Evolving experience of hepatitis B virus prophylaxis in liver transplantation

Immunoglobulin, nucleos(t)ide analogues and hepatitis B virus recurrence after liver transplant: A meta-analysis

BACKGROUND

Prophylaxis with hepatitis B immunoglobulin (HBIG) represents an efficient strategy for reducing the risk of hepatitis B virus (HBV) recurrence after liver transplantation (LT). Unfortunately, the long-term use of HBIG presents high costs. Therefore, the use of prophylaxis based only on nucleos(t)ide analogues (NUC) has been recently postulated. The present meta-analysis aimed to evaluate the impact of HBIG ± NUC vs HBIG alone or NUC alone in post-LT HBV recurrence prophylaxis.

MATERIALS AND METHODS

A systematic literature search was performed using PubMed and Cochrane databases. The primary outcome investigated was the HBV recurrence after LT. Three analyses were done comparing the effect of (a) HBIG + NUC vs HBIG alone; (b) HBIG+NUC vs NUC alone; and (c) HBIG alone vs NUC alone. Sub-analyses were also performed investigating the effect of low and high genetic barrierto-recurrence NUC.

RESULTS

Fifty-one studies were included. The summary OR (95%CI) showed a decreased risk with the combination of HBIG + NUC vs HBIG alone for HBV recurrence, being 0.36 (95% CI = 0.22-0.61; P < .001). HBIG + NUC combined treatment reduced HBV reappearance respect to NUC alone (OR = 0.22; 95% CI = 0.16-0.30; P < .0001). Similarly, HBIG alone was significantly better than NUC alone in preventing HBV recurrence (OR = 0.20; 95% CI = 0.09-0.44; P < .0001).

CONCLUSIONS

Prophylaxis with HBIG is relevant in preventing post-LT HBV recurrence. Its combination with NUC gives the best results in terms of protection. The present results should be considered in light of the fact that also old studies based on lamivudine use were included. Studies exploring in detail high genetic barrier-to-recurrence NUC and protocols with definite use of HBIG are needed.

A 6-month mixed-effect pharmacokinetic model for post-transplant intravenous anti-hepatitis B immunoglobulin prophylaxis

Background

Although individualized dosage regimens for anti-hepatitis B immunoglobulin (HBIG) therapy have been suggested, the pharmacokinetic profile and factors influencing the basis for individualization have not been sufficiently assessed. We sought to evaluate the pharmacokinetic characteristics of anti-HBIG quantitatively during the first 6 months after liver transplantation.

Methods

Identical doses of 10,000 IU HBIG were administered to adult liver transplant recipients daily during the first week, weekly thereafter until 28 postoperative days, and monthly thereafter. Blood samples were obtained at days 1, 7, 28, 84, and 168 after transplantation. Plasma HBIG titer was quantified using 4 different immunoassay methods. The titer determined by each analytical method was used for mixed-effect modeling, and the most precise results were chosen. Simulations were performed to predict the plausible immunoglobulin maintenance dose.

Results

HBIG was eliminated from the body most rapidly in the immediate post-transplant period, and the elimination rate gradually decreased thereafter. In the early post-transplant period, patients with higher DNA titer tend to have lower plasma HBIG concentrations. The maintenance doses required to attain targets in 90%, 95%, and 99% of patients were ~15.3, 18.2, and 25.1 IU, respectively, multiplied by the target trough level (in IU/L).

Conclusion

The variability (explained and unexplained) in HBIG pharmacokinetics was relatively larger in the early post-transplant period. Dose individualization based upon patient characteristics should be adjusted focusing quantitatively on the early post-transplant period.

