[Question #7658] HSV 2 - IGG Test

 
16 days ago
Hello - 

I'm a 31 male, caucasian and heterosexual. On 10/2020 I received a blood test result which showed positive HSV 2. The test was HSV 2 - IGG, type specific AB from Quest. The value was 1.68. 

Background

A. I have not noticed visually anything unusual in the genital area or any pain/irritation (i.e. no "typical" symptoms). 
B. I previously tested negative for HSV 2 - IGG, type specific AB (also by Quest) in 2019 and 2018. The values were <0.90.
C.  I have tested equivocal for the same type of test in 2017 (value was 0.92) and also equivocal in 2014 (value was around 1.0 or 1.1).
D.  I had two separate sexual partners (not sex workers), and engaged in unprotected oral sex and protected vaginal sex between the time of my last HSV-2 negative result and the positive result in 10/2020. 
E. 8 months have passed between my last sexual intercourse (vaginal or oral) and the date of the October test which showed positive HSV-2 (i.e. no sexual contact for eight months prior to the latest blood test). 
F. I do not have HSV-1 infection, based on IGG test from Quest. 

I would appreciate your help with the following questions:

1. Does the test result of 1.68 imply that I have HSV2 infection? 
2. Wouldn't HSV2 test show value that's higher than 1.68 given that eight months have past since the last potential exposure? 
3. I read that there is a chance of false positive when the Quest IGG test results are less than 3.0. What is the likelihood that my test result is in false positive category?

Also, I have not done a repeat test.

Thank you

Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
14 days ago
A. I have not noticed visually anything unusual in the genital area or any pain/irritation (i.e. no "typical" symptoms).
OK
B. I previously tested negative for HSV 2 - IGG, type-specific AB (also by Quest) in 2019 and 2018. The values were <0.90.
Have you had other sexual partners since then?

C.  I have tested equivocal for the same type of test in 2017 (value was 0.92) and also equivocal in 2014 (value was around 1.0 or 1.1).
I suspect you are prone to tripping the test artificially but with a now low positive,  it's not possible to really know with 100% certainty.  I would say there is about an 80% chance that this is a false positive, but with your previous test results in the equivocal range, it is probably even more likely than that that it is a false positive.

D.  I had two separate sexual partners (not sex workers), and engaged in unprotected oral sex and protected vaginal sex between the time of my last HSV-2 negative result and the positive result in 10/2020.
Oral sex is not a real risk for HSV 2 but condoms reduce transmission from women to men by about 65%, so not perfect.

E. 8 months have passed between my last sexual intercourse (vaginal or oral) and the date of the October test which showed positive HSV-2 (i.e. no sexual contact for eight months prior to the latest blood test).
Again, I am leaning strongly toward a false-positive result here

F. I do not have HSV-1 infection, based on IGG test from Quest.
Correct, but the IgG test for HSV 1 misses 30% of HSV 1 infections so we can't be too certain about that.

I would appreciate your help with the following questions:

1. Does the test result of 1.68 imply that I have HSV2 infection?
see above

2. Wouldn't HSV2 test show value that's higher than 1.68 given that eight months have past since the last potential exposure?
Likely, yes, but last week I had someone confirm by western blot who had a 1.1 to I'm alway skeptical

3. I read that there is a chance of false positive when the Quest IGG test results are less than 3.0. What is the likelihood that my test result is in false positive category?
See above.

Terri
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14 days ago
Thank you very much Terri. Just to follow up:

1. You asked whether I had sexual partners since 2019 when I tested negative. To confirm - I had 2 sexual partners between the negative test and the positive results. But I had no sexual activity for eight months prior to the positive test. 
2. You  are saying that by itself the value of 1.68 is 80% likely a false positive, but with a history of equivocal results followed by negative results - its even more likely that this is a false positive? (sorry this may be a repeat of what you already said). 
3. I mentioned that eight months have passed from last sexual activity and the date when I took the test which showed positive result. Based on some online literature it seems like this is a sufficient time for antibodies to be detected. I don't know anything about antibody process, but with that amount of time passed would the value be typically higher than 1.68 or is that not really relevant/or dependent on other factors?
4. Are there any known reasons why a person may artificially trip the HSV-2 IGG test? (i.e. something I can look at my blood work results and point to?)

Thank you again for taking the time to respond. Apologies if any of the questions above ended up redundant. 



Terri Warren, RN, Nurse Practitioner
Terri Warren, RN, Nurse Practitioner
13 days ago
1.  OK, thanks
2.  Yes, you read my opinion about that correctly.
3.  It is sufficient time for antibodies to be made, correct.  But some people simply have a lower index value and they are truly infected.  That's where the 80% comes from.
4.  There is nothing in blood work that you can point to that would be tripping the test, no, not at all.  Some people just have a protein in their blood that trips the test and also can show up on the blot as an indeterminate.  Both are so frustrating, but we even have ways of interpreting the indeterminates on the western blot that make it a very useful confirmatory test.

Terri
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