Anti-PDI antibodies inhibit adhesion of platelets to GFOGER-GPP but not CRP. (A) Washed platelets were incubated with 0.5% dilution of monoclonal antibody RL-90 or control ascites, as indicated, then allowed to adhere to GFOGERGPP (▪) or CRP (□). Residual adhesion after 45 minutes was measured as described in “Methods,” using adhesion method A. Data represent mean ± SD of 2 separate experiments, each measured in duplicate. (B) Platelets were incubated for 20 minutes with Fab fragments of either polyclonal anti-PDI or control IgG (400 μg/mL), then allowed to adhere to GFOGER-GPP (▪) or CRP (□). Residual adhesion after 1 hour was measured as described in “Methods,” using adhesion method B. Data are mean ± SD of 3 experiments, each measured in triplicate (P < .01).