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Positive elisa, now what?

Hello Dr.

My last exposure was more than a year ago and it was unprotected sex. I had an ELISA test performed through quest lab and it came back "repeatedly reactive". The lab then proceeded with a Western blot, which was Negative. Now, they have sent my blood off to another lab so that it can get tested with what is called an immunoblot. My doctor explained that the western blot looks just for hiv 1 and that the immunoblot looks just for hiv 2. I am still awaiting the result of the immunoblot, which wont be in until the end of next week. Here are my specific questions..

1) If i am infected with hiv 2, would the western blot have been intermediate? More specifically, does the WB look for proteins that both hiv 1 and 2 have?
2) Are there different Western blot? Like, do some WB look for both hiv 1 and 2 and others look just for hiv 1?
3) Is the Doctor correct about the purpose of western blot and immunoblot? Why would the lab do such a test if the western blot was negative?
4) I have also had 3 rapid tests done since this exposure, which were also after the window period. Two of them were unigold rapid test, but they ONLY are FDA approved for detecting hiv 1. Also I had 1 oraquick advance done. It is FDA approved for both hiv types.Should I have any bit of faith with this negative oraquick advance test (roughly 6 months post exposure).
5) Lastly, How likely is it that this immunoblot test will be positive. I am a white female who has never engaged in any sexual activities with anyone from west africa. I am not sure about my partners past, but I can say that he has had a "shady" past that I have recently been aware of.

Thank you in advance for you help and answers.
8 Responses
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300980 tn?1194929400
MEDICAL PROFESSIONAL
Gladd to hear your results. Thank you for sharing. EWH
Helpful - 0
Avatar universal
Dr Hook
Wanted to share the results of my HIV 2 immunoblot-negative!  What a relief. Thank you for the reassurance and advice. I can breathe again. I have definitely learned a valuable lesson and will not ever put myself in this position again. Thank you so much once again.
Helpful - 0
Avatar universal
Dr Hook
Wanted to share the results of my HIV 2 immunoblot-negative!  What a relief. Thank you for the reassurance and advice. I can breathe again. I have definitely learned a valuable lesson and will not ever put myself in this position again. Thank you so much once again.
Helpful - 0
300980 tn?1194929400
MEDICAL PROFESSIONAL
You are over reading this.  Different companies make different tests. The performance characteristics and their abiltiy to detect HIV-2 thus varies as well, typically in small ways.  This space is not the place to discuss the biochemical and immunological nuances of small differences in test methods and performance.  I'm not try to be harsh but I've told you, it sounds more likely than not that you have a false positive ELISA.  Rather than get caught up in highly technical, small test differences, the thing to do now is to await your more definitve tests.  I suspect that it will show that you do not have HIV-1 or HIV-2.  Please share your results when they are available.  

EWH

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Avatar universal
Dr this will be my last question.
When you say the performance of ELISAs in terms of HIV 2 varies, what do you mean exactly. That the oraquick ELISA is unable to detect it even though it is approved for both or the lab based one?
Are you saying that a positive lab based Elisa is  able to detect HIV 2 more and that the oraquick may have been a false negative. And that I may have it?
Helpful - 0
300980 tn?1194929400
MEDICAL PROFESSIONAL
No, HIV 2 is terribly uncommon.  None of my patients have HIV-2 and I have not seen a patient with this infection.

Test perfromance varies from test to test in terms of their ability to detect HIV-2. Not all ELISAs used for HIV screening detect HIV-2 although most do.  EWH
Helpful - 0
Avatar universal
Thank you for your reply.
I am SO overwhelmed. I keep hoping that if I did have HIV 2, that the oraquick advance would have picked it up. How is it possible that I had a reaction to the lab based Elisa but not the rapid ones?
Lastly, have you ever known anyone that tested pos for HIV 2? Is it more common than we think?
Helpful - 0
300980 tn?1194929400
MEDICAL PROFESSIONAL
Welcome to the Forum.  I'll try to help.  Your results indicate that you do not have HIV-1 and it is unlikely that you have HIV-2 as well.  Typically person with HIV-2 have an indeterminant western blot.  

Let's go straight to your questions:

1.)  If i am infected with hiv 2, would the western blot have been intermediate? More specifically, does the WB look for proteins that both hiv 1 and 2 have?

Yes, with HIV-2 there is typically some reaction with the proteins on the HIV-1 western blot.  The viruses are closely related.

2) Are there different Western blot? Like, do some WB look for both hiv 1 and 2 and others look just for hiv 1?
Sorry, I am not sure abou thtis. There is no reason that there coul not be a western blot for HIV-2.  

3) Is the Doctor correct about the purpose of western blot and immunoblot? Why would the lab do such a test if the western blot was negative?

No, most scientists use the terms Western Blot an immunoblot interchangeably.   The HIV-1 WB is different from the HIV-2 WB

4) I have also had 3 rapid tests done since this exposure, which were also after the window period. Two of them were unigold rapid test, but they ONLY are FDA approved for detecting hiv 1. Also I had 1 oraquick advance done. It is FDA approved for both hiv types.Should I have any bit of faith with this negative oraquick advance test (roughly 6 months post exposure).

Most HIV tests are approved only for HIV-1.  This is largely because HIV-1 is  so much more common than HIV-2 that it is difficult to find sufficient numbers of cases of HIV-2 to get FA approval.  

5) Lastly, How likely is it that this immunoblot test will be positive. I am a white female who has never engaged in any sexual activities with anyone from west africa. I am not sure about my partners past, but I can say that he has had a "shady" past that I have recently been aware of.

It is statistically quite unlikely that you have HIV.  My guess is that you are one of those unlucky persons who happens to have antibodies which cross react on the HIV test.  The good news however is that it is unlikely that you have HIV (1 or 2).  Please let us know when you get your test results.  EWH
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