Table 2. Clotting potential of severe or moderate hemophilic A or B blood when triggered by the low or high levels of contact activation or extrinsic activation in the presence and absence of rFVIIa.
Rescue indicates return to response levels of healthy blood. Low CTI: 4 μg/mL corn trypsin inhibitor; High CTI: 40 μg/mL corn trypsin inhibitor. Mild hemophilic blood (>14–15%) performs without large functional deficit when compared to healthy blood in this assay under conditions of contact or extrinsic activation with reduced sensitivity to added rFVIIa.
| Condition | Clotting at 100 s−1 | |||||
|---|---|---|---|---|---|---|
| Phenotype | Surface | Contact pathway | rFVIIa | Platelets | Fibrin | [ref.] |
| Severe (< 3%) |
Collagen | No (high CTI) | 0 | low | none | [24] |
| No (high CTI) | + | modest rescue | none | |||
| Yes (low CTI) | 0 | Low | none | |||
| Yes (low CTI) | + | slight rescue | ~none | |||
| Moderate (3–14%) |
Collagen | No (high CTI) | 0 | modest | none | [24] |
| No (high CTI) | + | rescue | none | |||
| Yes (low CTI) | 0 | modest | very low | |||
| Yes (low CTI) | + | rescue | rescue | |||
| Severe (<3 %) |
Collagen + [TF]low |
No (high CTI) |
0 | very low | none | * |
| Collagen + [TF]low | + | rescue | rescue | |||
| Collagen + [TF]high | 0 | very low | none | |||
| Collagen + [TF]high | + | rescue | rescue | |||
| Moderate (3–14%) |
Collagen + [TF]low |
No (high CTI) |
0 | modest | modest | * |
| Collagen + [TF]low | + | modest | modest | |||
| Collagen + [TF]high | 0 | moderate | moderate | |||
| Collagen + [TF]high | + | moderate | moderate | |||
*
this study.