Here is our September, 2019 Quick Question with responses from 100 participants.
A 25-YO experienced chronic soft tissue bleeding and poor wound healing. His PT, PTT, and PLT count were normal. What follow-up assay is indicated?
a. Platelet aggregometry 24 (24%)
b. Factor VIII and IX assay 12 (12%)
c. Factor XIII assay 37 (37%)
d. VWD disease profile 27 (27%)
There is no wrong answer to this question. This could be a platelet function disorder with a normal platelet count that does not affect coagulation, likewise, von Wiilebrand disease in which the factor VIII level is over 30 IU/dL, thus a normal PTT result. Factor VIII and IX deficiency could accound for bleeding without being detected by the PTT if the levels are over 30 IU/dL, though unprovoked bleeding is unlikely. Factor XIII deficiency is not detected using the routine PT and PTT, as these assay detect uncrosslinked fibrin. The poor wound healing is a particular symptom of factor XIII deficiency, a clue that accounts for the largest proportion of answers.