Pharmaceutical management of hepatitis B and C in liver and kidney transplant recipients

The combination of hepatitis B immune globulin with entecavir or tenofovir (at least for a certain period of time) seems to be the most reasonable prophylaxis against recurrent hepatitis B after liver transplantation. Entecavir represents an attractive option for treatment of naïve kidney transplant recipients, because of its high efficacy and the low rates of resistance. However antiviral treatment should be individualized in the view of kidney function and the previous resistance. To date, new captivating therapeutic strategies could make interferon-free regimens viable for treatment of hepatitis C virus positive liver transplant recipients. The recent combinations of sofosbuvir with simeprevir or daclatasvir or ledipasvir plus/minus ribavirin have boosted the on treatment and sustained virological response to rates approaching 100% within liver transplant recipients with recurrent chronic hepatitis C (CHC). Preliminary data showed that the second generation direct oral antivirals could result to high treatment rates of recurrent CHC in kidney transplant recipients as well. Ongoing studies will clarify the optimal treatment of recurrent CHC in kidney transplant recipients.

Is hepatitis B immunoglobulin necessary in prophylaxis of hepatitis B recurrence after liver transplantation? A meta-analysis

Background & Aims

Application of nucleoside analogues and hepatitis B immunoglobulin (HBIG) has reduced hepatitis B virus (HBV) recurrence rate after liver transplantation (LT) dramatically. Recent data suggests therapy without HBIG is also effective. We sought to evaluate the necessity of HBIG in prophylaxis of HBV recurrence after LT.

Methods

A meta-analysis was performed. PubMed/MEDLINE, Web of Knowledge and other databases were searched for eligible literatures. The major end points were recurrence rate, patient survival, and YMDD mutant. Risk difference (RD) or risk ratio (RR) was calculated to synthesize the results.

Results

Nineteen studies with a total of 1484 patients were included in this analysis. Application of HBIG was helpful to reduce HBV recurrence [P<0.001; RD = 0.16; 95% confidence interval (CI)(0.12, 0.20)] and virus mutants [P<0.001; RR = 3.13; 95%CI (1.86–5.26)], it also improved patients' 1-year [P = 0.03; RD = 0.08; 95%CI (0.01, 0.15)] and 3-year survival rates [P = 0.005; RD = 0.17; 95%CI(0.05, 0.28)]. No significant difference was found for patients' 5-year survival [P = 0.46; RD = −0.06; 95%CI (−0.21, 0.10)]. Sub-group analysis showed that in patients with positive pre-operative HBV DNA status, HBIG was necessary to reduce HBV recurrence rate (P<0.001; RD = 0.42; 95%CI (0.32, 0.52)). In patients with negative HBV DNA, combined therapy gained no significant advantages (P = 0.18; RD = 0.06; 95%CI (−0.03, 0.14)). Non-Lamivudine (non-LAM) antiviral drugs performed as well as combination therapy in prophylaxis of HBV recurrence after LT (P = 0.37; RD = 0.06; 95%CI (−0.02, 0.14)).

Conclusions

HBIG with nucleoside analogues is helpful to reduce HBV recurrence and virus mutants. The necessity of HBIG in prophylaxis of HBV recurrence after LT when using new potent nucleoside analogues, especially for patients with negative pre-transplant HBV DNA status remains to be evaluated.

Comparison of hepatitis B prophylactic outcomes in living donor liver transplantation recipients who meet the Milan or UCSF criteria

BACKGROUND

The tumor burden before liver transplantation indicates that hepatitis B virus (HBV) may hide in the extrahepatic and micrometastatic sites which serve as a source of HBV replication. Currently, many liver transplant centers, especially in Western countries, use the Milan or UCSF criteria to select patients with hepatocellular carcinoma for liver transplantation. This study was undertaken to compare the HBV prophylactic outcomes in two groups of living donor liver transplantation (LDLT) recipients. Patients in group A met the Milan criteria and those in group B exceeded the Milan criteria but were within the UCSF criteria.

METHODS

A database of adult-to-adult right-lobe LDLT performed at our institution for HBV-related hepatocellular carcinoma within the Milan or UCSF criteria between June 2002 and May 2012 was used to compare the HBV prophylactic outcomes between patients within the Milan criteria (group A, 41 patients) and those exceeding the Milan criteria but within the UCSF criteria (group B, 19 patients).

