Positive lateral flow tests and negative PCR - is it my medication?

[Dotty58]

Hello, I’m new to the NRAS community but not new to RA. I’m still working my way through different medications to find one that works for me, but for the past 12 months I’ve been on Sulphasalazyn.

I’m after some advice/ guidance please

4 weeks ago as a result of being really poorly, and unable to see or communicate with my RA team or consultant, my GP put me on a reducing course of Prednisolone (finished today 6/11/21). 2 weeks ago I finally saw my RA team and a new prescription of Hydroxychloroquine was issued. This means that for the past 2 weeks I’ve been taking Sulphasalazyn, Prednisolone and Hydroxychlorquine. I woke up one morning 10 days ago feeling a bit poorly, so as a precaution I took a lateral flow test which indicated a very clear positive. I immediately arranged a PCR which came back negative. I’ve not had any of the COVID symptoms (cough, loss of taste/smell, temp) but have experienced minor headaches and random chills). Over the past week I’ve done subsequent lateral flow tests (all positive) and 3 PCR tests (all negative). I self isolated for 10 days in case ‘coronavirus’ was developing but my last PCR 2 days ago was negative

Has anyone had any similar. experience of this?

Is there any research that might help me understand what’s happening?

I’m beginning to think my medication has affected the results of my lateral flow tests.

Any advice, knowledge or pointers would be gratefully appreciated.

[Lolabridge]

It’s more likely your PCR tests went to the lab in Wolverhampton where they said many results were negative when indeed they were actually positive. It’s been reported in the media and press.

Well done for assuming you were positive and self isolating for 10 days. Your headaches and sniffles could well be Covid if you’ve been vaccinated - these are the top two symptoms now in people who have been vaccinated.

I suggest you do another lateral flow test and if that’s also negative assume you no longer have Covid.

[bpeal1 in reply to Lolabridge]

I agree that it’s likely your PCR was possibly done at the dodgy lab in Wolverhampton. However, be aware that lateral flow tests can show as positive for up to 90 days after infection. People who take lateral flow tests regularly for work or school are advised not to use them for 90 days after a Covid infection. It’s a bit technical but I think the lateral flow tests work by reacting to a part of the viruses DNA and dead virus particles can hang around for quite a long time.

[Dotty58 in reply to Lolabridge]

Thank you for your reply. I have done daily LFT over the past 10 days (all positive) and been for 3 PCRs (all negative).

[Boxerlady]

I think that Lolabridge is right. I'm on Hydroxychloroquine and Sulfasalazine and have had no issues with Covid tests. I take regular lateral flows and did a PCR test last week (pinged as I had contact with someone who tested positive) and all have been negative. From what I've heard/read, lateral flow tests are unlikely to return false positive results although they do sometimes return false negative.

[Pinkypie2018]

I don't think your medication would affect the results. When I had covid my lateral flow and pcr test both came back positive. Like lolabridge has said there has been problems with labs giving out negative results when people were actually positive. Which can be a problem as most employers go by the results of the pcr test.

[ks1966]

Very strange. I know pcr tests are more accurate. Either way the virus is out of your system by now (if you had Covid)and as a result out of harms way.

[Moomin8]

covid.joinzoe.com/post/new-...

I report to the Zoe App everyday. It show what the actual symptoms are for Covid, now, and constantly updates. The Government's reported Covid symptoms are about 18 months out of date!

play.google.com/store/apps/...

api.covidradar.org/launch/

[Dotty58 in reply to Moomin8]

Thank you for this, I was not aware of the ZOE app but have now signed up. It's a very useful place for information.

[Moomin8 in reply to Dotty58]

👍It's brilliant and very informative! Also, you can get PCR tests referrals through the app, if needed.

[Elmo333]

Dotty, I’ve had exactly the same thing! I’ve had 10 positive lateral tests in a row but 2 negative PCRs. I’ve been told different things by doctors. Some have said to only take notice of PCRs but others have said that lateral flow tests rarely give false positives so getting 10 would be like winning the lottery! I am almost asymptotic but isolating for 10 days. The Rheumy nurse said nothing to do with ra meds x

[Dotty58 in reply to Elmo333]

Thank you Elmo, this situation has driven me crazy. None of it makes any sense whatever way I try to interpret it. I chose to self isolate "in case" I had Covid as I was experiencing some odd mild symptoms, (even though the 2 x PCRs were negative) but at the end of my 10 days the LFT indicated a clear positive (again) but the follow up PCR was negative (again).

I wish I had been able to speak to my Rheumy team but despite leaving messages during my 10 day isolation, no response as yet.

I now firmly believe my mild symptoms were as a result of the introduction of a new medication to those I was already taking, these have disappeared now so I'm certain I'm symptom free - but a LFT this morning is again positive !!!! I've had 3 negative PCR results in the space of 10 days, so feel another one is a bit pointless. It's very confusing.

[Boxerlady in reply to Dotty58]

If you have had Covid you'll continue to have positive lateral flow tests which is why they tell you not to keep taking them for 90 days after infection.

