Characterization of the Integrin alpha v beta 3 in Arteriovenous Malformations and Cavernous Malformations

Background: Alpha V beta 3 ( alpha v beta 3) is an integrin specifically expressed on the endothelial cells of central nervous system (CNS) neoplasms. However, no data exist on the expression of alpha v beta 3 in vascular malformations of the CNS. In this study, we investigate the expression of alpha v beta 3 in arteriovenous malformations (AVMs) and cavernous malformations (CMs). Method: Frozen samples of AVMs from 12 patients and CMs from 5 patients were obtained intraoperatively. Once the final pathology had been confirmed, immunohistochemistry was performed using an antibody to the integrin alpha v beta 3. The alpha v beta 3 expression pattern was graded according to the percentage of positively staining vessels. Results: Ten of 12 AVMs demonstrated alpha v beta 3 immunopositivity. Six of these 10 AVMs had moderate or strong staining. Most notably, 5 of the 6 moderate or strongly staining AVMs came from patients 22 years of age or younger. Four of these 6 AVMs had previously been embolized. None of the cavernous malformations demonstrated alpha v beta 3 immunopositivity. Discussion: alpha v beta 3 may contribute to the formation of AVMs in younger patients. alpha v beta 3 may also provide a potential therapeutic target. The lack of alpha v beta 3 expression in cavernous malformations, despite their high vascular densities, suggests that the pathophysiology of their formation differs from that of AVMs. Copyright [copy 2005 S. Karger AG, Basel