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HIV 1/O/2 Abs Test Says Reactive. Western Blot Result Listed As Indeterminate. Due To Viral Infection?

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Posted on Thu, 18 Apr 2013
Question: If I received testing results with HIV 1/O/2 Abs-Index Value of 1.24, how concerned should I be as to the surety of being infected? Western Blot result was listed as Indeterminate. HIV 1/O/2 Abs. Qual indicated Repeatedly Reactive. I have not had a lifestyle that would be conducive to contracting HIV. Is is possible that such readings could be attributed to any other type of viral infection?
doctor
Answered by Dr. Achuo Ascensius (5 hours later)
Hello,

Thanks for the query.

HIV 1/O/2 Abs test is an Enzyme-linked immuno sorbent assay (ELISA) test that tests for the presence of HIV types 1 and 2 antibodies in the serum. A threshold value is usually set above which the result is considered positive. This threshold is what is called the index. If the index is taken at 1, all values below 1 will be negative where as values above 1 will indicate a positive results that will require further testing. However, time period after exposure for taking the test matters. Antibody ELISA for HIV won't show positive until after a few weeks.

A value of 1.24 is definitely above 1 and should indicate positive results. But then it’s just fairly above 1 and there are chances it could be a false positive. Several causes have been documented for being responsible for false positives for ELISA. Such factors include naturally occurring antibodies, coded antibodies on the ELISA plates, antibodies against flu causing viruses and other viruses etc.

Confirmation with western blot is indispensable but is also time related and an indeterminate result might indicate that the individual is in sero-conversion especially in people with high risks.

At this point, what would be best would be a repeat of the tests three months later or you do further testing with fourth generation ELISA or polymerase chain reaction (PCR) which detect the presence of HIV viral antigens.

Hope I have answered your query. If you have further queries I will be ready to help. If you do not have further queries, you could close the discussion and rate the answer.

Best regards.

Above answer was peer-reviewed by : Dr. Raju A.T
doctor
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Follow up: Dr. Achuo Ascensius (16 hours later)
Also, should note that P55 Ab did show as abnormal, but that was the only one. I am heterosexual and had not had any sexual encounters for over 5 years until about 3-4 weeks ago. This time with a female that I have known as a friend for several years.
Around the same time after that, I did develop some stomach issues that I have attributed to a virus going around. It has been more than a week though with the same issues and I'm not sure what prompted me, but just out of curiosity I started researching some on the internet regarding HIV.
Could there be any outside possibility that readings from these tests could by any chance be related to some other sort of virus in my system?
I am highly concerned about this since it has never been like me to think that I would ever be in position to be at risk for something like HIV.
I am not frequently premiscuous as mentioned above, and am certain the woman previously several years ago was not infected. I did initially discuss the issue with one recently prior to our encounter and she at least indicated that
she was certain she was not infected.
I guess one more question might also be that would it likely to be having any ill effects of being infected this quickly after potential exposure? Thank you.

Thank you for you time.
doctor
Answered by Dr. Achuo Ascensius (5 hours later)
Hello,
Thanks once more for the query.
Following my last response, there are basically two situations we should be looking at;
i). either you are in the window period which explains the indeterminate results or ii). You had a false results, which is but common with antibody ELISA tests.
Three weeks is rather too small to have effects of an infection such as opportunistic infections. However, it is possible to have symptoms similar to an acute viral infection such as muscle ache, headache, malaise etc that will be short lived at about three weeks following the infection.
In your case, you did have the viral-like symptoms at the time of your exposure, which is less likely to be related to HIV. A low risk lifestyle like yours is perfect but a single exposure could be disastrous. More so, you cannot be so sure of some other person's status unless she takes the test.
Well like I did indicate in last response, false positives have been obtained and it’s a common issue with several causes including viral infections.
What is necessary to do now as I indicated in the last response is to repeat the tests three months later or you do further testing with fourth generation ELISA or polymerase chain reaction (PCR) which detect the presence of HIV viral antigens.
Hope I have shed some light on your query. If you do not have further query you could close the discussion and rate the answer. I will be ready to answer more queries.
Best regards

Above answer was peer-reviewed by : Dr. Shanthi.E
doctor
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Follow up: Dr. Achuo Ascensius (40 minutes later)
Thank you again for your time. I do have a couple of other questions and then I think that should be it.
Though I understand your current answers and will take your recommendation to get retested, could I conclude that it is "possible" that there could be other viral infections that would resemble these type of results similar to HIV testing.
doctor
Answered by Dr. Achuo Ascensius (2 hours later)
Hello,
Thanks once more for the query.

Yes, there are a couple of viral infections that can mimic a positive HIV antibody ELISA test. Such viruses include the Epstein-Barr, Hepatitis, Flu etc.

