From Allen Quigley, Hematology/Coagulation Technical Specialist, Children's Hospitals and Clinics of Minnesota. George, what is the best way to measure factor VIII and IX levels on patients that are being infused with different products? We perform one stage clotting assays using Actin FSL, which is an ellagic acid activator, and other labs may use reagent systems that have silica activators. Depending on the product being infused, especially with factor IX (Idelvion, Alprolix) the results could be biased lower by 25-50%. Would chromogenic assays help for factor VIII? I don't think there are any approved for factor IX at this time. Thanks, Al.
Posts - Bleeding Disorders
Sep 29, 2017 3:23pm
Aug 17, 2017 1:22pm
Although the FDA approved CSL-Behring's RiaSTAP, human plasma-derived fibrinogen concentrate in 2009, it seems most facilities continue to use cryoprecipitate to treat hypofibinogenemia, dysfibrinogenemia, and afibrinogenemia. Has your institution switched to RiaSTAP? Why, or why not?
Aug 12, 2017 10:35am
From Sharon Johnson, Sysmex America: Hi George: I was recently asked if guidelines or clinical recommendations had changed for VWF normal ranges based on blood group. In CLSI Guideline H-51A. 2002, it suggests laboratories establish their own reference ranges for VWF for “O” and “Non-O” blood groups, as patients with group “O” typically have much lower normal values. Is there another or newer clinical guideline from ISTH or another hemostasis group that supports one reference range for all blood groups? I’d appreciate insights from your readers and contributors on this subject.
Jun 29, 2017 7:38am
Dr. Ali Sadeghi-Khomami, Precision BioLogic Inc., provided these in-depth technical questions about the Nijmegen Bethesda Assay (NBA), which we use to quantitate specific factor inhibitors such as anti-factor VIII or anti-factor IX. George forwarded his questions to Connie Miller and Amanda Payne, US Centers for Disease Control and Prevention (CDC ) who have been working on NBA accuracy and precision upgrades for several years. Here are Dr. Ali's questions and answers provided by Drs. Miller and Payne; thanks to all for your support.