Cost-effectiveness and long-term outcomes of liver transplantation using hepatitis B core antibody-positive grafts with hepatitis B immunoglobulin prophylaxis in Korea

Survival after liver transplantation from hepatitis B-core positive donors at a quaternary care hospital in Brazil

BACKGROUND

Liver transplantation is the treatment for many end-stage liver diseases and hepatocellular carcinoma but shortage of available organs poses significant challenge. Many centers have used grafts from donors with positive anti-HBc serology but concerns about potential hepatitis B virus reactivation and de novo hepatitis B infection have raised questions about the safety of this approach. This study aimed to evaluate the survival of liver transplant recipients from anti-HBc-positive-donors and assess the risk of hepatitis B reactivation and de novo hepatitis B.

PATIENTS AND METHODS

A retrospective single-center cohort study was conducted from 2002 to 2018, comparing who received grafts from anti-HBc-positive-donors to those from anti-HBc-negative-donors. The primary outcome was survival and description cases of hepatitis B reactivation/de novo hepatitis B.

RESULTS

We analyzed 1,111 liver transplants, in which 993 (89 %) received grafts from anti-HBc-negative-donors and 118 (11 %) from anti-HBc-positive-donors. Median age of recipients from anti-HBc-positive donors was 56 years and from anti-HBc-negative donors was of 53 years (p = 0.001). Male sex was predominant in both groups. Factors associated with death in multivariate analysis were retransplantation, early allograft dysfunction, high MELD, recipient over 60 years and female donor. The utilization of grafts from anti-HBc-positive-donors did not increase mortality. The majority of HBV reactivation and de novo hepatitis B occurred in anti-HBc positive recipients. The risk of hepatitis B reactivation/de novo hepatitis B was low and manageable.

CONCLUSION

The study supports safety of liver grafts from anti-HBc-positive donors when employing antiviral prophylaxis. These findings contribute to expand donor options and improve patient outcomes.

Long-term outcomes of active vaccination against de novo hepatitis B among pediatric recipients of living donor liver transplantations with anti-HBc (+) grafts: a retrospective case-control study

BACKGROUND

Active vaccination has been utilized to prevent de novo hepatitis B virus infection (DNHB) in anti-HBc (+) grafts after liver transplantation. However, the long-term efficacy of active vaccination and graft/patient outcomes of anti-HBc (+) grafts have yet to be comprehensively investigated.

MATERIALS AND METHODS

Among 204 pediatric patients enrolled in the study, 82 recipients received anti-HBc (+) grafts. For DNHB prevention, active vaccination was repeatedly administered prior to transplant. Antiviral therapy was given to patients with pretransplant anti-HBs <1000 IU/ml (nonrobust response) for 2 years and discontinued when post-transplant patients achieved anti-HBs >1000 IU/ml, while antiviral therapy was not given in patients with an anti-HBs titer over 1000 IU/ml. The primary outcome was to investigate the long-term efficacy of active vaccination, while the secondary outcomes included the graft and patient survival rates.

RESULTS

Among the 82 anti-HBc (+) transplant patients, 68% of recipients achieved a robust immune response, thus not requiring antiviral therapy. Two patients (2.4%) developed DNHB infection, one of which was due to an escape mutant. With a median follow-up of 150 months, the overall 10-year patient and graft survival rates were significantly worse in recipients of anti-HBc (+) grafts than those of anti-HBc (-) grafts (85.2 vs 93.4%, P =0.026; 85.1 vs 93.4%, P =0.034, respectively). Additionally, the 10-year patient and graft outcomes of the anti-HBc (+) graft recipients were significantly worse than those of the anti-HBc (-) graft recipients after excluding early mortality and nongraft mortality values (90.8 vs 96.6%, P =0.036; 93.0 vs 98.3%, P =0.011, respectively).

CONCLUSION

Our long-term follow-up study demonstrates that active vaccination is a simple, cost-effective strategy against DNHB infection in anti-HBc (+) graft patients, whereby the need for life-long antiviral therapy is removed. Notably, both the anti-HBc (+) grafts and patients exhibited inferior long-term survival rates, although the exact mechanisms remain unclear.

