- Confusing HSV Test Results -

[preciousmoi]

Hello. I'm a female that ended a relationship with a male after having unprotected sex with one another for 12 months. This was my first sexual partner. Due to my ex having ASPD, I was unaware during our relationshp that he was cheating on me, and was also unaware of how many partners he's had in the past (>40). I've been out of the relationship for 16 weeks now.

Last week I got screened for all STIs under the sun. Thus far all tests except HPV and HSV came back negative.

My physician told me that my IgG 1 and IgG 2 tests were negative, but that my IgM test was "equivocal."

Two years ago I was going to participate in a Herpes vaccination trial until my blood test came back as HSV 1 +, which excluded me from the study.

Can you please explain to me the following:

      [1] What could cause an HSV-1 test to come back positive 2 years ago and negative now?
      [2] What does an "equivocal" IgM HSV test mean?
      [3] Since I've been out of the relationship and sustaining from sex for 16 weeks now, if I were infected with HSV, would my tests have come back positive by now?
      [4] What are the next steps/recommendations for me? How much longer do I need to wait to learn if I have HSV??

I'm a little scared and am hoping you can offer some answers to remove some of my stress and anxiety. Thanks so much for your help!

[gracefromHHP]

I'm assuming you were trying to participate in the herpevac vaccine trials 2 years ago.  If so they most likely sent off a herpes WB blood test as your baseline herpes blood test to see if you were eligible to participate in the study.  The WB is a little more likely to pick up on a hsv1 infection than the other blood tests are. Since you had an igg and an igm test done - I'm guessing it's not a herpeselect you had done - even the herpeselect still misses picking up on 1 out of every 10 hsv1 infections - other tests have even higher rates of missing hsv1 infections.  I would still assume you have hsv1 based on the 1st blood test.

I would go with your hsv2 negative results from the testing you just had done.  No reason to continue testing for herpes at this point.  

you should've never had the herpes igm blood test done anyways . Totally disregard the results.  Here is a post made by Dr handsfield from the std experts forum here on medhelp that better explains why the igm test isn't worthwhile :

Forum-M.D.-HHH
09/20/2006
Help-Concerned You're right, this has all been addressed several times. However, it's in many places and might be hard to dig out. So I appreciate the opportunity to put it all in one place.

In theory, the body produces immunoglobulin M (IgM) antibodies first, to a variety of infections, and immunoglobuin G (IgG) antibodies later. Over time, IgM antibodies tend to stop being produced entirely. Therefore, a test for IgM antibody to any particular infection may be positive before a test that detects IgG antibody. And in a person infected a long time previously, IgM antibody is absent but IgG persists.

That's the theory. In general, it holds up pretty well in young children, but sometimes not so well in adults. In adults with new HSV infection, IgM antibody against the virus doesn't actually get produced all that much faster than IgG antibody. And many people with longstanding HSV-1 or HSV-2 infection continue to produce IgM, especially when they have a new symptomatic outbreak. Thus, for HSV, IgM doesn't necessarily mean a new infection; and absence of IgM doesn't necessarily mean a longstanding infection.

On top of that, there are 2 other main problems with IgM testing for HSV. First, false positive tests are common--that is, apparent IgM antibody that simply isn't present at all, despite what the test says. This is NOT generally due to cross reaction with related viruses, i.e. HSV-1, varicella (herpes) zoster, and the like. It has to do mostly with the physical chemistry of the test.

Second, there are no type-specific IgM tests on the market--nary a one. Any true-positive IgM test for HSV is detecting antibody to HSV-1, HSV-2, or both, and can never distinguish between them.

Why do labs continue to offer such a lousy test? Several reasons there too, some reasonable, some not. Some providers still request the test; they were taught the theory, they assume it applies accurate to HSV, and don't understand the limitations of the test. (The pediatricians generally are right; IgM testing for HSV in fact remains useful in diagnosing neonatal herpes in newborns. Their immature immune systems don't crank out IgG so rapidly.) Also, some labs just keep offering the test out of habit, in the belief the providers want the test; while at the same time, the docs just assume that if the lab does the test, it must be worthwhile. (That is, a communication issue.) Also, there is simple profit motive for labs: IgM testing is very cheap but gets good pay-off from insurance companies, so the profit margin is high.

