EXPLAINER: Lab results and their interpretation

What do my lab results mean?
1282

Hi everyone. I am trying to understand my lab results and make sense of my diagnosis and appreciate everyone who is contributing to this community.

Two weeks ago, I tested positive for hep B surface antigen. It was routine testing for work. In 2017 I had immunity (hep B surface antibody) and then in 2018 my immunity level read “equivocal” at that time.

I asked to get the Hep B vaccine again two weeks ago since the last time I was tested my immunity was equivocal. I got the vaccine and then 30-40 minutes later they collected my blood for the Hep B surface antigen.

I have a few questions if anyone knows the answer:

1- if I was just vaccinated for Hep B 30 minutes before they drew my blood for the Hep B surface antigen, is it possible that it altered the test?

2- I was told if you are ever immune for Hep B you are considered immune for life. Wouldn’t it be very unlikely that I am infected with Hep B?

Thank you in advance. This information has been causing me a lot of anxiety and I would love to hear what other people think of my situation

1283

Hi @Wexersville,
Welcome to the community and thanks for your questions. First, I don’t think the vaccine is going to impact your HBsAg test. The vaccination would not even impact your antibodies, since that will develop over weeks after vaccination.

For, the second question your results being equivocal means it could neither be interpreted as positive or negative. Do you have the value for your HBsAb test? It is possible to have HBV because for work screenings they only do tests for HBsAb at least in the US. They do not screen for HBsAg. In my case because I did not have immunity I was vaccinated. But all that while I already have HBV but because a surface antigen test was not part of the work panel tests ordered I received the shots for my work. I did find out some years later when a surface antigen test was done that I had the virus all those years.

You are correct, for most people (90% or more) immunity lasts for life, but for a small group they will need a booster from time to time when their protection wanes down.

So it is possible that you had the virus already and was still vaccinated which in this case will not lead to immunity or production of antibodies. Or there may be some false positives or negative tests here. I empathize with you regarding having anxiety. Take it easy, one day at a time. You will untangle this mess of results. Bansah1

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1284

Thank you for your reply. I appreciate you sharing your experience. This is the first time I have ever been tested for Hep B surface antigen. I agree that usually the testing that is done is only for immunity not infection. I am a health care worker so I am, of course, worried that this could be related to a workplace exposure that I wasn’t aware of.

I have been doing some of my own research and have found a few sources that say that Hep B antigen should not be drawn within 4 weeks of vaccination. (Immunize .org) I have been trying to get a clear answer from a doctor about this and I have not been successful.

I saw a lot of really smart discussion on this page and thought I would try to see if anyone here has any information about this. I’m waiting to get an appointment with another doctor for more tests. I had been weeks since my reactive antigen test and I’m not closer to getting any answers.

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1285

You are welcome and thanks for reaching out. I know you don’t do antibody test right after vaccination because it will be too early for the body to develop or produce antibodies then. I am not sure why they think vaccine could affect the antigen test.

I hope other experts can chime in on this. Sorry you have to go through this web of confusing results. Keep us posted. Bansah1

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1286

Dear @Wexersville,

Welcome to the forum and thanks for the great question. It correct that false-positive HBsAg results can occur after vaccination, particularly when blood is taken soon after getting your vaccination (as happened in your case). Several cases have been described in the literature:

If indeed you were anti-HBs positive to protective levels in 2017 (>10mIU/mL), then it is more likely that this represents a false positive. It is worth following up these blood tests at least a couple of weeks after your booster vaccination with the whole panel of HBV markers (anti-HBs, HBsAg, and anti-HBc).

Hope this helps,
Thomas

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1287

Yes that helps a lot, thank you.

I have a doctors appointment next week and am going to ask for more labs to follow up. The hardest part has been that the doctor who ordered these tests at my work place delivered the Hep B diagnosis and has not helped me get any further testing. I’ve been asking questions and been told they can’t help me any further, which has been so frustrating. Thank you for sharing your knowledge with me. I have felt so alone in this processes so just being listened to here has made me feel much better.

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1288

I was able to get some follow up testing 13 days after I was vaccinated for hep B:

My Hep B surface antigen was reactive again.
Hep B surface antibody was positive >1000 for immunity.
Hep B core antibody was negative.

