From Vanessa Chan, Sick Kids Hospital in Toronto: Hi George, Do you have any information on how PEG-ylated drugs (PEG-ylated to increase the half life of the drugs) may affect clotting assays? Thanks! Vanessa.
Hi, Vanessa, While I have heard that polyethylene glycol (PEG) in drugs can affect the phospholipid structures in prothrombin time (PT) thromboplastin reagent and partial thromboplastin time (PTT) reagent, and have seen some unexpected laboratory results that have caused us to suspect PEG, I can find no reference that confirms or rejects the idea. I’m at the Quest meeting in DC and just asked a couple of folks on the exhibit floor, including Dr. Jeff Dlott of Quest, and we all seem to have the same experience. Maybe someone else out there can help, but meanwhile, I will do a little more asking.