Bottom lines: Sometimes a new HSV infection in an adult indeed will be positive by IgM before IgG. But this is pretty infrequent, and it outweighed by the downsides: high risk of false positive result; and even when truly positive, there is no distinction between HSV-1 and HSV-2, which is pretty important to most patients and providers.

In response to your question, I re-contacted the people I know at Quest Laboratories. As of last month, as a matter of policy, Quest no longer does IgM testing for HSV in adults unless the provider specifically requests it. (Some individual labs might not have gotten the word yet, so some IgM testing might be done for a while.) Quest will continue to to IgM testing routinely for HSV antibody requests in newborn.

And do the bottom line for your particular situation: Totally ignore your recent IgM result with an equivocal outcome. Almost certainly it is meaningless. If you remain concerned, have an IgG test (and only IgG) 3 months after your last possible exposure.

I hope this helps. I have a feeling I will be referring future questioners to this thread quite frequently.

HHH, MD

[preciousmoi]

Grace,

Thank you for your helpful comment. I have already read HHH's posted comments on IgM on MedHelp, as I've been panicking about these results and the waiting period. [My doctor told me to come back in for retesting in 3 weeks.]

You're right, 2 years ago I was going to be in the Herpevac study, and I'm glad that you cleared up how they tested for HSV-1 and HSV-2 for that study--western blot. So from the western blot, it's obvious that I do have HSV-1 even though my most recent blood test (1.5 weeks ago) came back stating that I don't have HSV-1. SO, I must assume that the blood test from the clinic last week was not accurate for HSV-1. If I cannot trust the test for HSV-1, why should I trust the test for HSV-2? Does the antibody test performed in the doctor's office for HSV have higher sensitivity for HSV-2 than for HSV-1?

I'm asking this because I am obviously worried. I want to be sure not to pass HSV-2 to anyone else that I care about if I have it... I just want to be as careful and honest as possible.

Thanks again. :)

[gracefromHHP]

The blood tests are more accurate for hsv2 than they are hsv1 though depending on which one you had done, depends on how accurate it is at picking up hsv2 too. Most of them are good at picking up herpes - just not always so good at differentiating if it's hsv1 or hsv2.

grace

[preciousmoi]

so, should i assume that i don't have hsv-2 and just stop getting this test performed?

thank you.

[gracefromHHP]

why would you assume you have hsv2 based on a + igm ?????

grace

[preciousmoi]

I didn't assume I had hsv-2 due to an IgM test...

I am paranoid about my ex's history of sleeping with many, many women (>40) without protection (condoms). SO, my main fear of HSV testing was that I could be positive for HSV-2.

As you know, it came back negative, but since HSV-1 also came back negative (and I tested + in the past with the western blot test for the herpevac trials), I don't know that I can trust my HSV-2 results either.

As for the IgM test, I have done more research, and being that I haven't been with my high risk partner (the ex) for 4 months, I know that the IgM wouldn't be positive due to anything from him at this moment. I've had one partner since (always WITH protection), and he says that he has never had HSV nor had any symptoms, but went in for testing today to verify this. Assuming he comes back negative, I'm not planning to be retested.

[gracefromHHP]

Teach me to answer posts at 2am after a day of not much sleep.  NOW I see the I can assume I DON'T have hsv2....sorry about that!!!

The igg is more accurate at picking up hsv2 than at hsv1. I wouldn't worry about possibly having it and not knowing it.



grace

[easygoes]

hi just wanted to confirm. I got a hsv2 test 9 months ago and the figure for hsv2 was 0.42 (IGG) and I got one done now (also IGG) which came back at 0.79. I had an initial bout of blisters which the doc said was herpes. Also had all the symptoms associated with an hsv infection such as swollen lymp nodes and headache etc . these symptoms came up about a week after unproteced sex. does this mean the virus is out of my body or that it just can't be deteced or that i never had it in the first place. Also got hsv1 tests which came back at 0.26( the first time) and now at 0.79. Highly confused , an answer would be much appreciated.