Expression of leukocyte adhesion molecules in blood versus cantharidin skin blisters. Granulocytes, monocytes, and lymphocytes in blood and blister fluid, gated according to the strategy defined in Figure 1, were analyzed flow cytometrically for expression of LFA-1 (A), Mac-1 (B), VLA-4 (C), and L-selectin (D). Results are expressed as the mean ± SD mean fluorescent intensity (MFI) of staining from n = 9 individuals. NS indicates not significant.