George has been communicating with Drs. Elaine Keohane (Rutgers) and Larry Smith (Abbott) about how long to wait after a thrombotic event to collect a specimen for a thrombosis risk profile. Thrombosis risk profiles include assays for antithrombin, protein C, and protein S deficiencies, which can’t be accurately measured during periods of acute inflammation (such as just after a thrombotic event), or during anticoagulation therapy. Caregivers often order profiles from inpatients who are just beginning treatment for deep venous thrombosis or pulmonary emboli; however the results from specimens collected at thet time are consistently inaccurate. Published guidelines, usually based on the Coumadin clearance interval, usually specify 7 days, 10 days, or 14 days, however Dr. Smith found a statement in Heit J, Thrombophilia, clinical and laboratory assessment and management, in Kitchens CS, Kessler CM, Konkle BA. Consultative Hemostasis and Thrombosis, Third Edition, Elsevier, 2013 that says, “Acute thrombosis can transiently reduce the levels of antithrombin and occasionally protein C and protein S. A delay of at least six weeks after acute thrombosis…allows sifficient time for acute phase reactant proteins to return to baseline.” Our discussion led us to post a November, 2017 Quick Question “When should you perform an antithrombin, protein C, and protein S profile?.” We look forward to compiling your answers in December.