Academy Exchange

I'm an NP and new HIV provider and have assumed care of number of patients who have (+)HepBsAb and (-)HepBsAg on file but have never had a HepBcAb checked. I've been trying to obtain HepBcAb testing in these patients to look for evidence of past infection, and thus the need to counsel on risk of reactivation in the future. It's been recommended to me that after a (+)HepBcAb in the setting above, I should recheck a HepBsAg or even a Hep B viral load. However, I don't understand the rationale for these additional tests given historic immunity. Most of the patients are on ART which would cover Hepatitis B. I'm hoping for guidance & rationale on what additional testing is recommended in the situation above?

Thank you, Emily

Hi Emily.

You're right, checking the HepBcAb differentiates between people who have been infected with Hep B and people who have been vaccinated, so it's important information. What can happen in people who have been infected with Hep B is if the surface antibodies were positive in the past, but the patient's health has changed (stopped their ART, we're treated with some biologic drugs, switched over to a regimen that doesn't contain tenofovir, etc) they may no longer be effectively controlling the Hep B infection. To make my life easier, I just send the whole panel if I'm looking for history of infection (sAg, sAb, cAb), and only check the sAb, sAg separately if I'm following for resolution of infection. I would only check a HBV viral load if the surface Antigen is positive. 
Anecdotally, I had a patient who was previously infected, had a negative sAg, positive sAb, cAb, who stopped his ARV due to an SUD relapse. When he came back into care, his CD4 had dropped, but was still >200, his HIV viral load was in the 100k range, and his Hep B sAg was now positive, with a viral load of 34 million. It took about 5 years on HAART, but he's finally back to having a negative sAg, and positive sAb. Doesn't happen often, but that's why people are recommending the OCD testing.
These days more patients are on regimens that don't necessarily treat Hep B (Dovato, Juluca, Cabenuva, and Triumeq don't contain tenofovir), and more people are getting biologic agents to manage other health problems, so knowing who was vaccinated and who was previously infected is important.

hope that helps, Edie