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Inconclusive Results, ARS, Braces

Question: 

Hi,

I recently was tested for HIV and when my results came in I was called into the testing clinic. These were the results:

HIV 1/2 Ag/Ab Combo Screen: Reactive
HIV 1 p24 Antigen Screen: Non-reactive
HIV 1 Western Blot: Negative
HIV Final Interpretation: No HIV p24 antigen detected; inconclusive for HIV1/HIV2 antibodies

I have had two sexual partners in my life. With one we only had oral sex. With the second more recent one we had sex twice and used a condom both times (10 weeks prior to the first test) and the person that I had sex with said that he had been tested and was HIV free prior to sex. I am gay and was bottoming. Based on my history I questioned the result and immediately went for point of care rapid testing. The test came back negative and the doctor said that he questioned the initial result, thinking that there may be a non-HIV antibody in my blood triggering a false positive. However, he told me to abstain and sent off my blood for additional testing. I have about a week to go before I hear back. I have a few questions:

1. I have braces and I kissed someone deeply three weeks before the first test. Could I have contracted HIV in this way?
2. I have had cold/flu symptoms and swollen glands on and off for the past 3 or 4 weeks. Could these be symptoms of ARS? The symptoms seemed to be resolving and then worsened with the stress from the news of the first test.
3. What is the HIV 1/2 Ag/Ab Combo Screen? Is this the same as ELISA? How does it differ from the other tests that came out negative? What could lead to a false positive on this test?

Any info that you could provide me with would be great. Thanks.

Answer: 

Hi and welcome to the Helpline,

It's great to hear that you're being proactive about getting tested. It sounds like you're wanting a bit of clarification before you go back to see your doctor.

To answer your first question, no, whether you have braces or not, it is not possible to acquire HIV through deep kissing. As for your symptoms, it's really not reliable to go by symptoms when diagnosing HIV. ARS symptoms are different for everybody, and some people don't get symptoms at all. The only thing you should be looking at to determine your HIV status is your test results.

Regarding your third question, the HIV 1/2 Ag/Ab Combo Screen is a 4th generation test. The ELISA is a 3rd generation. The 3rd generation test looks for antibodies in the blood, and where the 4th generation looks for antibodies too, it also includes a P24 antigen test. That's why it's often referred to as a "combo" test; It looks for both antibodies and antigens. The P24 antigen is detectable immediately after infection and only for the first few weeks, whereas most people develop detectable antibodies after 21-25 days. Because some individuals take longer to develop detectable antibodies, tests are considered conclusive at 12 weeks post-exposure (although 95% of infections are detectable within 4-6 weeks). Most HIV specialists actually consider the 4th generation test to be conclusive at 6 weeks, however. Though, HIV testing guidelines still recommend re-testing at 12 weeks for completely conclusive results.

False positives do happen, however I cannot speculate on what may have lead to a false positive on your test as I am not a doctor. Your doctor is an expert and will know best here, and his thinking that there may be a non-HIV antibody in your blood triggering a false positive is very reasonable. This is a great question to ask him/her when you go back to the clinic.

Something to comment on, the Western Blot test is considered to be "gold standard" for confirmation of HIV infection. The accuracy for this test is 99.9% after 4-6 weeks. Since you said your last possible exposure was 10 weeks prior to the first test, your negative result for this is highly unlikely to change. This is a great indicator that you are indeed HIV negative.

One more thing I would like to comment on... while your symptoms may not be related to HIV, if they are bothering you they are still something to get checked out by a doctor. They could be a sign of something else going on. You may consider bringing them up with your doctor if you are concerned still.

I wish you the best for when you hear back from the clinic this week. If you have any more questions please don't hesitate to post again.

Sabina

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