Figure 1.

Integrin subunit β8 and β3 immunostaining in BAVMs relative to control brain samples. β8 immunohistochemical localization (A, D, G, J) was compared with β3 (B, E, H, K) and no primary antibody control staining (C, F, I, L). Shown are representative staining patterns seen in the normal insular cortex (A–C), temporal lobe from a patient with epilepsy (D–F) or from two separate BAVMs (G–L). A and D: Photomicrographs demonstrate the presence of perivascular β8 staining adjacent to small cerebral vessels (V) or in G and J, absence of staining in the perivascular cell processes surrounding the walls of large BAVM vessels (VW) or small perinidal BAVM vessels (v) vessels. Scale bar = 50 μm in A–C, G–L) and 25 μm in D–F. Shown in A and D are photomicrographs of small vessels with perivascular staining tracing the outer wall of the vessel (white arrows), which is absent from BAVM samples (G and J, black arrows). Diffuse β8 immunostaining of the neuropil is shown in both control (A and D) and BAVM (G and J) samples. β8 neuropil staining tended to be lighter in BAVM samples. Little or no staining is observed in samples stained with anti-β3 (B, E, H, K) or no primary antibody controls (C, F, I, L).