Low-dose anti-hepatitis B immunoglobulin regimen as prophylaxis for hepatitis B recurrence after liver transplantation

Microbiota and Immunity during Respiratory Infections: Lung and Gut Affair

Bacterial and viral respiratory tract infections are the most common infectious diseases, leading to worldwide morbidity and mortality. In the past 10 years, the importance of lung microbiota emerged in the context of pulmonary diseases, although the mechanisms by which it impacts the intestinal environment have not yet been fully identified. On the contrary, gut microbial dysbiosis is associated with disease etiology or/and development in the lung. In this review, we present an overview of the lung microbiome modifications occurring during respiratory infections, namely, reduced community diversity and increased microbial burden, and of the downstream consequences on host-pathogen interaction, inflammatory signals, and cytokines production, in turn affecting the disease progression and outcome. Particularly, we focus on the role of the gut-lung bidirectional communication in shaping inflammation and immunity in this context, resuming both animal and human studies. Moreover, we discuss the challenges and possibilities related to novel microbial-based (probiotics and dietary supplementation) and microbial-targeted therapies (antibacterial monoclonal antibodies and bacteriophages), aimed to remodel the composition of resident microbial communities and restore health. Finally, we propose an outlook of some relevant questions in the field to be answered with future research, which may have translational relevance for the prevention and control of respiratory infections.

High-potency nucleos(t)ide analogues alone or plus immunoglobulin for HBV prophylaxis after liver transplantation: a meta-analysis

BACKGROUND

The optimum prophylactic regimen against hepatitis B virus (HBV) recurrence after liver transplantation (LT) in HBV-infected patients is uncertain but of great clinical relevance. New evidence suggests that hepatitis B immunoglobulin (HBIG)-free approach would become a reasonable choice in the era of high-potency nucleos(t)ide analogues (HPNAs). We aimed to provide robust estimates for long-term survival and HBV recurrence in patients receiving different HBV-prophylaxis strategies after LT.

METHODS

We did a systematic review and meta-analysis using both pseudo-individual patient data recovered from included studies (IPDMA) and conventional trial-level aggregate data meta-analysis (ADMA). Hazard ratios (HRs) were calculated using different Cox proportional hazard models accounting for inter-study heterogeneity. ADMA was conducted to pool outcomes at specific time points.

RESULTS

A total of 16 studies involving 7897 patients and 41 studies involving 9435 were eligible for IPDMA and AMDA, respectively. Cumulative HBV recurrence rate and overall survival (OS) at 1, 3, 5 and 10 years post-LT were 0.3%, 0.9%, 1.2%, 1.7% and 95.6%, 89%, 86.4%, 86.4% in the HPNAs (i.e., entecavir and tenofovir) + HBIG combination group vs. 0.6%, 0.6%, 1.2%, 1.7% and 94.5%, 86.8%, 84.8%, 81.2% in the HPNAs monotherapy group (HR 1.20, 95% CI 0.56-2.60, p = 0.64; HR 1.09, 95% CI 0.70-1.69, p = 0.72), respectively. The results were compatible with AMDA.

CONCLUSION

A similar HBV recurrence and overall survival were found in patients who used HPNAs (mainly entecavir) monotherapy as in those who received a combination of HPNAs and HBIG. These findings address concerns regarding the safety and effectiveness of HPNAs monotherapy.

Entecavir Combined With Short-term Hepatitis B Immunoglobulin in Preventing Hepatitis B Virus Recurrence in Liver Transplant Recipients

BACKGROUND

The combination of nucleoside analogs and long-term hepatitis B immunoglobulin (HBIG) is considered to be the standard regimen for preventing hepatitis B virus (HBV) recurrence after liver transplant (LT). However, long-term use of HBIG causes many adverse effects. The aim of this study was to evaluate the effect of nucleoside analogs entecavir combined with short-term HBIG in preventing HBV recurrence after LT.

METHODS

This retrospective study assessed the effect a combination of entecavir and short-term HBIG in prophylaxis of HBV recurrence among 56 LT recipients who had undergone the procedure because of HBV-associated liver disease at our center between December 2017 and December 2021. All patients received entecavir treatment combined with HBIG for the prevention of hepatitis B recurrence, and HBIG treatment was withdrawn within 1 month. The patients were followed up to determine levels of hepatitis B surface antigen, antibody to hepatitis B surface antigen (HBsAb), and HBV-DNA and the recurrence rate of HBV.