However, conclusion of a false positive or that the positive result is attributed to other causes rather than the HIV can only be made in retrospect when further testing or retesting proves negative.

Hope this answers your query. If you do not have further queries, you could close the discussion and rate the answer.

Wishing you all the best.

Above answer was peer-reviewed by : Dr. Shanthi.E
doctor
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Follow up: Dr. Achuo Ascensius (40 hours later)
Ok, so last query in this discussion. So, though I do understand that I should follow up with additional testing for confirmation, however, am I also understanding that while not conclusive until further testing, with the above values and information I have provided, i.e. 1.24 abs index value and p55 reading present, it could be "possible" of another viral infection of some sort and not at this point necessarily conclusively HIV?

Thank you.
doctor
Answered by Dr. Achuo Ascensius (36 minutes later)
Hello,

Thanks for writing again.

Yes, for now we can not conclude on a positive result since the confirmatory antigen test P55 was indeterminate. False positive ELISA result would be explained by several factors including ongoing viral infections.

So, to answer your question, yes your result could not be conclusive at this point and a viral infection can produce a false positive.

Hope this answers your query. If you do not have further query, you could close the discussion and rate the answers.

Best regards
Above answer was peer-reviewed by : Dr. Mohammed Kappan
doctor
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Follow up: Dr. Achuo Ascensius (26 minutes later)
Sorry, one more last thought that this last answer from you created. So can I conclude that P55 present, "could be", but is not "definitively" a pre-cursor to HIV? Could be due to another infection?
Thank you again so much for your time.

doctor
Answered by Dr. Achuo Ascensius (5 hours later)
Hello,

As long as you have doubts, I shall always be ready to make the clarifications.

P55 is highly specific and if positive there are high chances (close to 100%) than the result is positive.

All through my previous responses, what I want you to know which is important is that; the initial ELISA you did which were repeatedly positive could be a false positive due to the fact the western blot/P55 were indeterminate and only further testing or re testing will definitely conclude.

Best regards and hope this finally answers your query. If you have more queries, I will be ready to help. If you do not have further query, you could close the discussion and rate the answers.

Best of luck.

Above answer was peer-reviewed by : Dr. Raju A.T
doctor
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Follow up: Dr. Achuo Ascensius (51 minutes later)
Of course very, very unfortunately not the direction of news I have been hoping to hear, however, I appreciate you being very candid with me and the very high likelihood of what possibility I face.
I am just so discouraged that this would have ever been anything that would have crossed my mind to have to deal with in my life and my lifestyle.
I suspect I do need to prepare for direction moving forward for discussions with my doctor on what course of action is best to take.
Thank you for your time and patience with answering my concerns.
Best regards.
doctor
Answered by Dr. Achuo Ascensius (2 hours later)
Hello,

You are welcome at every moment even after this and feel free to write at any time if you want us to talk more. For sure the best thing to do is to hang on with your doctor for support, counseling and directives.

You could close the discussion and rate the answers if you do not have any further query.

Wishing you the very best of luck.
Note: Get personalized answers to your HIV related queries You can choose to talk face to face with your doctor. Book a Video Call now.

Above answer was peer-reviewed by : Dr. Raju A.T
doctor
Answered by
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Dr. Achuo Ascensius

General & Family Physician

Practicing since :2012

Answered : 1040 Questions

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HIV 1/O/2 Abs Test Says Reactive. Western Blot Result Listed As Indeterminate. Due To Viral Infection?

Hello,

Thanks for the query.

HIV 1/O/2 Abs test is an Enzyme-linked immuno sorbent assay (ELISA) test that tests for the presence of HIV types 1 and 2 antibodies in the serum. A threshold value is usually set above which the result is considered positive. This threshold is what is called the index. If the index is taken at 1, all values below 1 will be negative where as values above 1 will indicate a positive results that will require further testing. However, time period after exposure for taking the test matters. Antibody ELISA for HIV won't show positive until after a few weeks.

A value of 1.24 is definitely above 1 and should indicate positive results. But then it’s just fairly above 1 and there are chances it could be a false positive. Several causes have been documented for being responsible for false positives for ELISA. Such factors include naturally occurring antibodies, coded antibodies on the ELISA plates, antibodies against flu causing viruses and other viruses etc.

Confirmation with western blot is indispensable but is also time related and an indeterminate result might indicate that the individual is in sero-conversion especially in people with high risks.

At this point, what would be best would be a repeat of the tests three months later or you do further testing with fourth generation ELISA or polymerase chain reaction (PCR) which detect the presence of HIV viral antigens.

Hope I have answered your query. If you have further queries I will be ready to help. If you do not have further queries, you could close the discussion and rate the answer.

Best regards.