Effect of anti-A2 Ab on TF activity induced by IgG-APS in HUVECs. HUVECs were cultured and treated with either IgG-APS or IgG-NHS in the presence or absence of anti-A2 MoAb, as indicated in “TF functional assay.” Some cells were treated with LPS, as a positive control, or with medium alone, as a negative control. TF activity was determined using a chromogenic assay, and data expressed as fold increase (mean ± SD) over the corresponding control. Experiments were performed 3 times in duplicate. ¶Statistically different from medium-treated cells (P = .031). *Statistically different from IgG-NHS–treated cells (P = .015). **Statistically different from IgG-APS–treated cells (P < .044; P < .05).