RESULTS

The 1-, 3-, and 5-year survival rates were similar between groups A and B (87.8%, 85.1% and 74.0% vs 73.3%, 61.1% and 61.1%, respectively, P=0.067). HBV recurred in 1 patient in 3.1 months after LDLT in group A and in 2 patients in group B (1 in 11.9 months and 1 in 24.1 months after LDLT). The 1-, 3-, and 5-year HBV recurrence rates were 2.6%, 2.6% and 2.6% in group A, and 7.3%, 17.9% and 17.9% in group B, respectively (P=0.118).

CONCLUSION

LDLT recipients who exceed the Milan criteria but remain within the UCSF criteria may have post-transplant HBV prophylactic outcomes similar to those who meet the Milan criteria.

High genetic barrier nucleos(t)ide analogue(s) for prophylaxis from hepatitis B virus recurrence after liver transplantation: a systematic review

The combination of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues [NA(s)] is considered as the standard of care for prophylaxis against HBV recurrence after liver transplantation (LT), but the optimal protocol is controversial. We evaluated the efficacy of the newer NAs with high genetic barrier (hgbNA) [i.e. entecavir (ETV) or tenofovir (TDF)] with or without HBIG as prophylaxis against HBV recurrence after LT. In total, 519 HBV liver transplant recipients from 17 studies met the inclusion criteria and they were compared to those under lamivudine (LAM) and HBIG who had been selected in our previous review. Patients under HBIG and LAM developed HBV recurrence (115/1889 or 6.1%): (a) significantly more frequently compared to patients under HBIG and a hgbNA [1.0% (3/303), p < 0.001], and (b) numerically but not significantly more frequently compared to the patients who received a newer NA after discontinuation of HBIG [3.9% (4/102), p = 0.52]. The use of a hgbNA without any HBIG offered similar antiviral prophylaxis compared to HBIG and LAM combination, if the definition of HBV recurrence was based on HBV DNA detectability [0.9% vs. 3.8%, p = 0.11]. Our findings favor the use of HBIG and a hgbNA instead of HBIG and LAM combined prophylaxis against HBV recurrence after LT.

Management of Hepatitis B Virus Infection in Liver Transplantation Setting; The Rising Concerns and Growing Hopes, Report From 10th Congress of the Iranian Society for Organ Transplantation, 2011, Shiraz, Iran

Hepatitis B infection is the main cause of liver related mortality in many countries including Iran. Liver transplantation in cirrhosis due to HBV infection before 1990 was an absolute contraindication. Recurrent infection was a significant event in post liver transplant setting and resulted in increased risk of graft failure and death except successful transplanted individuals. Advances in antiviral prophylaxis have now made graft reinfection majority patients as a rare event. Graft and patient survival have been improved significantly during the past two decades, and consequences of transplantation for hepatitis B virus are now superior to those achieved for most other indications. This has encouraged many centers including the major liver transplantation center of Iran, in Shiraz, to provide liver transplantation to more patients with HBV related end stage liver disease. Management of these patients begins before transplantation along with special care after transplantation. There are some myths and doubts in the management of these patients and one should always balance the cost and efficiency. One of the major concerns is the high economic and social cost of recurrence and all possible efforts should be performed to avoid the ominous consequences of reinfection. Having a clear scientific grasp on the management of HBV cirrhosis before and after liver transplantation, options and protocols, and changing the concept which HBV infected are contraindicated ones for liver transplantation, and future hopes in increasing patients survival after liver transplantation using the new nucleosides analogues and availability of hepatitis B immunoglobulin in the transplantation setting. This scientific report paper outlines the insights communicated at the HBV and liver transplantation symposium during 10th Congress of the Iranian Society for Organ Transplantation, May 2011, Shiraz, Iran.

Hepatitis B immune globulin in liver transplantation prophylaxis: an update

CONTEXT

Liver transplantation is the best treatment option for end-stage liver disease following hepatitis B (HBV) infection. However, the high rate of recurrence of HBV infection following transplantation is a disadvantage of this option.

EVIDENCE ACQUISITION

Over the past 2 decades, the gold standard of prophylactic treatment for the prevention of HBV re-infection following liver transplantation has been the administration of low- to high-dose hepatitis B immune globulin (HBIg) along with an antiviral agent to induce passive immunity.

