Inhibition of PV RBC adhesion to HUVECs or α₅ chain laminin by mAb against Lu/BCAM measured under flow conditions. (A) Anti-Lu/BCAM inhibited the adhesion of PV RBCs to HUVECs at different shear stresses, and the inhibition at 0.07 Pa is highly significant (***P < .001; n = 6). (B) When HUVECs were replaced by α₅ chain laminin, a known ligand of Lu/BCAM, anti-Lu/BCAM inhibited PV RBC adhesion (***P < .001; n = 6). (C) α₅ chain laminin expression by HUVECs visualized by immunofluorescence and confocal microscopy. Top panel x-y horizontal plane and bottom panel x-z vertical section (magnification, × 100 000) exhibited the presence of α₅ chain laminin at the cell membrane on apical and basal surfaces. No staining was visible with an isotype-matched mouse IgG2a. Bars denote SEM.