Fresh Frozen Plasma Contains von Willebrand Factor
Yes, fresh frozen plasma (FFP) contains von Willebrand factor (VWF) as part of its soluble coagulation factor content. According to the AAGBI blood transfusion guidelines, FFP contains all the factors of the soluble coagulation system, including the labile factors V and VIII to a varying degree 1.
Composition of Fresh Frozen Plasma
Fresh frozen plasma is leucodepleted plasma that is rapidly frozen to below -25°C to maintain the integrity of labile coagulation factors. It contains:
- All soluble coagulation factors
- Labile factors V and VIII
- von Willebrand factor
- Fibrinogen (approximately 2g in four units of FFP)
- Other plasma proteins
Comparison with Cryoprecipitate
While FFP does contain VWF, it's important to note that cryoprecipitate contains a more concentrated amount of VWF. The AAGBI guidelines specifically state that cryoprecipitate is a "leucodepleted plasma product containing concentrated factor VIII, von Willebrand factor, fibrinogen, factor XIII and fibronectin, produced by further processing of FFP" 1.
This means that:
- FFP contains VWF, but in lower concentrations
- Cryoprecipitate contains a more concentrated form of VWF
- For clinical situations requiring significant VWF replacement, cryoprecipitate may be more effective
Clinical Relevance
The presence of VWF in FFP has important clinical implications:
- In patients with thrombotic thrombocytopenic purpura (TTP), FFP infusions can provide the VWF-cleaving protease (ADAMTS13) that is deficient in these patients 2
- In von Willebrand disease, while FFP contains VWF, research suggests that cryoprecipitate achieves higher increases in VWF levels compared to FFP 3
- Studies have shown that FFP can affect VWF multimeric forms in patients with chronic relapsing TTP 4
Important Considerations
When using FFP for its VWF content:
- The recommended therapeutic dose of FFP is 15 ml/kg 1
- FFP should be ABO compatible with the recipient
- If blood group is unknown, group AB FFP is preferred as it doesn't contain anti-A or anti-B antibodies
- FFP can be thawed using a dry oven (10 min), microwave (2-3 min), or water bath (20 min)
- Once thawed, FFP can be used for up to 24 hours if stored at 4°C (extended to 5 days for major hemorrhage associated with trauma)
- Once out of the refrigerator, it must be used within 30 minutes
For patients specifically requiring VWF replacement (such as those with von Willebrand disease), cryoprecipitate or specific factor concentrates may be more appropriate than FFP due to their higher concentration of VWF 1, 3.