RESULTS

Only 1 patient appeared positive for hepatitis B surface antigen at 2 months post-LT. The overall HBV recurrence rate was 1.8%. The HBsAb titers of all patients gradually decreased over time, with a median of 376.6 IU/L at 1 month post-LT and a median of 13.47 IU/L at 12 months post-LT. During the follow-up period, the HBsAb titer of the preoperative HBV-DNA-positive patients remained at a lower level than that of HBV-DNA-negative patients.

CONCLUSIONS

Entecavir combined with short-term HBIG can exert a good effect for the prevention of HBV reinfection post-LT.

Antiviral prophylaxis against hepatitis B recurrence after liver transplantation: Current concepts

The advance in treatment against hepatitis B virus (HBV) infection with the development of nucleos(t)ide analogues (NAs) with high genetic barrier to resistance, including entecavir and tenofovir, has improved clinical outcomes of patients transplanted for HBV infection, by preventing HBV recurrence after liver transplantation (LT) effectively. Currently, after LT, the combination of hepatitis B immunoglobulin (HBIG) and a high-barrier NA is considered as the standard of care for prophylaxis against HBV recurrence. However, because of the high cost of intravenous high-dose HBIG, other routes of HBIG administration, such as intramuscular or subcutaneous, have come to the foreground. In addition, several transplant centres tend to use a NA as monoprophylaxis, following a short post-LT period of HBIG and NA combination. Lately, studies using HBIG-free prophylactic regimens with entecavir or tenofovir have shown promising outcomes in preventing HBV recurrence, mostly regarding patients with undetectable HBV DNA at the time of LT. Although vaccination against HBV has been an attractive prophylactic approach, its efficacy has been controversial. Moreover, further studies are needed regarding long-term outcomes of complete withdrawal anti-HBV prophylaxis. For patients transplanted for HBV/HDV co-infection, combined regimen should be administered for a longer period post-LT. Finally, the use of grafts from hepatitis B core antibody-positive donors is safe for HBV-negative recipients, with the administration of lifelong antiviral prophylaxis.

Prevention of HBV Recurrence After Liver Transplant: Long-Term Results

BACKGROUND

Antiviral therapy with or without hepatitis B immune globulin (HBIG) is a common strategy for the prevention of hepatitis B virus (HBV) reinfection. But there is no consensus on management protocols, and long-term data are relatively rare on recurrence of HBV infection after liver transplantation using a nucleoside analogue and HBIG prophylaxis.

METHODS

We performed 56 liver transplants since June 2006. Among them, 32 liver recipients had liver cirrhosis associated with HBV, 9 with hepatocellular carcinoma (HCC), and 23 without HCC. Three operative mortalities, 3 deaths within 1 year related to infection, and 1 follow-up loss less than 1 year were excluded from analysis. We analyzed 25 liver transplants retrospectively. We prevented HBV reinfection with entecavir or tenofovir lifelong with 7 days of daily intravenous HBIG, 10,000 units, including operative day, and then once a week for the next 3 weeks, and then once a month for 1 year. Afterward, 4000 or 6000 units every 2 or 3 months were given to maintain patients' serum hepatitis B antibody titer >200 mIU/mL.

RESULTS

Mean follow-up period for HBV reinfection was 120.3 months. No patients have had reinfection.

CONCLUSIONS

Lifelong HBIG and nucleoside is an excellent prevention strategy for HBV reinfection after liver transplant.

HBV-infection rate and long-term outcome after liver-transplantation of anti-HBc-positive liver-grafts to HBV-naïve recipients: A retrospective study

BACKGROUND

Anti-HBc only positive liver grafts may be suitable for HBV-naive recipients insofar as an appropriate infection prophylaxis is performed. Therefore, we investigated the effect of prophylactic regimens on HBV infection prevention and long-term outcome of anti-HBc-positive graft recipients.

