Treatment

This patient with very low factor V (FV) activity is bleeding into his leg. Which of the following therapies is/are appropriate?

Although the mixing study did not show evidence of an inhibitor towards factor V (FV), there is concern that there is a clearance-enhancing antibody against FV. What is a reasonable treatment strategy to eradicate the inhibitor (more than one answer may be correct)?

This patient was treated as follows:

• Packed red blood cells 17 units over 17 days
• Fresh frozen plasma 18 units over 17 days
• Platelets 19 units over 17 days
• Prednisone 1 mg/kg/day for 21 days, then tapering doses

The following is his time course:

As can be seen from the data in the previous slide, the patient’s FV activity level increased, and his PT and aPTT decreased over the ensuing 17 days while being treated with high dose prednisone (to reduce inhibitor level), fresh frozen plasma and platelets (to increase the FV level), and packed red cells to replace blood loss from the muscle hematoma (he also developed some GI blood loss, which contributed to the anemia).

The following is the time course for serum haptoglobin and an unknown serum marker: