Jump to content

False positives


sotrue

Recommended Posts

Are 4th generation tests creating a lot of false positives? Does a true positive still mean there could be HIV in one’s system? Ok I may be driving myself crazy here. The scenario:

I’ve had two reactive 4th generation tests, one in Feb of this year and one in August of this year. The first time I saw this my heart sank but then I got mad. I knew I hadn’t had sex with anybody who was HIV positive. In both the Feb and Aug tests the lab followed up with the differentiation tests — no HIV detected. Then the NAT test - no virus detected and both were considered “false positives.” 
 

Being the paranoid person I am I’ve probably taken 6-7 tests over as many months including a 4th generation from another lab that was simply “negative” as well as oral home tests - all negative.

I could blame one reactive test on a lab screwup, but 2 reactives in the space of 6 months?   I’ve freaked myself out researching what could cause the reactive results -lupus, lymphoma, RA, even Covid…at least my blood work doesn’t show any signs of cancer. My partner remains negative but I haven’t mentioned how I’m worried that all the negative tests are wrong (even the follow up ones at the lab that flagged the initial reactives but deemed them false positives) and somewhere HIV is in my body. Fantasy is one thing…reality is another.

In terms of sex I have been fucking one person who repeatedly tests negative. Haven’t had sex with a guy in almost three years and tested negative shortly after that. Barebacking just remains what I read on this site.

Last week took a test again — negative again. 
 

Is there even a remote chance I could be infected? 
 

Link to comment
Share on other sites

In 2018 I tested positive on July 24 with a 4th generation antibody test. Confirmation test was Negative, and the second confirmation was also negative.

Tested positive ultimately in September when they retested the sample done at the same time as the other two. (Was in a Research study) Ask your doctor for one of these. Indeed, they are also called HIV 1 RNA Test. These are accurate with less than a week of time after exposure.

Edited by rPup
Clarity
  • Like 1
  • Upvote 1
Link to comment
Share on other sites

Did you have any vaccinations prior to testing? There are cases in medical literature (NEJM among others) of Flu and other immunizations causing false positive test results, caveat being that the immunization was recent with respect to your test. It is also theorized that recent infection with other viruses (Epstein Bar for example) may trigger a false positive. 
 

It’s important to remember that these fourth generation antibody/antigen tests are ordered with “reflex.” This means that if a positive result is given initially, the lab specimen goes for additional and more specific testing. If you have a positive test result, this portion should either confirm or refute that result. 

  • Like 1
Link to comment
Share on other sites

It's probably helpful to describe what a 4th Generation HIV test is, and how it works, and then look at why you might have a false positive.

Traditional HIV tests rely on testing for HIV antibodies - the cells produced by a body in response to an HIV infection. So strictly speaking, what these traditional tests are looking at is not whether you currently have an HIV infection, but whether your body is producing those antibodies. And while it's generally true that your body won't be producing HIV antibodies unless there's an infection present, that's not necessarily the case.

4th Generation tests look for both HIV antibodies and something called P24 antigens - a part of the virus that usually appears within a couple of weeks of infection, usually earlier than HIV antibodies, and so these tests can detect HIV earlier.

But - they aren't foolproof, and there's documented evidence of several things that can cause false positive results. One of these is SARS-OoV-2 antibodies, which can be generated by having had a COVID-19 vaccination or by having had COVID-19 itself. There are other issues like liver conditions (including hepatitis) and autoimmune conditions that can also cause a false positive 4G HIV test.

The important thing is that the follow-up tests revealed no infection. Those tests are much more thorough; they take longer, though, and are more costly, hence why they're only done if there's an initial reactive (positive) test result. Given that normal blood testing for HIV-positive individuals can find HIV even at the "undetectable" levels - that is, "undetectable" doesn't mean that HIV isn't present, it's just in such small numbers that it's clearly under control - the likelihood that THOSE tests were wrong is very, very low indeed.

