From "Ari." Hi George, I stumbled upon your amazing site when researching this question and was wondering if you could shed some light on this. I have a patient who had a DVT. His PCP noted a slightly prolonged aPTT and sent mixing studies. From what I can tell, the aPTT mostly corrected with mix, but the PTT-LA is definitely long and only slightly corrects (basically it stays prolonged). I understand the PTT-LA results as indicative of a lupus anticoagulant (LAC ) which fits the clinical picture of DVT , but I'm having trouble understanding why the aPTT would correct on mixing. Can you shed some light on this? I've copied the relevant labs with patient identifying factors removed to this link: https://imgur.com/a/e0ubV. (Readers go to the link for the patient data, Geo.)
Posts - Lupus Anticoagulant
Nov 8, 2017 4:11pm
Apr 22, 2017 7:40am
An intriguing case from Heather DeVries, Indiana University Health. Hi George, I have an interesting (cold) case study for you. We recently tested a 44 yo female for lupus antibodies and she had textbook results--nothing equivocal about them. Her history includes a late-term pregnancy loss 12 years ago, and a recent diagnosis of lupus, so it seems that she could now be considered to have antiphospholipid antibody syndrome (APS). This is where the family history comes in.
Apr 11, 2017 8:05pm
From Wendy Sutula, Hi, George. We are validating a new vendor's ACA kit. When we perfom patient ACA tests, the serum samples are frozen at –20 for 2–7 days before tesing. When establishing or validating the reference range for the new vendor's kit, is it acceptable to use serums which have been collected and frozen within two hours of collection at –70 instead of –20, and for periods of time longer than 1 week, or must we adhere to the same storage requirements prior to testing as for the patient samples? I couldn't find a specific reference to address this in the CLSI documents. Thanks so much.
Aug 26, 2016 3:11pm
George reviewed this question posted to the American Society for Clinical Laboratory Science Consumer Web Forum: "After DVT/PE helped by TPA/heparin and now on Xarelto 4 weeks, my first blood draw shows factor VIII 228%, DRVVT