Impact of VWF on FVIII-IC formation. Sedimentation coefficient distributions were obtained as described in Figure 1, with the exception that antibodies and VWF were used as follows: (A) rhFVIII and Ab1-7 (green trace) compared with rhFVIII incubated first with VWF and then with Ab1-7 (red trace); (B) rhFVIII with Ab1 only (green trace) compared with rhFVIII incubated first with VWF and then with Ab1 (red trace); (C) rhFVIII and Ab2 only (green trace) compared with rhFVIII incubated first with VWF and then with Ab2 (red trace); (D) rhFVIII incubated first with VWF and then with Ab1-7 (red trace) compared with rhFVIII incubated first with Ab1-7 and then with VWF (blue trace); (E) rhFVIII incubated first with VWF and then with Ab1 (red trace) compared with rhFVIII incubated first with Ab1 and then with VWF (blue trace). The free IgG fraction is marked by an asterisk.