If the core antibody is negative, is that indicative that I do not have Hep B and the positive antigen is due to recent vaccination?

Thanks for your help

1289

Hi @Wexersville,

Thanks for keeping us all up to date with your results.

While in many cases HBsAg does go away a couple of weeks after vaccination, there have been reports of HBsAg being detectable for up to 38 days after vaccination (Transient Hepatitis B Surface Antigenemia Following Immunization with Heplisav-B - PMC).

Given your high levels of anti-HBs and negative anti-HBc result, it would be pretty likely that this represents a false-positive result for your HBsAg. However, to be sure, you should repeat the test in a few weeks to check and consult with your physician.

Hope this helps,
Thomas

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1290

Dear Communtiy,

It is with resources like this that we can aid our journey with this disease. I’m eternally grateful for all you.

I would love some feedback on the following lab work.

HBsAg
Tested positive Jan.7 (part of 10panel sti test I do every 12 months)
Tested negative Jan. 8 (stand alone test)

How is this possible?

Hepatic panel - perfect Jan. 8, perfect 3 months ago, 7 months ago, 12 months ago.

No symptoms

Vaccinated 20yrs ago.
Waiting on additional tests from primary doctor. May take a while.

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1291

Hi @James1,
Welcome to the community. Either a false positive or a negative result is possible here. Don’t be surprised because they do happen at times. I suggest you do HBsAg with confirmation and HBsAb. If your results show that HBsAb is positive, then it will prove that the HBsAg results are false. Best, Bansah1

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1292

hi @Bansah1

Thank you so much for your reply

Just received third test results.

HBsAg Negative (today - third test)

HBsAb Negative (was vaccinated 2x 20yrs ago - immunity worn off)

Still waiting on HBeAg.

Is it possible to be HBsAg negative but HBeAg positive?

Very grateful for your insight!

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1293

HBsAG I just got back was with confirmation. (3rd test) - 1st positive, subsequent 2 negative.

1294

Hi @James1,
HBeAg positive only indicates active viral replication and infectivity. On the other hand, HBsAg positive indicates that one is infected with HBV. It is unlikely to be HBsAg negative (no infection) but HBeAg positive (has infectivity and replication of a virus one doesn’t even have). In your case, it looks like you need to be vaccinated again since you only completed 2 shots instead of 3 (20 years ago) if I understand you correctly. I hope this helps. Bansah1

1295

Hi @james1,

Welcome to the forum and sorry you have been through the stress of uncertainty about your situation.

Indeed, the results you have posted are consistent with a false positive for HBsAg. It is worth getting other tests to confirm this, including an anti-HBc test (to test for previous exposure).

It may also be worth getting a booster for HBV, so that you have the peace of mind that you are protected in cases of future exposure.

Hope this helps,
Thomas

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1296

Hi @Bansah1

Thank you so much for the perspective. Yes, it most certainly helps.

And will get vaccinated again ASAP.

Will discuss with my primary if he requires any more HBsAG before I proceed to vaccination.

Based on last two negative HBsAG, the first positive notwithstanding, I will proceed as though I’m negative.

Would assume the first was a false positive? Or would you recommend I consult with a specialist?

Thank you so much for the advise!!!

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1297

@ThomasTu ,

Thank you so much, Thomas.

anti-Hbc also came back negative.

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1298

Hi @James1,
You are welcome. Yes, your assumption is correct. At this point with 2 negative tests, I think it is more likely the first was a false positive. Get the vaccine now, and then after 2-3 months check anti-HBs. If it is positive then it confirms the negative test was correct. Best, Bansah1

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1299

I agree with @Bansah1 that the first one was likely a false positive, particularly given your anti-HBc is negative also.

TT

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1300

@ThomasTu @Bansah1,
Very much appreciate your feedback and am very grateful for your respective perspectives.

How common are HBsAg false positives?
Controlling for recent vaccination, ofc.

Have been going over different threads here and did some research online and seemingly very little information on the subject.

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1301

Hi @James1,

The false positive rate will be dependent on the specific test used, and there are several kits used globally to measure HBsAg. The false positive rates can be found with some digging (in the kit paperwork or in the studies needed to be carried out for appropriate approval for use in the clinic).

Sorry, I can’t be more specific without more information.

Cheers,
Thomas

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