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Date of last update: 10/20/2017.

Forum Name: Clots & Anticoagulants

Question: F5 Leiden Homozygote - test reliability?

 LauraL - Sat Sep 06, 2008 12:52 pm

Hi there. I am a 44 year old woman recently diagnosed, first time, with a large DVT. I had blood work done with results that came back positive for F5 Leiden homozygous, also presence of a Lupus anitcoagulant.
My question is, they drew my blood after I had already started on Lovenox and coumadin (2 days, 5mg coumadin 1x day, 60 ml lovenox 2xday). Would that skew the test results? The test (I think it's called Analyte Specific Reagent?) was developed by the Laboratory Medicine and Pathology, Mayo Clinic. I thought only a gene test could determine if the F5 Leiden mutation was either homo or heterozygous? I have a copy of the results, and the note says "this individual DOES have the factor V Leiden R506Q mutation on BOTH alleles"...should I get tested again, or is my next step to go to a hematologist?
Your help is greatly appreciated!
 John Kenyon, CNA - Sat Oct 04, 2008 10:35 pm

User avatar Hello -

It would seem conclusive that you do, in fact, have Factor V Leiden as determined by the ASR test, which is a genetic test and is not skewed by having anticoagulant drugs on board. In fact, that's probably why this test was performed intead of (or in addition to) the activated protein C resistance test, which can be skewed by the presence of anticoagulant medications.

The good news is you can know this and manage the disorder and likely avoid any serious future problems. A hematologist is definitely your next stop.

Best of luck to you. Please follow up with us as needed.
 LauraL - Tue Oct 07, 2008 5:39 pm

Thank you for your reply. I have seen a hematologist, and you're right, the FVL test was indeed an accurate, genetic test. The lupus anticoagulant, on second testing, was no longer present, so I'm not sure why it showed up on the first test. Anyway, the hematologist called my blood "boring" and that's a relief! I do have another question regarding therapy I'll put in a separate post. Thanks again!
 John Kenyon, CNA - Wed Oct 08, 2008 1:22 pm

User avatar You're welcome.

"Boring blood" is a wonderful thing. As for the amazing disappearing lupus anticoagulant, this happens on occasion for reasons not entirely clear to me. It certainly is preferable to a positive second test.

Thanks for the follow up. Good news. I'll be on the lookout for your other post. Thanks for bringing your questions to this site.

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