Potential HSV-2 False Positive from IGG Test

[Countingcrow]

I am asymptomatic and took the Igg test for HSV-1 and HSV-2 through LabCorp (Stdcheck.com) earlier this week and received index values of 1.56 and 10.50 for HSV-1 and HSV-2, respectively. In October 2022 I received test results from Quest of 1.40 and <0.90 for HSV-1 and HSV-2, respectively. The HSV-1 diagnosis is not surprising since I’ve seen a cold sore near my lip once a year or so for 20 years or more, but the HSV-2 diagnosis is surprising (and anxiety inducing) since I am asymptomatic and I haven’t had unprotected sexual activity with anyone I’ve known to have HSV. Earlier this week my ENT doctor also diagnosed me with mononucleosis based on a 3-day fever of 104 and an extremely sore and swollen throat below my tonsils (no testing performed to confirm). I’ve been taking antibiotics, Prednisone, vitamin C and D, ibuprofen, Tylenol, and pseudoephedrine prior to the blood draw for HSV. Is it possible that these medications or the sickness could have contributed to a false positive HSV-2 result? I’ve scheduled an appointment for next Friday with you (only day shown available on your calendar), but I was hoping for some feedback prior to help ease this crippling anxiety. I’ve also ordered the western blot test from UW. Thank you!

[Terri Warren]

So are you saying that the HSV 2 was 10.50? do I have that mixed up?
Did you have sex with very many people between this October result and when you did the most recent test?

Terri

[Countingcrow]

Correct, HSV-2 was 10.50. I have had unprotected sex with two women since then.

[Terri Warren]

Did you have unprotected sex with many different partners between October and this test? I wasn’t asking about partners since the test, but really, having unprotected sex with someone after a high HSV 2 index value positive seems quite reckless to me.
If you doubt this lab test, get a western blot but please – use condoms for sure!
Terri

[Countingcrow]

My response wasn’t clear, I have not had unprotected sex since the high HSV-2 result that I received this week, only between that result and the previous one in October 2022 that showed no HSV-2.

Is it possible that the viral illness I experienced (presumably Mono) and/or the medications I mentioned could trigger an erroneously high HSV-2 IGG value? The partners I’ve been with since October were tested and negative for HSV-2. I am planning to do the Western Blot, but would like a glimmer of hope before I receive the results if possible.

[Terri Warren]

Well, how about the three months before you did the negative test? It can take 12 weeks to become positive on the IgG test but most people seroconvert by 8-10 weeks.

Terri

• This reply was modified 3 weeks, 2 days ago by Terri Warren.

[Countingcrow]

No unprotected sex for 3 months prior to the October 2022 test, only protected sex with latex condoms during that time period.

[Countingcrow]

I found a 1987 publication in the ASM Journal of Virology (https://journals.asm.org/doi/pdf/10.1128/jvi.61.4.1125-1135.1987?download=true) by Balachandran, et al, that reports gG antigenic cross reactivity between HSV-2, ebstein-Barr virus (EBV), and cytomegalovirus (CMV). Since EBV and CMV can cause Mono, which I was diagnosed with last week (3 days after my blood draw for HSV testing), is it realistic to believe that the IgG value of 10.50 for HSV-2 was actually the antibody response to EBV or CMV given their antigenic cross-reactivity? Additionally, is it reasonable to expect a similar potential false positive from the Western Blot due to this antigenic cross reactivity?

Sorry for the very in the weeds question, but any insight you have into this topic could help relieve the crippling anxiety this diagnosis has caused me.

Thank you!

[Terri Warren]

I believe that we’ve spoken on the phone and you’ve ordered a western blot for clarification

Terri

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