Another from Linda Stang, Alberta Health Service: We have a patient with ‘transient, recurrent’ factor VII deficiency that I suspect is drug related. When FVII is low, protein C and factor X are normal. Patient has been as high as 1.57 u/mL and as low as 0.08 u/mL. Do you or any of your participants have any experience with this or any references? Thanks so much, Linda.
George’s initial email response was: Hello, Linda, and again thank you for your patience. While this could be a drug-related phenomenon, my first question would be, is the specimen being collected under your supervision and stored and transported at ambient temps? This could be an artifact of chilling, which may activate factor VII in an uncontrolled fashion. Because, as you report, protein C is unaffected, this is not likely due to Coumadin, which reduces protein C activity at nearly the same rate as factor VII. It may also be a sign of early liver disease, which tends to reduce factor VII before the other factors.
Linda’s June 24 response: “Thanks for the reply George, the specimen is collected and transported ambient. Our latest observation, the patient does respond to vitamin K, but response is short-lived. One of the pathologists thinks it may be a FVII carboylase recognition site (CRS) mutation, which has been described for factor IX where it is more frequently a problem because of it’s X-linked nature, but apparently is in all vitamin K dependent proteins. I would really like to test the patient ‘med-free’ but I do not think that is possible. He is on meds for post-traumatic stress, as the patient was on active duty, and lost his legs in Afghanistan. It is a interesting collection of unusual results. have a great day, Linda.
George’s July 1 response is to bring this question to some of the experts here at the ISTH meeting in Amsterdam for a consensus.
July 2: George spoke with Drs. William Nichols, Alexander Duncan, and John Olsonand learned that phospholipids bind factor VII. They recommended checking the lipid profile. Also, check timing of drug administrations to see if one correlates to the spikes and troughs of the factor VII.