Respected community members,
I have some questions and I would very much appreciate your help here.
July 2023, my anti-hbs level was 1000.00 miu/ml, antihbc positive, hbsag negative.
August 2024, my anti-hbs level is 708.00 miu/ml.
I would like to know is this a significant decline in anti-hbs level over the course of 1 year, and what could trigger such a loss of protective antibodies?
Please help me, I need some explanation.
I am a 37 yrs old female, I gained natural immunity from previously resolved infection, found it out by chance, I dont know when it happened. My overall health is ok, no major issues, but I do stress myself a lot, I have high blood pressure, no diabetes, 3 months ago CBC and thyroid enzyms were in normal range. I do have stomach issues, regarding digestion.
Since August 2023 till February 2024 I was frequently exposed to HBV through unprotected sexual contact with my partner who is an inactive chronic hep b carrier with low viral load (his viral load is 500- not sure about the units, and he has been in inactive carrier state for years), although we always used pull-out method, not sure if this decreases the risk of exposure.
9 weeks after my last exposure (around the middle of April 2024) my liver enzyms were normal, liver ultrasound was normal and bilurubin was normal, blood sugar and cholesterol were normal, CBC was normal, thyroid markers were normal.
25 weeks after my last exposure (which is now, August 2024) I did anti-hbs and it is 708 miu/ml.
Is this a significant drop in antibody levels?
What could be the cause?
Am I still protected? If anti-hbs is 708 miu/ml 25 weeks after the last exposure, does it mean that im still protected and that my hbsag is negative?
Please help! I am just afraid and freaking out bcz with this speed it seems as if I will lose all my protective antibodies in a year or so.
Thank you so much
@ThomasTu
@availlant
@john.tavis
@PLampertico
And other respected members of this community.
Dear @Layla_mac,
Antibody levels naturally rise and fall over the course of time. They go up when the immune system is exposed to the antigen against which it is making antibodies, and slowly go down when that exposure goes away. That is the principle behind “booster” shots of vaccines.
I cannot say this for sure, but my impression is that your immune system was being repeatedly stimulated by low level exposure to HBs from your partner, and that stimulation went away when you ceased having relations with him. That may well be the cause for the reduction in anti-HBs antibodies.
Your antibody levels are still very high. Levels >10 mIU/ml are typically considered protective (this threshold varies somewhat), so you should still be protected.
If you are concerned, you can ask your physician for an HBs booster vaccination. That is very safe, but in many countries you’d have to pay for it yourself as insurance might not cover it given that you already have high antibody levels.
I hope this helps.
John.
Thank you so much for sharing your expertise and opinion!
Hopefully I will hear other’s opinions as well.
Thank you.
This is not a significant decline, you are still protected
Regards
Prof. Pietro Lampertico, MD, PhD
Full Professor of Gastroenterology
Chief, Gastroenterology and Hepatology Division
Foundation IRCCS Ca’ Granda Ospedale Maggiore Policlinico
Director, CRC “A. M. and A. Migliavacca” Center for Liver Disease
Department of Pathophysiology and Transplantation
University of Milan
Via Francesco Sforza 35
20122- Milan
Italy
Phone +390255035432
Fax +390250320410
Thank you so much for your output, Prof. Pietro!
Respected @ThomasTu
@john.tavis
@availlant
@PLampertico
If my antihbs level is 708 miu/ml 25 weeks after the last exposure, does it mean that the hbsag is negative? Are these two mutually exclusive?
Thank you!
Hi @Layla_mac,
That is actually a bit of a complicated question! The standard clinical assays measure free HBs and free anti-HBs (free means not bound to anything else), so those assays are almost always mutually exclusive. However, that does not necessarily mean that a person is making no HBs. This is because HBs and anti-HBs form very stable complexes, and those complexes are not detectable by the standard clinical assays. They can be detected using research-level assays, so we know they are there. I do not know if there is any clinical significance related to the level of HBs:anti-HBs complexes.
John.
Respected,
Thank you for your output, I really appreciate!
For an alternative opinion: Sexual relations with someone with a viral load of about 500 using the pull out method could not feasibly provide someone with significant enough viral exposure to increase their antibodies. So the small decrease would just be a meaningless fluctuation
In general, hbsag is negative when antihbs are high but not always
Hi @Bob,
This is not necessarily true for an established immune response.
First, the antigen stimulating the antibodies is almost certainly subviral HBs particles, which are present in a vast excess over DNA containing viruses, and the HBs level can be independent of the virus level as HBV integrants into the host genome can efficiently make HBs. Second, It takes just a trace of antigen to stimulate the immune system once it has developed a mature response, and the net effect could be cumulative from multiple stimulation events.
That being said, my comments were just speculation, and the relatively small change in antibody titer could easily be natural variation. We just cannot tell for sure. Medically, it is irrelevant as the antibody titers are still high.
John.
Fair enough. I think it’s important to elucidate that it could be (non infectious) subviral particles stimulating the antibody response, to avoid people walking around with the mental model of infected people going around contaminating everything they touch