I [Geo] am preparing an audio PowerPoint module describing the primary coagulation assays, PT, PTT, TT, and fibrinogen [Fg] assays. I asked several colleagues if we continue to encounter factor V inhibitors. Before ~2010 we encountered anti-FV and sometimes anti-FV plus anti-FII [prothrombin] as cross-reacting antibodies that arose in response to bovine thrombin used in a surgical sealing material sometimes called “fibrin glue.” We agreed that all the fibrin glue products now available employ human thrombin, either plasma-derived or synthetic and that we are no longer encountering these inhibitors.
I did find, however, a series of three case studies documenting one congenital factor V deficiency treated with platelet concentrate and two factor V inhibitors that formed subsequent to piperacillin- tazobactam or ciprofloxacin exposure, attached. I’m curious to learn if any of our participants have recently found patients with factor V inhibitors.