Prophylaxis of Hepatitis B Virus (HBV) Re-Infection in Liver Transplantation: Is the Reappearance of Hepatitis B Surface Antigen (HBsAg) Significant?

The recurrence of hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) was in the past a primary cause of organ loss or mortality. Currently, post-OLT prophylaxis with anti-HBs immunoglobulins plus a nucleos(t)ide analogue has virtually abolished the risk of re-infection. Some studies have proposed to simplify prophylaxis by discontinuing immunoglobulins while continuing the analogue alone. This review analysed the available studies, focusing on the recurrence of HBsAg in serum and its biological effects. In all, 16 studies were retrieved, mainly observational or retrospective, each enrolling 14 to 80 patients. Our review of the literature found that HBsAg re-appeared in 0% to 24% of the patients, generally with HBV DNA undetectable in plasma. One study measured HBsAg using a new ultra-sensitive method, which could allow a reappraisal of the incidence of recurrence. This review discusses the role of HBV surface proteins in inducing hepatocellular carcinoma, particularly when mutations in the C-terminal occur that induce stop-codons that cause defects of secretion and retention of truncated protein S, resulting in direct cell toxicity and cancer. The data on the suspension of immunoglobulins in the prophylaxis regimes of post-transplant re infection do not appear sufficiently robust for an extensive and safe application in clinical practice.