RESULTS

The effectiveness of HBIg in preventing the recurrence of HBV depends on the dosage, route of administration, and duration of HBIg treatment, and the viremic status at the time of transplantation. There is currently no consensus on a standardized recommendation for therapeutic options that include HBIg administration.

CONCLUSION

This review attempts to summarize the available data on the feasibility of such options. Most recent studies support the use of long-term combination therapy of HBIg and antiviral NAs (especially new agents).

Hepatitis B immunoglobulin for prevention of hepatitis B virus infection and recurrence after liver transplantation

Intravenous hepatitis B immunoglobulin (HBIG) is a human plasma-derived purified gammaglobulin (IgG) that has proven efficacy and dose-dependent response in the prevention of hepatitis B virus (HBV) recurrence after liver transplantation. It is also indicated for postexposure prophylaxis after contact with blood or body fluids of serum hepatitis B surface antigen (HBsAg)-positive carriers and in prevention of mother-to-child (vertical) transmission. The exact mechanism of passive immunization is unknown; HBIG may block HBV entry and binding to hepatocytes, neutralize circulating HBV and target HBV-infected cells through an antibody-mediated immune response. The drug is well tolerated and common side effects include fever, chills and arthralgias that are usually mild and transient. This article summarizes the main indications and the recommendations for use of intravenous HBIG, as well as the usage of intramuscular HBIG in the liver transplant setting.

A novel model for evaluating the risk of hepatitis B recurrence after liver transplantation

BACKGROUND

Hepatitis B virus (HBV) recurrence is a major risk factor affecting the long-term survival of recipients for liver transplantation (LTx). Therefore, a model that can assess this risk before transplantation is highly desirable.

METHODS

One hundred and eighty-five consecutive liver transplant recipients because of HBV-related end-stage liver diseases were selected. Their perioperative laboratory examination results, treatment protocol and the status of HBV recurrence were the primary parameters used to assess their risk of post-transplant HBV recurrence. A model that may be generally used to evaluate the risk of post-transplant HBV recurrence was thus established. A cohort for further validation and a cross-validation were designed.

RESULTS

After a follow-up time of 26.0 ± 10.8 months, the overall HBV recurrence rate was 8.6%. The 1-, 2- and 3-year cumulative survival rates were 98.5, 89.2 and 83.4% respectively. By correlation with the pretransplant presence of hepatocelluar carcinoma (HCC), serum HBV DNA level and status of antiviral treatment (AVT), the risk assessment model can be summarized using the following equation: RISK=-4.378 + 1.493 × HCC + 1.286 × DNA - 2.426 × AVT. The HBV recurrence rate and survival were found to be significantly different between the recipients with risk scores ≤-2.8 and >-2.8. The model was well validated in this work.

CONCLUSIONS

Pretransplant HBV DNA level, presence of HCC, AVT status and post-transplant viral mutation were identified as the major risk factors associated with HBV recurrence after LTx. A novel model incorporating these factors could effectively evaluate the risk of post-transplant HBV recurrence before transplantation.

Hepatitis B immunoglobulin and/or nucleos(t)ide analogues for prophylaxis against hepatitis b virus recurrence after liver transplantation: a systematic review

A combination of hepatitis B immunoglobulin (HBIG) and nucleos(t)ide analogues (NUCs) is currently recommended as prophylaxis against the recurrence of hepatitis B virus (HBV) after liver transplantation (LT), but the optimal protocol is a matter of controversy. The aim of this study was the identification of factors associated with post-LT HBV recurrence in patients receiving HBIG and NUCs. We searched MEDLINE and PubMed for studies in English about the effectiveness of HBIG and NUCs [lamivudine (LAM) and/or adefovir dipivoxil (ADV)] against post-LT HBV recurrence (January 1998 to June 2010). Forty-six studies, which included 2162 HBV LT recipients, met the selection criteria. Patients receiving HBIG and LAM experienced HBV recurrence more frequently than patients receiving HBIG and ADV with or without LAM [6.1% (115/1889) versus 2.0% (3/152), P = 0.024], although they also were more frequently treated with indefinite HBIG prophylaxis (90% versus 57%, P < 0.001). For patients receiving HBIG and LAM, a lower frequency of HBV recurrence was associated with a high HBIG dosage (≥10,000 IU/day) versus a low HBIG dosage (<10,000 IU/day) during the first week after LT [3.2% (14/440) versus 6.5% (80/1233), P = 0.016], but the HBIG protocol had no impact on HBV recurrence in patients receiving HBIG and ADV. In conclusion, in comparison with the combination of HBIG and LAM, the combination of HBIG and ADV is associated with a lower rate of HBV recurrence after LT. Patients receiving HBIG and LAM should be given a high dosage of HBIG during the first week after LT, but a lower dosage can be used safely in patients receiving HBIG and ADV. Further studies with newer and more potent anti-HBV agents are definitely required.