 

  • Upvote 2
  • Thanks 1
Link to comment
Share on other sites

1 hour ago, Close2MyBro said:

You should probably ask your doctor to test for a viral load. If you're not on prep, or have stopped prep for at least a week, they should find a viral load present if you're positive. If they can't detect a viral load, you're likely negative.

A viral load test is part of the confirming test that the OP already mentioned - that's part of the retesting procedure after a positive/reactive result on the original test. That's how they rule out false positives.

Link to comment
Share on other sites

Thanks all. I figured this discussion might be useful for people who’ve encountered this rare situation. 
 

FYI the testing sequence for the last test was as follows:

Ab/p24 ag with reflex: preliminary reactive

HIV1/2 differentiation: Both non reactive for 1&2, determination negative

HIV 1/2 Qualitative RNA: both negative, determination HIV negative possible biological false positive No antibodies confirmed and no HIV1/2 RNA detected.

At the same time I did the August test I submitted a blood sample test to another lab that in one shot reported a 4th generation *negative* result. So these contradictory test results made no sense. All the while for 6 months after the first false positive I took several oral HIV tests — all negative. Never been on prep and I was not playing with anybody except one person. So this is isn’t case of me partying and taking loads and wondering about results. I haven’t had gay sex in 3 years and during that time I’ve had negative tests.

 

I have had flu vaccines and all the CoVID boosters, but that was months before the first false positive. I have been diagnosed with fatty liver disease, but supposedly liver function is “normal.”

There’s a lot of emotion and thoughts around this, thus the paranoid questions. Thanks again!

Link to comment
Share on other sites

11 minutes ago, BootmanLA said:

A viral load test is part of the confirming test that the OP already mentioned - that's part of the retesting procedure after a positive/reactive result on the original test. That's how they rule out false positives.

His original post made no mention of any use of PREP, which can affect the NAT test, there's a 10% margin of error on false negatives when testing for NAT while on PREP. [think before following links] https://pubmed.ncbi.nlm.nih.gov/32965051/

Link to comment
Share on other sites

1 minute ago, Close2MyBro said:

His original post made no mention of any use of PREP, which can affect the NAT test, there's a 10% margin of error on false negatives when testing for NAT while on PREP. [think before following links] [think before following links] https://pubmed.ncbi.nlm.nih.gov/32965051/

But that refers to false NEGATIVE testing. The OP was getting false POSITIVE readings, and the follow-up to those DOES involve testing for an actual viral load, period.

In other words, you're proposing a potential solution to a problem the OP doesn't have, a solution that nonetheless he would already have experienced during the care he reported.

Link to comment
Share on other sites

Thanks Bootman — correct never had any PREP issues as I never needed it because I didn’t have a lot of sex. I’d like to say I’ve spent the last few years bottoming but that was not the case. Lived a straight het life.

Beginning to think it’s the particular lab’s practices that caused the issue. 

I hinted at my dilemma in an earlier post. My first and only BB experience was 3 years ago. It was a low point in my life and COVID really took a psychological toll on me. Further the straight relationship I had sucked and I really didn’t care anymore and I wanted to see what all the fuss was about. So I took a load, it felt good, but immediately regretted it even though the guy I had sex with swore he was neg.  Waited 45 days, no sex with my partner, then tested…negative. 
 

Since that decision the relationship has gotten so much better, and I see a future with someone who accepts that I’m bi (I know, not congruent with most of what this site is about). We talk about finding a boyfriend for me so I can live out the fantasies in a safer manner. And sure, reading stories about getting pozzed is a fetish, but one in real life I really don’t want to pursue — no offense to those who do.

Now, these false positives are scaring me, making me feel that I screwed up. I certainly don’t want to infect anyone else (I haven’t). 

Link to comment
Share on other sites

  • Moderators
3 hours ago, sotrue said:

I haven’t had gay sex in 3 years and during that time I’ve had negative tests...

My first and only BB experience was 3 years ago...

Now, these false positives are scaring me, making me feel that I screwed up. I certainly don’t want to infect anyone else (I haven’t). 

