Here’s a small addition to Dr. Jay Lozier’s Tuesday, February 1 discussion of a patient with dysfibrinogenemia whose prothrombin time (PT) was prolonged and would not correct in a mixing study.
Dr. Lozier commented as follows in a return email sent the same day:
“I thought that perhaps there would be fibrin split products that are preventing coagulation from occurring normally, but these turn out to be negative. I am getting some help from my folks at my alma mater (UNC) where Susan Lord’s group is interested in fibrinogen.”
It occurred to me it would also be interesting to learn if Beckman/IL’s QFA Fibrinogen® assay would return a more accurate result. Their reagent employs 100 units/mL thrombin instead of the 30-50 units used for the standard Clauss assay. Take a look at Dave McGlasson’s January 8 discussion of the QFA Fibrinogen assay that is designed to be used to assay fibrinogen in people who are getting direct thrombin inhibitor therapy. Dave’s discussion goes back to Kim Kinney’s question about argatroban and the fibrinogen assay posted January 5.
Finally, since Debbie Moffitt recently brought up the reptilase time test, it may be interesting to see what kind of results this test would generate on the patient’s plasma as well. I assume Dr. Lord uses this test on occasion. Geo.
Dear George,
regarding “Dysfibrinogenemia and the PT:”
PT,
Dear George,
regarding “Dysfibrinogenemia and the PT:”
PT, PTT, TT, and reptilase time would all be prolonged with a low/normal fibrinogen in dysfibrinogenemia. Since this is an isolated prolonged PT without correction, FVII inhibitor is to be suspected. (in the absence of liver disease)
Vilas Hiremath