Dear Sir,

Regarding this history, it looks like he is a carrier of HBV with low-level HBs Ag level, specially if he is still negative for HBs Ab after vaccination.

Dear Dr. Mohsen Nassiri-Toosi

Thank you so much for a quick answer. I agree with you that he is diagnosed with occult HBV infection. He is still negative for HBsAb. Why is he negative for HBsAb?

Dear Dr.Takegoshi,

The situation appears a bit complicated but going by virologic profile first IgM and IgG HBcAb needs to be done to exclude recent acute hep B infection (in which case IgM will be positive) which is in the process of clearing. The other possibilities are (A) patient is harbouring a mutant strain of hep B virus for which he is negative for all the usual immunomarkers, (b) exclude Congenital or acquired causes of immunodeficiency, (c) test the immunogenicity of the vaccine strain

Dear Dr.Gautam Ray

Thank you so much for  a critical answer. He is negative for anti-HBc-IgM. It seems he is not diagnosed with acute HBV infection. Although no HIV nor other markers for immunodeficiency has been surveyed, he is well and quite healthy. As for the HBV vaccination, at first, he recieved three times' genotype C-derived vaccine (Bimmugen, 0-1-5 months). And as he was negative for HBsAb, he recieved additional four times' genotype A-derived vaccine (Heptavax, 0-1-1-1 months, intramuscular). As a result, he is negative for anti-HBs. Mutant HBV, very difficult?

Thanks for the reply. In such case uncommon mutant is very likely. Sometimes HBsAg of such mutant virus is  not picked up by the commonly used  HBsAg assay.

I think this patient has acquired HBV infection in neonatal or childhood period, which the immune system has not well developed to clear the virus, and became a carrier. There is no consensus for his follow up, it will be safe side to follow as an inactive carrier state.

Four explanations: a) recent hbv infection, b) very low levels of HBsAb, c) HBcAb false-positive, d) chronic infection with very low levels of HBsAg (CDC, Hepatitis B, Epidemiology and prevention of vaccine-preventable diseases. 13th edition, 2015). I recommend: A systematic reviewand meta-analysisof management optionsfor adults who respond poorly to hepatitis B vaccination, David M et al, Vaccine 2015, 33: 6564-6569. 

Dear Dr.Nassiri-Toosi, Dr. Ray, Dr. Saberifiroozi and Dr.Otero

Thank you so much for the suggestions. I have to inform you that he and his wife (HBeAg+, HBV-DNA>9.0, ALT 15) married one year and 8 months ago. And his wife visited to a Gynecologist due to abortion (9 weeks) one year and two months ago. He visited to our clinic one year ago for HBV vaccination. At that time, he was negative for HBsAg and HBsAb (ALT 26). It revealed he is positive for HBcAb/HBeAb but negative for HBsAg/HBsAb this month. As you all indicated that he is infected with HBV (occult HBV infection), I will advice him  not to worry about new HBV infection by his wife.

I think that the patient is not harbouring a mutant strain of B virus otherwise we should had found a positive HBV-DNA (a mutant strain of HBV is a false occult).

For shure he is a subject with a previous HBV infection (anti HBc and anti HBe pos).

The most accreditated hypothesis is that the subject is experiencing a long period of sieroconversion (he has cleared the virus but, as occurs in previous chronic carriers, it takes a long period to complete sieroconversion).

In my opinion he is not completely protected from a new viral load.

Dear Dr. Barone

Thank you so much for giving me your thought.  I would appreciate it.

Judging by the information provided, it seems likely that he is partially but not fully protected from HBV. Unless he is anti-HBs positive, then he will be fully protected. As it is now, the HBV DNA is negative and that is a big plus for him.  He look most likely like someone who was previously infected, hence the presence of anti-HBc and anti-Hbe with the absence of HBsAg and anti-HBs, this look like a good sign of recovery from the infection and stand the chance of not degenerating to liver cirrhosis/ or hepatocellular carcinoma.

Dear Dr. Martins Ayodele

Thank you so much for giving me your thought. I understand he will not be fully protected from new HBV infection. However, as his wife has once experienced abortion, namely his unmatured children, I permitted him to have his new baby.

I think he might have occult hepatitis B infection.