Clinical Significance and Remaining Issues of Anti-HBc Antibody and HBV Core-Related Antigen

Currently, hepatitis B virus (HBV) core antibody (anti-HBc antibody) and HBV core-related antigen (HBcrAg) are widely used as serum markers for diagnosis based on the HBV core region. This review focused on anti-HBc antibodies and HBcrAg and aimed to summarize the clinical significance of currently used assay systems and the issues involved. While anti-HBc is very significant for clinical diagnosis, the clinical significance of quantitative assay of anti-HBc antibody has been reevaluated with improvements in diagnostic performance, including its association with clinical stage and prediction of carcinogenesis and reactivation. In addition, concerning the new HBcrAg, a high-sensitivity assay method has recently been established, and its diagnostic significance, including the prediction of reactivation, is being reevaluated. On the other hand, the quantitative level of anti-HBc antibody expressed in different units among assay systems complicates the interpretation of the results. However, it is difficult to standardize assay systems as they vary in advantages, and caution is needed in interpreting the assay results. In conclusion, with the development of highly sensitive HBcrAg and anti-HBc antibody, a rapid and sensitive detection assay system has been developed and used in clinical practice. In the future, it is hoped that a global standard will be created based on the many clinical findings.

Cost-effectiveness of Kidney Transplantation From Donors at Increased Risk of Blood-borne Virus Infection Transmission

BACKGROUND

Demand for donor kidneys outstrips supply. Using kidneys from selected donors with an increased risk of blood-borne virus (BBV) transmission (hepatitis B virus and hepatitis C virus [HCV], human immunodeficiency virus) may expand the donor pool, but cost-effectiveness of this strategy is uncertain.

METHODS

A Markov model was developed using real-world evidence to compare healthcare costs and quality-adjusted life years (QALYs) of accepting kidneys from deceased donors with potential increased risk of BBV transmission, because of increased risk behaviors and/or history of HCV, versus declining these kidneys. Model simulations were run over a 20-y time horizon. Parameter uncertainty was assessed through deterministic and probabilistic sensitivity analyses.

RESULTS

Accepting kidneys from donors at increased risk of BBVs (2% from donors with increased-risk behaviors and 5% from donors with active or past HCV infection) incurred total costs of 311 303 Australian dollars with a gain of 8.53 QALYs. Foregoing kidneys from these donors incurred total costs of $330 517 and a gain of 8.44 QALYs. A cost-saving of $19 214 and additional 0.09 QALYs (~33 d in full health) per person would be generated compared with declining these donors. Increasing the availability of kidneys with increased risk by 15% led to further cost-savings of $57 425 and additional 0.23 QALY gains (~84 d in full health). Probabilistic sensitivity analysis using 10 000 iterations showed accepting kidneys from donors at increased risk led to lower costs and higher QALY gains.

CONCLUSIONS

Shifting clinical practice to accept increased BBV risk donors would likely produce lower costs and higher QALYs for health systems.

Humoral Immunogenicity to SARS-CoV-2 Vaccination in Liver Transplant Recipients: A Systematic Review and Meta-Analysis

Solid organ transplant recipients generally show reduced immunogenicity to various vaccines. We aimed to assess the immunogenicity of the immune response among orthotopic liver transplant (OLT) recipients after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. A systematic search was performed to evaluate immunogenicity or adverse events reported after SARS-CoV-2 vaccination. The pooled analysis of 20 studies showed a humoral immune response rate of 0.70 (95% confidence interval [CI], 0.63-0.77) after SARS-CoV-2 vaccination among OLT recipients. The immunogenicity among OLT recipients was significantly lower compared to the overall population and healthy controls, with odds ratios (ORs) of 0.80 and 0.69. However, it was significantly higher than that of patients receiving other organ transplants, especially kidneys, with an OR of 1.50. Male sex, old age, chronic kidney disease, obesity, and multiple or high immunosuppressant doses significantly increased the risk of unresponsiveness in patients with OLT. The overall incidence of any adverse event after vaccination was 0.68 (95% CI, 0.55-0.81), similar to that of control. OLT recipients had an overall humoral immune response rate of 70% after SARS-CoV-2 vaccination, which is lower than that of healthy controls but favourable compared to those of other solid organ transplant recipients.