Lamivudine or adefovir dipivoxil alone or combined with immunoglobulin for preventing hepatitis B recurrence after liver transplantation

BACKGROUND

Recurrence of hepatitis B virus (HBV) infection in the liver graft is a grave complication following liver transplantation for HBV cirrhosis. Hepatitis B immunoglobulin (HBIg) seems effective in increasing survival after liver transplantation. HBIg and anti-viral drugs are given alone or in combination for its prevention.

OBJECTIVES

To assess the benefits and harms of different regimens for preventing HBV reactivation following liver transplantation.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2010. We attempted to identify further trials by reviewing the reference lists and contacting the principal authors of identified trials.

SELECTION CRITERIA

Randomised clinical trials addressing benefits and harms of lamivudine or adefovir dipivoxil alone or in combination with hepatitis B immunoglobulins (HBIg) for preventing recurrent HBV infection in patients who are liver transplanted due to HBV infection with or without hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the trials for risk of bias and extracted data. We contacted study authors whenever information was lacking. We collected information on adverse events. The primary outcomes were all-cause mortality and reappearance of hepatitis B surface antigen in serum after liver transplantation. Relative risks were calculated from individual trials.

MAIN RESULTS

Four trials, recruiting 136 participants, were included. Two trials compared lamivudine alone versus HBIg alone. Randomisation was performed one week after transplantation in one of the trials and after six months after transplantation in another; from transplantation until randomisation, HBIg alone was given to all patients in the two trials. A third trial compared combination treatment with lamivudine and HBIg versus lamivudine alone after one month of combination treatment, and a fourth trial compared the combination of lamivudine and HBIg versus a combination of lamivudine and adefovir dipivoxil after at least 12-month of lamivudine and HBIg combination treatment. Statistically significant differences were not detected in any of the comparisons and outcomes. All trials were open-labelled, and none of the trials were adequately powered to show a difference in HBV recurrence. No meta-analyses were performed since the identified trials assessed different comparisons.

AUTHORS' CONCLUSIONS

This review could not derive clear evidence from randomised clinical trials for the treatment of patients with chronic HBV following liver transplantation for preventing recurrence of HBV infection. Large randomised clinical trials comparing long-term combination treatment to each of the monotherapy alone, including the newer antiviral drugs, are needed.

Prevention of recurrent hepatitis B virus infection after liver transplantation: hepatitis B immunoglobulin, antiviral drugs, or both? Systematic review and meta-analysis

OBJECTIVES

To evaluate antiviral prophylaxis against hepatitis B virus (HBV) following liver transplantation.

METHODS

Systematic review and meta-analysis. Clinical trials and comparative cohort studies comparing the use of hepatitis B immunoglobulin (HBIg), antivirals, or both following liver transplantation for HBV infection were included. The primary outcome was reappearance of hepatitis B surface antigen (HBsAg). Other outcomes included all-cause and HBV-related mortality, HB-related active liver disease, and reappearance of HBV DNA after transplantation. Relative risks (RR) with 95% confidence intervals (CIs) are reported.

RESULTS

Twenty studies (22 comparisons) were included. Ten studies compared HBIg to combination treatment, 9 compared antivirals to combination treatment, and 3 compared lamivudine (LAM) to HBIg. Combination treatment reduced HBsAg reappearance (RR 0.28; 95% CI 0.12-0.66), and was superior to HBIg alone in all other outcome measures. Combination treatment was significantly better than antivirals in preventing reappearance of HBsAg (RR 0.31; 95% CI 0.22-0.44), even when low-dose HBIg was given. No significant difference was found between HBIg and LAM monotherapy for all measured outcomes. Major limitations with regard to comparability of the study groups in non-randomized trials were revealed.

