingiva as a control (10 samples). Staining of each specimen with hematoxylin and eosin (H&E), CD31 and Bcl-2 was done.
Results: all lesions of PG showed positive CD31 and Bcl-2 immunostaining in the endothelial cells of blood vessels and in the stromal ovoid cells. Control group showed positive CD31expression in the endothelial cells of blood vessels while Bcl-2 expression revealed positive expression mainly in the basal cells of the epithelium. A significant higher expression of CD31 and Bcl-2 was detected in PG than normal gingiva. A strong positive correlation was found between CD31 and Bcl-2 area percent of immune-expression.
Conclusions: The data of the present study suggest a role of Bcl-2 overexpression in the potentiation of angiogenic response and support the role of CD31 and Bcl-2 in the etiopathogenesis of PG.