Given that it sounds like you have been in a monogamous (heterosexual, though it doesn't particularly matter) relationship for the last 3 years, of course you couldn't be poz (unless your partner gave it to you). In fact, given the probabilities involved, I'm rather surprised that you were even bothering to test.

So my suggestion would be that you think through the issue and maybe look at the real math involved. And ask yourself why you were (illogically) worried enough to test, and scared by the false positives (when it was fairly clear that that was the only realistic likelihood). If there's some unresolved psychological issue or fear going on, take care of that so that it doesn't make your life miserable. Because having a healthy respect for the risks of sexual activity is prudent and sensible, but having unreasonable and unrealistic fear of them is a recipe for unneeded unhappiness.

I understand the knee-jerk reaction of fear of a lethal disease (I've had it myself), but the scientific reality of HIV in the 2020's is a very long way from what it was in the 1980's.

 

  • Upvote 3
Link to comment
Share on other sites

3 hours ago, viking8x6 said:

Given that it sounds like you have been in a monogamous (heterosexual, though it doesn't particularly matter) relationship for the last 3 years, of course you couldn't be poz (unless your partner gave it to you). In fact, given the probabilities involved, I'm rather surprised that you were even bothering to test.

So my suggestion would be that you think through the issue and maybe look at the real math involved. And ask yourself why you were (illogically) worried enough to test, and scared by the false positives (when it was fairly clear that that was the only realistic likelihood). If there's some unresolved psychological issue or fear going on, take care of that so that it doesn't make your life miserable. Because having a healthy respect for the risks of sexual activity is prudent and sensible, but having unreasonable and unrealistic fear of them is a recipe for unneeded unhappiness.

I understand the knee-jerk reaction of fear of a lethal disease (I've had it myself), but the scientific reality of HIV in the 2020's is a very long way from what it was in the 1980's.

 

Viking8x6 thanks. Funny enough the testing was linked to finding a potential playmate for me, and the gentleman and I both tested. With the false positives I had to find a quick excuse to hold off on pursuing this. I was happy to find I was free of everything else including HSV 2. So there was disappointment but also panic at the possibility that somehow I was harboring HIV and didn’t know it. Again I told my het partner, she’s tested twice and she’s been negative with no false positive results.

Maybe it was growing up in the 1980s, or simply not wanting to cause harm or guilt over going BB the way I did ( I envisioned my first time being with candles and music, not “Fuck it, let’s do it and roll the dice.”) I was also concerned about tangential stuff. I used to give blood frequently due to my much-demanded blood type, and I thought about doing so again, but I didn’t want to be flagged in some Red Cross or county database. 

I don’t want to come off as whining and there are people who have worse concerns and struggles, especially health-wise. For people who do struggle with this type of weird situation I hope this thread can provide some background. 

I’m pursuing different possibilities for why the false positives occurred and will try another 4th gen test again at another lab to see if this occurs again. If it does, I’ll be in the weird limbo -am I or ain’t I?

Link to comment
Share on other sites

7 hours ago, sotrue said:

I’m pursuing different possibilities for why the false positives occurred and will try another 4th gen test again at another lab to see if this occurs again. If it does, I’ll be in the weird limbo -am I or ain’t I?

As I understand it, the primary benefit of 4th Gen tests is that by detecting antigens in addition to antibodies, they can "spot" HIV earlier than other tests.

But that antigen testing is also, as I understand it, the reason for many of the false positives (because other things are known to give a reactive result besides the p24 antigens).

For whatever reason, you've had two false positive results from this kind of test. My guess - purely conjecture - is that you have something else in your system that sets them off; as noted, that could be as simple as having had a COVID vaccination and/or a COVID infection in the past. If so - and getting the same false positive result from another source would tend to suggest that's the case - then you might consider whether, given your circumstances, taking a less-sensitive test might serve you better. Especially if you're have a limited-enough "outside the relationship" sex life that your risks aren't that high, generally speaking.

Otherwise, my concern is that every time you take a 4G test and it comes back reactive, you'll be in a mild panic mode, which isn't good for your mental health. 

  • Upvote 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use, Privacy Policy, and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.