From Pam Owens: Hi George, good to see you at THSNA! (Thrombosis and Hemostasis Summit of North America). I am hearing more about how ineffective the 5M urea test is for factor XIII screening and am thinking we just need to stop doing the assay in our lab. I’ll need to convince our lab director. Are there any articles or published studies out there? I’m not having any luck looking on line.
Hi, Pam, and thank you for your question. The 5 M urea solubility assay is a “time-honored” means for measuring factor XIII but it is not particularly sensitive. I know that many lab directors have replaced it with a quantitative assay, but I’ve seen no validation studies or head-to-head comparisons. However, I’ve been able to turn up two comprehensive review articles that describe the old and new assays. Here they are: