A question about accuracy of an antibody test

ixchelkali

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That can be true with some types of infection. For instance, once you have had rubella or chickenpox, you will have the antibodies even though you no longer have an active infection. On the other hand, the varicella zoster virus that causes chickenpox remains dormant in your body and can become active again if you become immunocompromised, such as frequently happens with old age. Then it reappears as shingles.

Retroviruses, though, remain in the body and in some cases can cause immunosuppression, so what the British doctor said wouldn't apply to them.

Oops, this was supposed to be in response to biophil's post:
A doctor or two have told me doing antibody tests on post viral CFS is pointless because CFS is about what happens after the virus is cleared and a positive test result only indicates a previous infection.
 

Rivotril

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A bit off topic but just a single question from me:

testing during/shorty after taking antibiotics, will this affect the results of the XMRV test (antibody and/or culture/PCR)

To my medical knowledge (which is not very huge, to use an understatement :) ) antibiotics work out against bacterial infections and antivirals against viruses, so antibiotics have nothing to do with viruses, so in that case it wouldn't mind.
I'm just asking because I want to know it for sure because I want to get tested the next week or so and dont want to throw away money :)
 

omerbasket

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I'm not an expert, but: To my knowledge, antibiotics (and by the way, if I'm not mistaken, even antivirals which are specific for the virus) should not interfere with the results of an antinody test. I know that VIP Dx asked, at least in the past, from patients not to take antivirals before getting tested (with the methods that were available then, not with the antibody test), but I don't remember hearing from patients here that they have asked them not to take antibiotics.
Also, at least in general, antibiotics works against bacterias, as you said, and not against viruses.
However, my own opinion is that today we don't know everything about XMRV (we actually know very little) and therefore in my opinion there is a possibility for everything to interfere with the tests. I mean, who knows - perhaps bananas make something to the virus? To me it seems that the possibility of antibiotics to interfere with the test is similar to the possibility that bananas would interefere with the test - but personally, I think we cannot rule out the possibility that bananas don't interfere with the test.

In other words (and again - it comes from a person who is not an expert whatsoever - so I would like to hear from others here on that subject), it seems that the likleyhood that antibiotics would interfere with the test is very very low, and if you stop antibiotics perhaps you would like also to stop eating an drinking - because we cannot rule out that it would interfere with the test...
 

Rivotril

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thnx omerbasket for your answer, and the additional information that Vipdx doesnt mention anything about antibiotics before they run tests...
Which I expected as I said in my previous post, but as you say, we dunno much about XMRV, so we can say nothing for 100% sure
but thanks!
 

redo

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A bit off topic but just a single question from me:

testing during/shorty after taking antibiotics, will this affect the results of the XMRV test (antibody and/or culture/PCR)

To my medical knowledge (which is not very huge, to use an understatement :) ) antibiotics work out against bacterial infections and antivirals against viruses, so antibiotics have nothing to do with viruses, so in that case it wouldn't mind.
I'm just asking because I want to know it for sure because I want to get tested the next week or so and dont want to throw away money :)
Antibiotics do work against bacteria, but some have immune modulating effects, and may have some effect on viruses that way. But I don't think I'd be a waste to get tested while you're using abx.