Early hepatitis B and delta virus kinetics in patients undergoing liver transplantation

HBV recurrence after liver transplantation (LT) can occur despite removal of the infected liver and antiviral prophylaxis. Timing and mechanisms of HBV and HDV recurrence remain unclear. We evaluated post-transplant viral kinetics to address this gap. Twelve HBV patients undergoing LT, including five with HDV-coinfection, were prospectively enrolled. Serial serum and liver samples were rigorously collected before, during, and post-LT to characterize viral kinetics. HBV-DNA, HDV-RNA, HBsAg, and HDAg were detected in all explanted livers, whereas cccDNA was found only in HBV-monoinfected patients. Serum HBV-DNA, detectable in five recipients before LT, became undetectable within hours from LT. In HBV-monoinfected patients, baseline HBsAg levels were low (< 3logIU/mL) and cleared rapidly after LT, with faster disappearance in those receiving HBIG (5 days vs. 6 months). Among HDV-recipients, all treated with HBIG, HBsAg clearance was rapid when baseline HBsAg levels were <3log₁₀IU/mL (12 h) and delayed at higher levels (6 months). HDV-RNA kinetics paralleled HBsAg decline. Post-transplant liver biopsies (reperfusion, 3- and 12-months) tested negative for viral markers, except for isolated intrahepatic HDV detection at 3-months in one patient. No intrahepatic HBV reinfection was observed post-LT. Occasional intrahepatic HDV detection supports the need for improved prophylactic strategies in HDV-recipients.