In our centre, we rely on HBV serology: patients with HBsAg positivity are confined on dedicated HD machines and also in independent rooms. Patients that are HBsAb positive or negative get access to the common HD machines. All patients undergo vaccination for HBV when starting dialysis. Although we use a double boosting dose of the vaccine, only part of them develop a specific immune response. We do not use specific measures for HBcAb positive patients.

We perform PCR testin every 3 months in every patient with ESRD on HD. However I am not sure if every patient with pos. PCR needs tratment.

Importance of anti-HBc Ab in dialysis patients:

0 to 20% of them have HBV DNA in their serum, but presence of HBV DNA in he serum is not parallel to infectvitiy. However if the case on dialysis doesn't anti-HBs Ab, it is better to put they away from HBV DNA positive patients in dialysis centers. but it needs to more evidence.

In our practice, we separate patients by the use of dialyzing in a separate area, with designated equipment as well as a designated staff member who is not allowed to also work with other patients whose immunity to Hep B is below acceptable levels.

All equipment is disinfected completely post treatment. The machines istels it chemically disinfected with bleach prior to use for another patient.

I suggest that a very sensitive device, like cobas, can be used to measure HBV DNA no matter if HBsAg is positive in these patients. If anti-HBc is positive, this test become necessary.

I agree with this thesis that we should check the HBV DNA in patients with HBs Ag negative but anti-HBc Ab positive in hemodlaysis setting, but in countries with low resources it is impossible to dedicate the machines in dialysis.

I think the issue does relate to resource availability however if the patient has "occult HBV" i.e. detectable DNA, then as with the blood transfusion services who exclude these patients as donors, the same should then apply to HD patients viz. they should be dialyzed separately. This does not preclude the aggressive pursuance of ensuring hep B vaccination of HBV negative (HBsAg and HBcAb negative) patients on HD.

The CDC proposes that patients with positive HBV DNA, but with negative HBsAg are not infecting and, therefore, do not need the be confined on dedicated HD machines and also in independent rooms and designated staff member. Patients with occult HBV can transmit and infect in blood transfusion and experimentally they are able to infect monkeys. Actually, in a hospital unit were patients with acute and chronic renal failure are dialyzed, we are measuring HBV DNA 6 times a year. This year we were able to document a patient with a positive Anti HBs that became positive to HBV DNA. This patient was separated from the others until the DNA became negative. No other conversion or reactivation were seen. Occult HBV may be partially responsible for the 1% of serumconversion to HBV seen annually in the hemodialysis unit in USA

Evaluation of the impact of HBV infection in producing liver injury among hemodialysis patients should perform serially during a year by checking PCR HBVDNA and fibroscan.There is no Evidence-based consensus to treat HBV infection in terms of cutoff values for the mentioned tests among these patients.

Dedication of dialysis machine depends on resources,HbsAg levels and titer of HBVDNA .

We check HBV serologically every 3 months in our hemodialysis patients.We also use vaccination.The HBV positive patients are put in dedicated machines and room, but not separated staff.The staff should be very careful by itself.The application of HBV treatment depends on the case and a such desicion is always in a great discuss.

I agree with Dr Mostafa Alavi-Moghaddam. If you have enough resources in your centre then better to designate a machine for them. Being PCR positive does not mean patient need therapy, other variables including Biopsy result, ALT and AST level are also important to make a decision for therapy.

We do dedicate hemodialysis machines as suggested by CDC guidleines and as being widely peracticed.

Re. tratment, one should do a liver biopsy specially in potentioa kidney transplant ecipients, and depending upon the severity of the disease, we decide to treat or not to treat. our hepatologist usually makes this decision.

I do agree with what Mostafa has mentioned, where I believe that they might carry the risk of transmitting it to non infected persons though this can be reduced or may be avoided by vaccination and prohibiting dialyzer reuse

I think that the possibity to transmit HBV disease by "very occult HBV patients" is very rare in hemodialysis patients.

All the patients in hemodialysis contest should be vaccinated for HBV infection in particular the patient with HCV RNA positivity.

I cvonsider antiviral therapy for Occult HBV only in patients that have to take steroid or immunosuppressant drugs.

Giorgio Soardo MD University of Udine Italy

In our opinion, HBcAb positive patients, independently of the presence of HBV DNA, treated by significant and prolonged immunosuppressive regimens (anti-CD20 mab, cyclophosphamide) need a prophylaxis with lamivudine (100 mg/day).

I've personally observed a few cases of seroconversion of such patients, with reactivation of HBV and a rapid fatal course, especially in the setting of anti-CD20 mab therapy for hematologic malignancies.

I agree with the comment of Vincenzo Montinaro. lamivudine prophilaxis is a good choise because LAM is more efficacy and low expensive.

Do you have a control group oh anti-HBcAg positive patients who did not undergo lamivudine prophylaxis? Is the prevalence of HBV DNA appearence in the serum really higher than in subjects treated with lamivudine? And what about literature in this topic?

It is different in hemodialysis patients and they did not need to therapy

To Enzo Ierardi question: I personally am not aware of robust published evidence in favor or against lamivudine prophylaxis in this setting. In my experience I have not observed a structured control group. Yet, I recall at least four cases of fatal reactivation of Hep B in patients under immune suppression. In 1 case, the patient was treated by steroids and azathioprine.

Dear Vincenzo: interesting and impressive your clinical experience about occult B hepatitis in hemodialysis patients. However, the problem is hemodialysis or immunosuppressants? In this second case we must think to lamivudine prophylaxis in all patients treated with anti-TNF alpha, for example. This is not indicated by actual protocols, but may stimulate intersting trials in the future. Indeed, despite guidelines, "the answer" is not ready.