The July issue of Clinical Chemistry presented a well-written case of combined factor V and VIII deficiency: Khani F, Roshal M. A 24-year-old man with previously diagnosed hemophilia. Clin Chem 2012;58:1086–90. Drs. EM Van Cott and JN Huang added commentaries.
I noted the recommendation for plasma to replace factor V and posed this question: Dr. Khani, thank you for your case study in the July issue of Clinical Chemistry. As an alternative to fresh frozen plasma (FFP), would you recommend platelet concentrate as a means for delivering adequate doses of factor V, in view of the high concentration of factor V in platelets? Thank you.
I received this helpful answer from the author: “Thank you for reading our article and for your excellent question. To our knowledge, platelet transfusions are a standard of care for those who have factor V inhibitors because indeed they do carry a lot of FV in the alpha granules and have an added benefit of protecting it from plasma-based inhibitors. In theory, inhibitors have much less time to react once platelets release factor V at the location of clotting. The importance of platelet factor V is demonstrated by bleeding in patients with Quebec abnormality where platelet factor V gets proteolyzed in the alpha granules. As for treating FV deficiency with platelets, one has to balance the risk of developing HLA antibodies, cost, and efficacy in comparison with FFP. It appears that FFP is still standard of care for FV deficiency without inhibitors. It is also likely the the combined FVIII and FV deficiency patients would be less likely to develop inhibitors as they have been exposed to autologous normal FVIII and FV.”
I’m curious if any of our participants uses platelet concentrate for factor V deficiency or for therapy when factor V inhibitors are present. Geo.