From Crystal Azevedo, “Are there any substances known to interfere with the neutralization of heparin by the Dade (Siemens) Hepzyme product? We recently worked on a patient sample that I am told had absolutely NO heparin in it, yet the PTT decreased from >200 seconds to 89 seconds after treatment. Thanks!”
Hi, Crystal, and thanks for your question. Just when I think we’ve seen it all, something new and interesting comes along. I knew of nothing other than heparin that is either digested by Hepzyme or neutralized by polybrene, so I sent your question on to Drs. Jon Geske and Ali Sadeghi Khomami, leaders of the science team at Precision BioLogic. Ali responds, “I have never come across a condition like this. Is it possible that either LMWH or fondaparinux are on board, since these heparin-like materials are easily neutralized by Hepzme. On the other hand, an updated list of interfering reagents with a product such as Hepzyme is not always available due to market considerations. So, answering this question is difficult.”
So in response, no, this is a new one on us, unless it is LMWH or fondaparinux (which generally don’t prolong the PTT to >200 seconds.
-Ali
It might be an effect of heparin-like molecules (endogenous
It might be an effect of heparin-like molecules (endogenous heparinoids), frequently seen in patients with hepatic problems:
McKee RF, Hodson S, Dawes J, Garden OJ, Carter DC. Plasma concentrations of endogenous heparinoids in portal hypertension. Gut 1992;33:154952.
Zambruni A, et al. Endogenous heparin-like activity detected by anti-Xa assay in infected cirrhotic and non-cirrhotic patients. Scand J Gastroenterol 2004;39:8306.
Senzolo M. Heparin-like effect in liver disease and liver transplantation. Clin Liver Dis. 2009;13:4353.
Thanks to Vadim Kostousov for this extremely helpful information. (Geo)