CONCLUSIONS

Combination treatment with HBIg and LAM reduced HBV recurrence following liver transplantation, compared with HBIg or LAM alone, and reduced mortality compared with HBIg alone.

Current management of hepatitis B virus infection before and after liver transplantation

The progress in treatment against hepatitis B virus (HBV) has substantially improved the outcome of all HBV-infected patients. We systematically reviewed the existing data in the management of HBV transplant patients in order to assess the optimal regimen in the pretransplant setting, for post-transplant prophylaxis and for therapy of HBV recurrent infection. All data suggest that an effective pretransplant anti-HBV therapy prevents post-transplant HBV recurrence. Pretransplant therapy has been based on lamivudine with addition of adefovir upon lamivudine resistance, but the use of newer, potent high-genetic barrier agents is expected to improve long-term efficacy. Moreover, it may lead to improvement of liver function, which sometimes removes the need for transplantation, although more objective criteria for removal from waiting lists are required. After liver transplantation, the combination of HBV immunoglobulin and one nucleos(t)ide analogue, mostly lamivudine, is currently the best approach, almost eliminating the probability of HBV recurrence. Treatment of post-transplant HBV recurrence has been mainly studied with lamivudine, but it will be most effective with entecavir and tenofovir, which have a low risk of resistance. In conclusion, the newer anti-HBV agents improve the treatment of HBV both pretransplant and post-transplant. HBV immunoglobulin is still used in combination with an anti-HBV agent for post-transplant prophylaxis. Monoprophylaxis with one of the new anti-HBV agents might be possible, particularly in patients preselected as having a low risk of HBV recurrence, but further data are needed and strategies to ensure compliance must be used.

Hepatitis B immunoglobulin in preventing reinfection following liver transplantation

Before the availability of hepatitis B immunoglobulin (HBIG) in hepatitis B-positive transplant recipients, the acute mortality was very high, in many centers up to 50% within 60 days post-transplant. The overall reinfection rate was approximately 60% within the initial 6 months, increasing to 80-90% within the initial 12 months and, in many cases, leading to allograft loss and death or retransplantation. These recurrent infections were often more severe and more rapidly progressing than the initial infection, probably due to high-dose immunosuppressive regimens. The poor prognosis before introduction of HBIG made hepatitis B liver disease an absolute contraindication for liver transplantation, leaving these patients with very limited treatment options. This changed in the late 1980s with the introduction of HBIG, which reduced the incidence of hepatitis B in the transplanted liver to approximately 15-50%, with concomitant improvement in graft and overall survival. The prognosis was further improved by a combination of long-term HBIG and antiviral therapy, in particular lamivudine, which reduced the reinfection rate, in most cases to between 0 and 5%. Owing to the cost and relative inconvenience of HBIG, some transplant centers have experimented with early discontinuation of HBIG and replacement with antiviral monotherapy. A number of studies, however, have found significantly higher recurrence rates associated with lamivudine monotherapy (40-50%) compared with combination therapy and, hence, lamivudine monotherapy is not recommended.

Hepatitis B immunoglobulin and Lamivudine improve hepatitis B-related outcomes after liver transplantation: meta-analysis

BACKGROUND & AIMS

HBV recurrence increases morbidity and mortality in HBsAg+ patients undergoing liver transplantation. We aimed to estimate the relative efficacy of combined therapy with hepatitis B immunoglobulin (HBIG) and lamivudine (LAM) versus HBIG monotherapy for preventing HBV-related morbidity and mortality in this setting.

METHODS

We performed a meta-analysis of clinical trials that met the prespecified criteria and provided data for risk estimation of HBV recurrence in HBsAg+ liver transplant patients receiving HBIG and LAM versus HBIG alone. Databases searched until May 2007 included MEDLINE (Ovid), PubMed, Embase, Toxnet, Scopus, and Web of Science. Literature search and data extraction were conducted independently by 2 study investigators; then 2 other investigators reviewed and screened eligible studies. Odds ratios (ORs) for the risk reduction with HBIG and LAM versus HBIG alone were calculated by using a random-effects model.

