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1478210 tn?1303486885

What is the range for a positive HSV 1 IgG test?

I recently had an HSV 1 (Herpes Simplex 1) IgG test which came back positive at a level of 6.  The negative range is 1.09.

I also had an HSV, IgM I/II combination test which came back negative at 0.91.  The negative range is 1.09.

I had negative an HSV, IgM I/II combination test done five months ago, but I've never before had an IgG test.  I've never had an outbreak of lesions or even a cold sore of any kind, and I've always assumed I was negative for herpes.  The fact that 70-80% of the populations has this isn't much comfort for someone who thought they were clean.

What is the normal range or bell curve for a positive IgG test?  Given that a mere 1.09 numeric result is positive and 6 is so much higher, is there anything further I can decipher from a high numeric test result?  Given that the number is a reflection of the presence of antibodies detected which are responding to the viral infection, is a higher numeric result an indication that my immune system is more aggressive than that of a person who is positive at a numeric result of only 1 or 2?  Is it an indication of more recent infection?  Or is it an indication of a long-term infection?  Lastly, with such a high test result, should I even bother with a confirmatory test?
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239123 tn?1267647614
MEDICAL PROFESSIONAL
Welcome to the forum.  Sorry you had trouble with mathematical symbols.

First, all HSV IgM antibody test results are to be ignored.  No STD or herpes expert ever orders or recommends IgM testing, which is highly unreliable.  Here is a thread that discusses HSV IgM testing in more detail.  Even though 5 years old, the information remains accurate:  http://www.medhelp.org/posts/STDs/Confusiion-over-other-IgM-Herpes-posts/show/248394

My second comment is that probably most people are quite comforted to know they are not alone when they turn out to have a mostly benign medical condition that affects more than half the population.  In any case, since you haven't been having cold sores or recurrent genital blisters/sores, most likely you never will, and you're even less likely to have any sort of medically important complication.

To your main question:  No conclusion can be drawn from the numerical result (technically, it is an optical density ratio) of an HSV-1 (or HSV-2) IgG test, especially in the strongly positive range.  If you were to be tested 5 more times, the OD ratio might vary from 2.0 to 8.0; that could happen even if the same blood specimen were tested 5 times, using different batches of test reagents.  In other words, your premise is wrong:  the OD ratio value does not directly reflect the amount of antibody in the blood; it is more dependent on the chemistry of the test.  Similarly, the numerical value says nothing about duration of infection, its severity, the frequency of outbreaks, or the effectiveness of the immune system.  In a way, it is unfortunate that labs even report the numerical values of HSV test results.  A verbal report of negative, positive, or (sometimes) equivocal would be a more accurate representation of the meaning of the test.  

As for distribution of all results in HSV-1 positive persons (the shape of the "curve"), I don't really know; this has never come up before.  But for the reasons above, I don't think it matters.  I would guess it is skewed, i.e. not a symmetrical bell curve distribution.  I imagine a peak ELISA ratio around 4, with a fairly smooth rise from 1.1 to ~4, then with a long tail that could go out to 7, 8, or even 10.  However, results with high numbers are rarely reported; most labs create a cut-off, and report high results as "over 6.0", "over 7.0", etc.

Finally, you definitely do not need a confirmatory test.  You have HSV-1, just like roughly half the US population (not 70-80%, although it reaches that proportion in people over 60 years old).  You can now be on the lookout for symptoms of recurrent oral or, less likely, genital herpes -- but having not had any until now, most likely it won't happen.

I hope this helps.  Thanks for an opportunity for a blog-like response which I will keep handy to aid in replying to similar questions in the future.

Regards--  HHH, MD

Helpful - 2
239123 tn?1267647614
MEDICAL PROFESSIONAL
Most people feel no need to share HSV-1 status with sex partners, based only on blood test results, and I do not recommend it.

It is never possible to use a blood test to judge when an HSV infection was acquired, unless there is a negative result followed by a positive one -- which gives a window of opportunity.  Indeed it is probable you will never know when you were infected.

I hope you can settle into a state of comfort and acceptance with all this.  In case you care, I learned my positive HSV-1 status over 25 years ago, in my early 40s.  I have barely ever given it a thought since then.
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Avatar universal
A related discussion, herpes results was started.
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1478210 tn?1303486885
I appreciate the insight and prompt replies.  Thank you.
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1478210 tn?1303486885
Thanks Doc.

I hear what you are saying about the comfort of sharing a trait with 50% of the population, but it's still a disappointment to go your whole life thinking you are clean as a whistle and then to learn that you've either acquired-- or always had-- an STD.  It raises issues of whether or not I now need to share that with every woman before we even kiss, whether or not I feel comfortable performing oral sex on women, and it also raises concerns as to whether or not I've ever infected a woman without knowing it.

I'm additionally worried that I recently acquired HSV1 rather than I've always had it.  If I've always had it and I've never had cold sores, I have nothing to worry about.  But if I recently acquired it, I'm not looking forward to cold sores.  In my opinion, they seem more embarrassing than genital breakouts-- and more likely to cause anxiety-- because they are front-and-center on your face like a neon sign.

Thank you for the detailed information about the IgG test and numeric score.  It doesn't help me figure out when exactly I acquired the virus, but it does help correct my misunderstanding about the relevance of the number.  And at least I understand I may never know when I acquired this.
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239123 tn?1267647614
MEDICAL PROFESSIONAL
See below following the edited/corrected version.

HHH, MD
Helpful - 0
1478210 tn?1303486885
SORRY, THIS IS THE CORRECT EDIT:

I recently had an HSV 1 (Herpes Simplex 1) IgG test which came back positive at a level of 6.  The negative range is less than 0.91.  The equivocal range is 0.91-1.09.  The positive range is greater than 1.09.

I also had an HSV, IgM I/II combination test which came back negative at 0.91.  The negative range is less than 0.91.  The equivocal range is 0.91-1.09.  The positive range is greater than 1.09.

I had negative an HSV, IgM I/II combination test done five months ago, but I've never before had an IgG test.  I've never had an outbreak of lesions or even a cold sore of any kind, and I've always assumed I was negative for herpes.  The fact that 70-80% of the population has this virus isn't much comfort for someone who thought they were clean.

What is the normal range or bell curve for a positive IgG test?  Given that a mere 1.09 numeric result is positive and 6 is so much higher, is there anything further I can decipher from a high numeric test result?  Given that the number is a reflection of the presence of antibodies detected which are responding to the viral infection, is a higher numeric result an indication that my immune system is more aggressive than that of a person who is positive at a numeric result of only 1 or 2?  Is it an indication of more recent infection?  Or is it an indication of a long-term infection?  Lastly, with such a high test result, should I even bother with a confirmatory test?
Helpful - 0

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