False Positive - New Question

[surferpaul]

Hi there, I have a couple of questions relating to the topic of false positives in HSV 2 testing. Here goes.

I just received a positive result for both HSV 1 and 2, as well as a CMV IgG of 17.4.

I do suffer from cold sores, so obviously  I have HSV 1, however, I am questioning whether the HSV 2 result is accurate.

I am in the process of having a Western Blot test organized, but in the meantime, I wanted to ask if such a CMV result, coupled with a known positive HSV 1 result, perhaps effect the results for the HSV 2 test? I was not given any levels, just the result "positive" on the result form.

I also wanted to add that when I was a child I suffered from at least 2, if not 3 bouts of Chicken Pox (believe it or not, but that is what the doctors said at the time). Since the virus that causes Chicken Pox is part of the herpes family, I am wondering if that could also be a factor in the test results?

Regarding the Western Blot test, can it be used to diagnose anything more specific regarding the CMV test, or even HPV in men? Is there any test for HPV in men?

If the Western Blot test is not appropriate for either one, are there alternative tests that can be performed to help diagnose any other ongoing infection that might be related to either of those virii?

Regarding HSV, given my history, can I be confident in the results of this test? Will I be able to trust the results of the Western Blot test?

Thanks for the reponse, just trying to figure out if my life is about to be turned on it's head :)

Paul

[H. Hunter Handsfield, M.D.]

Terri Warren (Westover Heights Clinic) and I are close friends.  I endorse her expertise and her excellent handbook without reservation.  But I'm pretty sure the statement you quote was intended as a possible but not proved explanation.

But to check myself, in response to moet's question I emailed Rhoda Morrow, the world's premier HSV serology expert.  HHH:  "It is often said that the non-type specific HSV tests, and in particular the IgM tests, often are false positive because of cross reactivity with antibody to other herpes group viruses, eg VZV, CMV, etc. Is that known to be the explanation, or is it speculative?"  Dr. Morrow:  "Essentially no published data on this point.  There are conserved regions between VZV and HSV in some of the major proteins but these don't appear to contain major epitopes.  CMV and other human herpesviruses don't have much, if any, sequence overlap with HSV."

She added some technical information about why false positive IgM tests are common for all infections, not just HSV.  The bottom line, and the translation of the scientific terminology, is that prior infection with other herpes group viruses (mono, chickenpox, etc) is not the reason for false postitive HSV IgM tests.

HHH, MD

[t1234]

In that case, I think you're definitely doing the right thing by having a Western Blot ran.  Let us know what the results are.

Best Wishes

[surferpaul]

I called the place that did my test, and I was told it was a screen by a test made by a company called Wampole. The test did not give any numbers, just a "positive" for HSV, both 1 and 2.

I have ordered a WB kit and will send it in for a test as soon as it arrives. I guess that is the best way to go, and get through all the ambiguity.

Dr H, I am not sure I follow what you are saying about the other herpes virii effecting the test. Are you saying it could be, just not really studied and understood at this point?

Thanks again for the responses.

Paul

[H. Hunter Handsfield, M.D.]

To my knowledge the reasons for false positive IgM HSV antibody tests (and other older, nonspecific IgG tests) is not known.  It wouldn't surprise me if cross reaction with other herpes group viruses is part of the reason, but I believe that is speculation, not proven fact.  I am happy to stand corrected if there is definitive evidence, but those viruses definitely do not affect type-specific IgG testing or Western blot.

HHH, MD

[moet]

Dr. H: I thought the IgM result is inconclusive because it does take into consideration past viruses like chicken pox etc. Just mentioning it because you said chicken does not effect an HSV results or something like that ;)

[moet]

Dr. H: In this document http://www.westoverheights.com/herpes_handbook.pdf
it does specify that IgM tests should be avoided since they do pick up chicken pox and mono for example. Actually, a great read for those that haven't seen it ;)

[t1234]

What was the HSV2 IGG number?

[H. Hunter Handsfield, M.D.]

To my knowledge, blood tests for HSV and cytomegalovirus (CMV) do not cross react in any way; that is, your positive CMV test has no bearing on interpreting your HSV test results.  The same is true for varicella zoster virus (VZV, also called herpes zoster); your chicken pox history will not any effect on HSV test results, whether by standard ELISA testing (HerpeSelect and others) or by Western blot.

Bottom line:  If you have a definitely positive test for HSV-2 and HSV-1, you should assume you are infected.  Your CMV test result and chickenpox history make no difference.  And if you go ahead with Western blot testing, you certainly can trust tha result.

There is no test for HPV in men, and HPV does not affect HSV testing.

Most people with HSV-2 infection do not have their lives turned on their heads.  Some adjustment perhaps, but generally not as big a deal as your question seems to imply.  If not yet done, I strongly recommend you look at the herpes information on the American Social Health Association website (www.ashastd.org) and then consider phoning their herpes information line for personalized, expert information.

Good luck-- HHH, MD