RESULTS

Two prospective and 4 retrospective studies were included in the meta-analysis. The OR showing risk reduction in HBV recurrence with HBIG and LAM (n = 193) versus HBIG alone (n = 124) was 0.08 (95% confidence interval [CI], 0.03-0.21). HBV-related death and all-cause mortality could only be assessed in 3 studies each. The ORs showing HBV-related death and all-cause mortality reduction with HBIG and LAM versus HBIG alone were 0.08 (95% CI, 0.02-0.33) and 0.02 (95% CI, 0.06-0.82), respectively.

CONCLUSIONS

Although this meta-analysis was limited by small studies and varying levels of immunosuppression, it is apparent that adding LAM to HBIG improved HBV-related morbidity and mortality in HBsAg+ recipients of liver transplants.

[The prophylaxis against post-liver-transplant hepatitis B re-infection]

OBJECTIVE

To review the prophylaxis against post-liver transplantation hepatitis B reinfection with anti-hepatitis B immunoglobulin and nucleoside analogues.

METHOD

A bibliographic search was carried out using Pubmed, entering the following key words: hepatitis B and liver transplantation and (hepatitis B hyperimmune globulin and lamivudine and adefovir dipivoxil) up to June 2006. The initial search was filtered using the terms clinical trial, randomized clinical trial and review. The data contained in selected studies were reviewed.

RESULTS

A total of 53 works were found. Prophylaxis with anti-HB immunoglobulin and lamivudine is the best strategy for avoiding recurrence of the hepatitis B virus in patients undergoing hepatic transplants; achieving very low reinfection rates (0-10%) with follow up periods of between 1-5 years. There is a great degree of variability (dose, duration and method of HBIg administration) in the prophylactic protocols reviewed. The use of low doses of anti-HB immunoglobulin (administered intravenously followed by intramuscular administration, or administered intramuscularly from the anhepatic stage), and lamivudine in patients who receive transplants with a low risk of recurrence, shows prophylactic efficacy comparable to the use of high doses of anti-HB immunoglobulin. Furthermore, it implies a considerable reduction in costs.

CONCLUSIONS

The availability of suitably designed clinical trials is required to design a more cost-effective protocol and reduce variability.

Monoclonal antibody HCV-AbXTL68 in patients undergoing liver transplantation for HCV: results of a phase 2 randomized study

A randomized, double-blind, dose-escalation study evaluated the safety and efficacy of hepatitis C virus (HCV)-Ab(XTL)68, a neutralizing, high-affinity, fully human, anti-E2 monoclonal antibody, in 24 HCV-positive patients undergoing liver transplantation. HCV-Ab(XTL)68 or placebo was administered at doses from 20-240 mg as 2-4 infusions during the first 24 hours after transplantation, followed by daily infusions for 6 days, weekly infusions for 3 weeks, and either 2 or 4 weekly infusions for 8 weeks. Serum concentrations of total anti-E2 obtained during daily infusions of 120-240 mg HCV-Ab(XTL)68 were 50-200 microg/mL above concentrations in the placebo group. Median serum concentration of HCV RNA dropped below baseline in all groups immediately after transplantation. On day 2, median change from baseline in HCV RNA was -1.8 and -2.4 log in the 120-mg and 240-mg groups, respectively, compared with -1.5 log with placebo. The difference was lost after day 7 when the dosing frequency was reduced. The coincidence of increases in anti-E2 with decreases in HCV RNA concentration indicate that the dose-related changes in HCV RNA concentration were a result of HCV-Ab(XTL)68 administration in the 120- and 240-mg groups. The overall incidence of nonfatal serious adverse events was higher with placebo (60%) vs. all active treatments combined (42%). In conclusion, HCV-Ab(XTL)68 may decrease serum concentrations of HCV RNA in patients after liver transplantation. Studies evaluating more frequent daily dosing at doses >120 mg are necessary to investigate sustained viral suppression in this population.

