interpreting herpes IgG

[kyje]

I recently went in for an annual exam and requested blood work to test for STD's.  I told my NP not to worry about testing for Herpes 1, since I have had fever blisters (oral) in the past.  I did request a test for Herpes 2, and am growing increasingly confused over the results.  The results are as follows:

Herpes II, IgG "out of range" are 2.7 H
Reference Range is <0.91
Negative Specimens.... <0.91
Positive Speciments....>1.10
Equivocal Specimens....0.91-1.09

What does this mean exactly?  My Nurse Practioner told me that I tested positive for genital herpes.  However, after reviewing this site, it seems like this could be a false postitive since 1)my numbers are relatively low and 2) because I have Type I (and results can be "cross reactive"??!?.  (As an aside, I have never noticed Herpes in the genital region, although I realize many people do not experience noticable outbreaks.)  If I am interpreting previous posts on this site correctly, it seems I have roughly a 50/50 chance of the test being a false positive.

Should I follow up with an additional test?  I am looking for any insight into how to interpret the results, and a suggested course of action would be much appreciated!

[H. Hunter Handsfield, M.D.]

I'm confused by the words 'out of range', but presumably that particular laboratory uses that phrase to mean the result is abnormal.  A result <0.91 means no HSV-2 antibody is present, >1.09 means antibody is present, and 0.91 - 1.09 is equivocal, i.e. it is uncertain.

In other words, your result is positive.  However, you are right that some results that are technically positive, but under 3.5, are falsely positive.  That is more likely if someone also is positive for HSV-1 antibody, so if you indeed have been infected with HSV-1, your 50:50 estimate is about right.  You can sort this out by repeat testing with a different HSV blood test.  For example, your provider could do the BiokitUSA test; if positive, you definitely have HSV-2, and if negative you probably don't.  Or ask for a Western blot test, which can be done by the University of Washington clinical laboratory in Seattle.  That's the gold standard to know for sure.

Best wishes--  HHH, MD

[Jeremy44]

There could also be a chance that your positive HSV-2 test is indicative of your oral herpes and not genital herpes. I'd take another blood test that will test both of them at the same time, unless of course you've already tested positive for HSV-1 before.

[H. Hunter Handsfield, M.D.]

Theoretically possible, but unlikely.  Recurrent oral herpes is almost never due to HSV-2.  But it is true that an HSV-1 blood test might help sort things out.

[kyje]

It seems like I read on one of the posts that if there is a fairly significant discrepency between the IgG for herpes 1 (for example, a 6 IgG) while for herpes 2 there is only a 3 IgG, then that increases the likelihood of a false positive read for Herpes 2.  In short, if the IgG's are similar, (say both around a 6 IgG), then the results are more likely to be accurate.  Am I understanding this correctly??!!?  
  
Time for a follow-up regardless!  Thanks!

[monkeyflower]

It's not that the two values should be similar, but that having HSV1 can skew the results for HSV2. Unless the HSV2 value is above something like 3 or 3.5 (I can't remember exactly), it may be a false positive.

[H. Hunter Handsfield, M.D.]

I don't know of any data on the "similarity" of the two values.  Don't try to over-interpret your results.  You have an even chance of having HSV-2 or not having it; there is nothing more that can be said from your results.  Retesting, as I suggested above, is the only way to sort it out.

The other way around, monkeyflower.  If HSV-2 result is UNDER 3.5, it can be false positive if someone also has HSV-1.  (I think you know this--probably just a typo.  But I didn't want others to be misled.)

[monkeyflower]

Yep, that's what I was trying to say, in my inarticulate way :-) Thanks for clearing it up!

[Confused29]

This is the first time that I have been tested and here are the results:

Herpes I IgG: 1.7
Herpes II IgG: 0.00

Herpes IgM: .65

What does the results actually means? Do it shows if it was a recent infection or past infection?

It has been a few days and sincerely very depressed and my life is changing very fast. Another test is scheduled in a month.

I have read a lot of stuff in these days about this but still feel very confused.

I will greatly appreciate all the comments to help me understand them.

[concerned]

I am utteryly confused. I've just had a string of blood tests done.HIV, HSV, Syphillis, etc... They all came back negative, but the HSV2 came back w/a reading of 1.67. I have never had an outbreak, symptoms, etc....One Dr. mentioned that I may have been exposed to the antiagents because I had the chicken pox when I was a child. I am confused, scared, and worried. Does this mean I'm a carrier and can spread this infection. Please help. Here are a copy of my test results:

Component Value Flag Low High Unit
HSV 2 IGG, EIA 1.67 H <0.90   index

[santiagochilidog]

Could you please help me to understand these results, Doctor?

HSV Type II - Specific Ab, IgG      6.5 High

Negative <0.9
Equivocal 0.9 - 1.0
Positive > or =1.1

The result reads that 'equivocal may suggest early infection'.  However, I'm being told that when the reading is this high (6.5), that's an indication of recent infection (which they're definining to be <4 months).  They say that over time the reading on igG would fall to <3.5, and the higher the reading, the more recent the initial exposure.  Do you agree that a result of 6.5 indicates a recent initial infection?   And if so and with a reading of 6.5, how recent would you estimate the first infection to have occurred?  Mainly I'm trying to understand what a 'high' reading of 6.5 can mean, especially in terms of timeframes from infection.  

Thanks so much.

[islandgirl50]

I would also like to know more about the numbers that are revealed in the test.  Mine was a 9.7 (high) and I understand that this shows a highly significant number of antibodies.  Does this mean I have been infected for a while?  This is important to me. I know that I have had only one partner for the past 20 years and would like to know if I have unknowingly been living with this disease. I read in the archives that the numbers mean nothing other than positive or negative.  My partner's number came out 5 and since mine is higher, he believes I am the one who transmitted the disease to him.  Is he right about this?

[sadeye]

I would love to know the answer as well. I just found out that my IgG came back as 8.8 and I have been with the same partner for 18 years. My provider tells me that my IgM shows I have no recent infection and that I probably got infected years and years ago. I never have had a symptom in my life! I just can't believe that this test result could be accurate. Thanks for the information.

[cat542]

A related discussion, confused was started.