PMC8787104_01
PMC8787104_02
Shows a representative Bethesda assay graph for plotting the calculated residual VWF:RCo % activity, to derive the inhibitor titer in Bu/ml, which is then multiplied with the dilution factor to obtain the final VWF inhibitor titer in Bu/ml.
fmed-08-807664-g0001.jpg
PMC8787104_02_fmed-08-807664-g0001.jpg
F1
Therefore, the patient's value of 5.4% corresponds to 50 x 5.4 / 8 = 33.75% (residual VWF:RCo activity), and has obtained the corresponding Bu/ml value of 1.7 from the graph (Figure 1). The 1.7 x dilution factor of 128 = 217.6 Bu/ml was the VWF:RCo inhibitor Bethesda level of the Case 1. Therefore, the patient's value of 7.5% corresponds to 50 x 7.5/8.7 = 43.10% (residual VWF:RCo activity), and has obtained the corresponding Bu/ml value of 1.2 from the graph (Figure 1).