Kidney Transplantation from Donors with Resolved HBV Infection: Minimal but Potential Transmission Risk and the Need for Improved Recipient Vaccination.

Background/Objectives: Hepatitis B virus (HBV) transmission risk from donors with resolved HBV infection remains a concern in kidney transplantation, because covalently closed circular deoxyribonucleic acid (DNA) may persist despite serological recovery. In this study, we evaluated the transmission risk from anti-hepatitis B core antibody (anti-HBc)-positive, hepatitis B surface antigen (HBsAg)-negative, and HBV-DNA-negative living donors to anti-HBc-negative recipients. Methods: We retrospectively reviewed living-donor kidney transplantations performed at our institution (June 2011-December 2024). Among 277 transplantations, 26 met the inclusion criteria. All recipients had received HBV vaccination prior to transplantation. Serological markers, including HBsAg, anti-HBc, anti-hepatitis B surface antibody (anti-HBs), and HBV-DNA, were monitored before and after transplantation. Results: Five recipients (19.2%) achieved anti-HBs seroconversion after vaccination pre-transplantation, but all lost protective antibody levels before or shortly after transplantation. Five recipients (19.2%) showed transient post-transplantation anti-HBs positivity; three cases were considered vaccine-related, and two were possibly transplant-related. None of the patients developed liver enzyme elevation, clinical hepatitis, HBsAg positivity, or anti-HBc seroconversion. Among the four recipients tested for HBV-DNA, all results remained undetectable throughout follow-up. None of the recipients maintained protective anti-HBs levels pre- or post-transplantation, despite universal vaccination. Two recipients (7.7%) developed delayed anti-HBs positivity without anti-HBc seroconversion, HBsAg positivity, or detectable HBV-DNA, suggesting possible subclinical HBV antigen exposure from the allograft. Conclusions: Kidney transplantation from donors with resolved HBV infection was not associated with clinically evident HBV infection, although transient serological changes were observed. Optimized vaccination strategies and structured post-transplant monitoring may enhance the safety of transplantations involving such donors.