[Dotty58 in reply to Boxerlady]

Thank you, I did know this and I completely understand but I have no idea if I have really had COVID or not as the 3 PCRs(all within the last 10 days) have all returned as negative.

[Boxerlady in reply to Dotty58]

Yes, it must be frustrating - as is so much about this stupid virus 😡

[AnnieJ123]

Thank you for your post. You are not alone as the same has happened to me and others with RA. I saw a post here written by another member with 58 replies written 4months ago saying the same. This is why I joined health unlocked.

I have tried a total of five lateral flow tests , all showed positive. CPR negative.

Looking at research papers and the posts on health unlocked I saw that this was a common problem with lateral flow tests and RA patients possibly due to cross-reactivity of antibodies causing false positive results, but there was little statistics available, and the only explanation I could find, but there might be others too. The posts suggested sending an email to: [e-mail] .

I informed them yesterday and my GP and Rheumatologist.

The more we report it the better so that data can be gathered. It might give information about RA and/or the Covid virus so I feel we have a responsibility to share information.

Hopefully if enough of us report it, we will get an explanation and a way forward.

[Dotty58 in reply to AnnieJ123]

Thank you, that's great information to share with me and yes I totally agree. If there is an anomaly out there it does need some attention/ data/research . I will email today. Really, when it comes down to it all I want to know is if I have had COVID or not - seems I don't qualify for the AntiGen tests (to see if you have anti-bodies for COVID) because my PCRs have all been negative. Very frustrating.

[AnnieJ123 in reply to Dotty58]

Thanks Dotty. They say that the CPR test is far more accurate and eliminates the lateral flow test so it more probable you haven't. I have had RA for about 40 years and just had my booster- so 3 vaccines. I felt well when I went for the booster but then had a few common vaccine side effects so I did the lateral flow test out of curiosity, not because I had covid symptoms but to familiarize myself with the test. I was shocked with the results, then thought I could be symptom free. I was reassured by the posts here and articles I saw and the reassuring CRP results. I do understand your uncertainty. I am retired and have purposely had limited contact with others and take every precaution possible. I am confident I have not had it. I hope we get an explanation as we would be self isolating on a frequent basis and might have trouble going abroad. Try and find the previous post 'Consistent false positive lateral flow tests for Covid. Anyone else experienced this? by MelissaM1987' It was her post that helped me.

[Dotty58 in reply to AnnieJ123]

Annie, thank you. That has reassured me no end. I have now sent an email to [e-mail] and it says they will respond in 5 days.I too have been extremely careful and have limited where I go, what I do etc etc and am convinced that I have not had Covid, but there is always that niggly doubt at the back of your mind and I would be devastated if I had unknowingly passed it to someone else. I am retired too but work occasionally when needed as an Exam Invigilator at my local school. Their advice was to self isolate and not come into work as I had "symptoms" and a positive LFT, despite receiving a negative PCR. I was very disappointed but completely understood why they were saying this. Yes, if this happens because of my medication it will possibly rule me out of travelling.

I will look for Melissa's post. Thank you again, I know I'm not going crazy now

[AnnieJ123 in reply to Dotty58]

Delighted Dotty that you have also sent an e mail to BRS. I also isolated as I would also be devastated if I passed it on to anyone else even though I was confident not to have it. This is why I would like some action on this anomaly as it will have implications for work, social events and travel for many. We would have to be exempt from lateral flow tests but have evidence from a CPR. Melissa's post showed people were on a range of different meds so I am not sure if it is due to the medication. Sulfasalazine which I also take is acidic and I know that some children ( they learn all the tricks) get false positive results by adding orange juice. They think RA is caused by a virus so we as RA patients might have a virus or bacteria in our system detected by the test that interferes with the results causing a false positive. I could be completely wrong here and would like an explanation from an expert, thus contacting BRS. Schools will be extra vigilant over having regular lateral flow tests, I think you might need a letter from your doctor to support you over this as it could affect your employment opportunities. This is a baffling phenomena for research scientists too !!! Hopefully we will get answers and a solution.

[Elmo333]

Where do you live Dotty? I’m in East Kent, I have wondered if it could be a lab issue. What I have learnt in this situation is that the whole thing is very poorly understood even now. The average GPs are just giving their opinions, not based on facts. Very frustrating!

[Dotty58 in reply to Elmo333]

Elmo - I live in East Kent too (Sittingbourne) - my 3 PCR tests were all done at different testing stations (Sheppey, Maidstone, Sittingbourne) - if it is a lab issue then it really does need investigating. When I send my email, I will indicate where I live. Maybe, just maybe it will highlight an issue Thank you

[Elmo333]

Good idea, what email address are you informing, I will do the same x

[Dotty58 in reply to Elmo333]

Elmo, I have just sent an email detailing my circumstances to [e-mail] .

[Elmo333]

I was instructed to use this [e-mail] There is also an online form to complete on the test and trace site. I will post link in a mo

[Elmo333]

Online formHttp://enquiries.test-and-trace.nhs.uk/s/

[Dotty58 in reply to Elmo333]

Thank you, I will do that one too.