Lupus Anticoagulant testing while on Warfarin

[Raw57]

I have searched the group but I do not seem to find what I need to know. If your hematologist insist on testing for Lupus Anticoagulant how many days must you stop warfarin before the test? The hematologist says that the DVRTT test works without stopping Warfarin. But I have read many times that while on an anticoagulant you might receive false positive results. I have not questioned her much beyond mentioning that I have read this happens. Thank you for any information.

[Moorey2]

I did mine recently whilst still on warfarin

[GillyA]

Hi, with a very specialised lab you can test while on warfarin using a Taipan snake venom and ecarin test. I’ve never heard of being able to do the normal LA test on warfarin. I think most haematologists would not stop warfarin for the sake of the test, although if essential you could bridge I think.

I had the specialist test done at UCLH in London.

[Ageingfemale]

hiya, I live in Warwickshire and when I was first being tested for APS the haematologist told me there was a special test to have whilst still remaining on warfarin that involved snake venom and the only place that it seems to be available is London. I went to Guys and St Thomas (right opposite the Shard) hospital. Hope this helps.

[Raw57 in reply to Ageingfemale]

That is the test she ordered. Thank you for your reply.

[Mermaidatheart]

I have never stopped warfain when being tested. Not been a problem

[maejane]

hi, I am positive aps lupus anticoagulant. I had to retest 12 Weeks later.

I was on pradaxa after reclotting on rivaroxaban. I had to stop for 5days before the test.

I was positive again on my 2nd Test.

Allergic to warfarin, so put onto phenindione.

[diane1428]

I had my test on warfarin no problems

[hihannula]

I did not know that, while on warfarin, the LA test could be a false positive. I'm sure the labs in Canada do not use snake venom, so my LA test is most likely not accurate.

[Raw57]

Thank you for your reply. I did find a research paper on it that said that the DVRTT would give reliable results on Warfarin. I did get it done and it is positive, high positive. I see the hematologist next week. I will see what she says. I was curious. The only other time I was tested for LA was in 2017. The results were 1.2 in all 3 categories. I was told that was not really positive by my then hematologist. Now the results are 1.6, 2.66 and 1.6. It does not really matter in the long run I suppose. I have APS. That will not change.

[KellyInTexas Administrator in reply to Raw57]

( oh- just seeing this. )

[KellyInTexas Administrator]

Never stop warfarin.

There are two ways to test for the LA while on warfarin:

1. A top hematologist who specializes in APS can test by adding in an extra step - Prof Hannah Cohen did this with my blood. I’d have to pull my labs .

2. By offering a chromogenic factor x test I think it is. University of Michigan does this and San Antonio heme does this. You compare it with INR. If there is a bid discrepancy- you know the LA accounts for the difference. Mine was present some days, some days not. Mine was present about 50% of the time.

Never never stop warfarin. You must have a hematologist who knows how to test around the warfarin.

[Raw57]

I did not stop. I just did the test as ordered. Hopefully it was not a complete waste of time and money.

[Yodel]

I am really pleased to have seen this post and the replies. One of my consultants wanted to a lupus test but I opted out when I knew I needed to stop warfarin for some time before the test (I originally was diagnosed with APHS after a stroke).

[Raw57 in reply to Yodel]

I believe it is possible to test for it while on warfarin. The hematologist must know how to order the test and the lab must be aware you are taking warfarin.

[Yodel in reply to Raw57]

Thanks Raw7. I saw from the responses that this is an option. I will ask the consultant next time I see her.