February 26, 2019 at 7:40 pm #31151
I understand that the IgG blood serum test looks for antibodies to HSV. I also know that HSV antibodies take a little while (~14 weeks) to build up after you contract the HSV virus. Once you build up enough antibodies in your bloodstream, the IgG results will tell you that you’ve passed the threshold that is considered a “positive” result.
I know that there are different types of antibodies. My layman’s understanding of HSV antibodies is that once they are produced, they last several years or a lifetime. Is that correct?
The reason that I ask is because I was diagnosed as HSV2+ through a blood spot test (not a blood serum test). I was told that it was a clear positive, so I began antiviral medication. It made sense – I am married so my exposure date could be years ago. Definitely more than 14 weeks.
I took 500mg of valacyclovir for nine days before I was tested again with a “standard” IgG blood serum test at Quest Diagnostics. The index result was “less than 0.9” and “negative.”
I then read on this forum that taking antiviral medication essentially makes the virus “invisible” to the test because it cannot detect antibodies.
Does taking daily 500mg of antivirals actually lower the amount of antibodies in your bloodstream? Are antibodies produced daily and go away daily, only to be supplanted by antiviral medication?
I actually have an appointment to get the Western Blot tomorrow but have learned that it might not be accurate if I am on antiviral medication.
Please help me understand this so that I can figure out what to do next. It sounds like I might need to stop taking antivirals for 14 weeks and then get the Western Blot.
Thanks in advance.
March 1, 2019 at 11:35 am #31292
Your understanding isn’t correct. If antiviral medicine is taken immediately after first infection, it can make the antibody development greatly delayed, correct, but that is not true if the infection is old, which it sounds like yours would be, correct?
The information about taking the antiviral medicine is NOT correct as it relates to someone with long ago infection.
Was your blood spot test through MyLabBox or what service did you use?
You should go for the blot now.
March 1, 2019 at 1:31 pm #31306
Thanks so much for the reply. This makes much much more sense.
Yes, mine would be an established infection. At the VERY least 12 weeks, but probably years (I know that might sound strange but it is the case).
My blood spot test was through MyLAB Box. It came back as positive. The index value was 1.207 although that seems to be irrelevant because they use a different scale that is much lower (due to the blood being concentrated I think?).
I took valacyclovir for 8 days before getting my blood drawn at Quest for a “regular” IgG blood serum test. It came back as negative.
I continue to take daily valacyclovir. Two days ago I had my blood drawn for the Western Blot (14 days on valacyclovir at that point). It was mailed to your lab yesterday. I hope that it arrives today.
As it stands, I have one positive blood spot IgG test and one negative IgG serum test. No symptoms.
Thanks again for the answer. I had been told that antivirals sometimes Interfere with blood tests and I misunderstood the reason why.
March 1, 2019 at 8:35 pm #31332
yes, well, I’m not convinced AT ALL about that with MyLabBox. I have had two people who told me they tested positive on the MyLabBox at low numbers who did NOT confirm on the blot, and that’s just so far!
Given the confusion, you may wish to do the western blot and if you do it, PLEASE let me know your results. I’m getting ready to talk with the MyLabBox people about this.
March 6, 2019 at 9:48 pm #31522
The Western Blot came back negative for HSV2 (and HSV1). As did two prior IgG tests from Quest. So it is only the MyLAB Box test that returned the false positive.
I know you hear this all the time, but thank you so much for everything that you do. Without you and this organization I would have been lost during this process.
March 14, 2019 at 7:56 am #31822
I am so sorry that this happened to you. I have asked to meet with the head of MyLabBox to discuss their testing procedures. You are not the first person to have this happen and it concerns me greatly.
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