PATIENTS AND METHODS

This retrospective monocenter study consisted of a cohort of 1912 patients who underwent deceased donor liver transplantation at our transplant center between June 1987 and July 2019. 81 HBV-naïve patients after reception of an anti-HBc-positive liver-graft and consecutive HBV prophylaxis were selected for further examination. HBV infection rate and host- and graft-survival rates were compared to a matched control group consisting of 162 HBV-naïve patients after reception of anti-HBc-negative grafts. Pharmaceutical HBV prophylaxis included: only HBIG, only NUCs, or combined HBIG and NUCs.

RESULTS

Compared to control cases of HBV-naïve anti-HBc-negative graft recipients, no differences in host- and graft-survival rate were determined.13 of 81 anti-HBc-positive graft recipients (16%) developed HBV-infection after liver transplantation. No patient suffered from HBV infection after receiving modern NUCs. Survival analysis showed no statistical differences between patients with and without infection concerning host- and graft-survival.

CONCLUSION

Especially in times of organ shortage, anti-HBc-positive liver grafts may be useful for liver transplantation in HBV-naïve recipients. Efficient prophylactic regimens can prevent HBV-infection.

Significance of Hepatitis B Recurrence in Liver Transplantation Recipients

Background

A combination of antihepatitis B immunoglobulin and antiviral agents is the most common regimen for prophylaxis of hepatitis B recurrence after liver transplantation. However, hepatitis B recurrence still happens. The significance of hepatitis B recurrence is less mentioned.

Materials

Forty-eight of the 313 hepatitis B liver transplant recipients having hepatitis B recurrence were included in this study. The patients were divided into group A, the patients transplanted for hepatitis B-related liver failure, and group B, the patients transplanted for hepatitis B-related cirrhosis and HCC. The clinical manifestations after hepatitis B recurrence were recorded.

Results

Among the 48 patients with hepatitis B recurrence, 23 patients were in group A and 25 patients in group B. The age was 51.6 ± 9.4 years in group A and 52.8 ± 6.4 in group B (p = 0.869). The MELD score prior to transplantation was 23.1 ± 9.9 in group A patients and 12.9 ± 5.6 in group B patients (p < 0.001). The median (interquartile) interval from transplantation to hepatitis B recurrence was 10 (2-19) months for group A patients and 13 (8.5-35) months for group B patients (p = 0.051). After hepatitis B recurrence, the liver function was almost normal in both groups. In group B patients, 10 patients had HCC recurrence with 7 of 10 patients having hepatitis B recurrence earlier than HCC recurrence. The interval between hepatitis B and HCC recurrence was 1 to 15 months. The 1-, 3-, and 5-year survival rates were 82.6%, 73.9%, and 69.0%, respectively, for group A patients and 96%, 76%, and 68%, respectively, for group B patients (p = 0.713).

Conclusion

The patients have uneventful liver function under antiviral agent while hepatitis B recurred. For the patients having HCC prior to transplantation, close monitoring of HCC recurrence is necessary if hepatitis B recurs.

Prevention of HBV Recurrence after Liver Transplant: A Review

Globally, hepatitis B virus (HBV) infection is recognized as a major risk factor for the development of hepatocellular carcinoma, and HBV-induced liver failure is one of the leading indications for liver transplantation. Until about two decades ago, liver transplantation in patients with chronic HBV infection was a relative contraindication, due to high risk of viral replication with the use of immunosuppressants which could result in graft infection. In the 1990s, hepatitis B immunoglobulin (HBIg) use significantly reduced the risk of graft infection, improving outcomes of liver transplant in patients with chronic HBV infection. However, very high costs, especially with the need for long-term use, became a major concern. With the advent of nucleos(t)ide analogs (NAs), there was less need for high-dose, long-term HBIg use to prevent HBV recurrence. Lamivudine was initially used but resistance soon became a major issue. This was followed by more potent NAs, such as entecavir and tenofovir, emerging as the more preferred agents. Additionally, the use of these antiviral agents (HBIg and/or NAs) have made it possible to use the grafts from donors with positivity for hepatitis B core antibody, allowing for expansion of the donor pool. Nevertheless, there is no consensus on management protocols, which vary significantly amongst centers. In this review, we appraise studies on management strategies used and the role of active vaccination in the prevention of HBV recurrence in post-liver transplant patients.