Prevention of de novo HBV infection by the presence of anti-HBs in transplanted patients receiving core antibody-positive livers

AIM: To analyze whether the presence of anti-HBs in liver transplant recipients is effective in preventing HBV infection.

METHODS: Twenty-three patients receiving anti-HBc positive liver were studied. Nine recipients were anti-HBc positive as a result of previous HBV infection. Of them, one also received HBV vaccine during the pre-liver transplantation period. Fourteen recipients were anti-HBs positive due to HBV vaccine administered during the pre-transplant period. Liver biopsy was obtained in 10/14 anti-HBc negative/anti-HBs positive recipients and in 4/9 anti-HBc positive recipients.

RESULTS: After a mean follow-up period of 46 months, 1 recipient with protective serum anti-HBs levels developed de novo HBV infection as a consequence of immune escape HBV mutants. Among the 14 vaccinated anti-HBc negative/anti-HBs positive recipients, 1/10 patients with available liver biopsy (10%) had liver HBV-DNA at 13 mo post-liver transplantation without serum viral markers and did not develop de novo HBV infection. The vaccinated anti-HBc positive recipient without HBV vaccine response was HBV-DNA positive in serum and liver, viral DNA was continuously negative in the following tests, so a spontaneous seroconversion was diagnosed.

CONCLUSION: The presence of anti-HBs as a result of HBV vaccine or past HBV infection seems to be effective at protecting patients receiving livers from anti-HBc positive donors. However, the emergence of immune escape HBV mutants, which can evade the anti-HBs protection, should be considered as a risk of HBV infection.

Prevention of hepatitis B virus reinfection after orthotopic liver transplantation

OBJECTIVE

We discuss the prevention of hepatitis B virus reinfection following orthotopic liver transplantation.

METHODS

Sixty-eight cases of chronic fulminant hepatitis B, the end stage of liver cirrhosis and liver carcinoma complicated with HBV cirrhosis, were given antiviral drugs pre- and posttransplantation to prevent hepatitis B virus reinfection. Lamivudine was administered to two cases and lamivudine + HBIG to 63 cases. Adefovir + HBIG was administered to three cases. The serum HBV, HBV DNA, liver biopsy immunohistochemistry and clinical examinations were performed.

RESULTS

One of two cases given lamivudine developed reinfection with serum HBSAg, HbeAb, HBcAb, HBV DNA, and positive and liver biopsy immunohistochemistry showing HBSAg phenotype. Two of the 63 cases given lamivudine + HBIG developed reinfection with serum HBSAg, HBeAb, HBcAb positive and liver biopsy immunohistochemistry showing HBSAg phenotype. The serum HBV DNA was positive in one of the two cases. Three cases given adefovir developed no reinfection with HBV.

CONCLUSION

Orthotopic liver transplantation is an effective treatment for HBV infection; lamivudine + HBIG or adefovir + HBIG prevent hepatitis B virus reinfection.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

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Use of combined treatment of hepatitis B immune globulin and lamivudine as prevention of hepatitis B virus recurrence in liver allograft

Antiviral prophylaxis with lamivudine appears to reduce hepatitis B virus (HBV) infection after liver transplantation, although recurrence of infection occurs in at least 20% of the patients because of the development of drug resistance. Treatment for HBV reinfection with lamivudine pretransplantation and posttransplantation together with hepatitis B immunoglobulin could abolish recurrence of HBV infections following liver transplantation. We report the experience at our center in which lamivudine has been used in combination with low doses of immunoglobulin. Lamivudine (100 mg/d) was administered to liver transplant candidates for at least 4 weeks before transplantation and was continued posttransplantation indefinitely. Immunoglobulin was administered intramuscularly (10,000 IU at time of liver transplantation; 1,000 IU for 1 week; 1,000 IU weekly the first month; and 1,000 IU monthly thereafter). Lamivudine and low-dose immunoglobulin administration prevents posttransplantation recurrence of hepatitis B with 100% efficiency; it is well tolerated and is less cost-effective than high-dose immunoglobulin regimens.