Selection of mutations in the hepatitis B virus polymerase during therapy of transplant recipients with lamivudine

We describe mutations in the hepatitis B virus (HBV) polymerase gene in viruses which reactivated in two patients during therapy with -2'-deoxy-3'-thiacytidine, or lamivudine (3TC), and following orthotopic liver transplantation for chronic hepatitis B. Virus resistance to 3TC is associated with mutations which lead to amino acid substitutions in the highly conserved tyr-met-asp-asp (YMDD) motif, part of the active site of the polymerase, and which parallel those seen in resistant human immunodeficiency virus (HIV). Substitutions of valine and isoleucine for methionine were found in the two cases. The significance of single secondary mutations, which differ between viruses from the two patients, remains to be determined. Thus, viral resistance to lamivudine of hepatitis B virus mimics that of HIV and can occur in the setting of immunosuppression after liver transplantations.

Ledipasvir and sofosbuvir plus ribavirin in patients with genotype 1 or 4 hepatitis C virus infection and advanced liver disease: a multicentre, open-label, randomised, phase 2 trial

BACKGROUND

Treatment options are limited for patients infected by hepatitis C virus (HCV) with advanced liver disease. We assessed the safety and efficacy of ledipasvir, sofosbuvir, and ribavirin in patients with HCV genotype 1 or 4 and advanced liver disease.

METHODS

We did an open-label study at 34 sites in Europe, Canada, Australia, and New Zealand. Cohort A included patients with Child-Turcotte-Pugh class B (CTP-B) or CTP-C cirrhosis who had not undergone liver transplantation. Cohort B included post-transplantation patients who had either no cirrhosis; CTP-A, CTP-B, or CTP-C cirrhosis; or fibrosing cholestatic hepatitis. Patients in each group were randomly assigned (1:1) using a computer-generated randomisation sequence to receive 12 or 24 weeks of ledipasvir (90 mg) and sofosbuvir (400 mg) once daily (combination tablet), plus ribavirin (600-1200 mg daily). The primary endpoint was the proportion of patients achieving a sustained virological response 12 weeks after treatment (SVR12). All patients who received at least one dose of study drug were included in the safety analysis and all patients who received at least one dose of study drug and did not undergo liver transplantation during treatment were included in the efficacy analyses. Estimates of SVR12 and relapse rates and their two-sided 90% CI (Clopper-Pearson method) were provided. This exploratory phase 2 study was not powered for formal comparisons among treatment groups; no statistical hypothesis testing was planned or conducted. The trial is registered with EudraCT (number 2013-002802-30) and ClinicalTrials.gov (number NCT02010255).

FINDINGS

Between Jan 14, 2014, and Aug 19, 2014, 398 patients were screened. Of 333 patients who received treatment, 296 had genotype 1 HCV and 37 had genotype 4 HCV. In cohort A, among patients with genotype 1 HCV, SVR12 was achieved by 20 (87%, 90% CI 70-96) of 23 CTP-B patients with 12 weeks of treatment; 22 (96%, 81-100) of 23 CTP-B patients with 24 weeks of treatment; 17 (85%, 66-96) of 20 CTP-C patients (12 weeks treatment); and 18 (78%, 60-91) of 23 CTP-C patients (24 weeks treatment). In cohort B, among patients with genotype 1 HCV, SVR12 was achieved by 42 (93%, 84-98) of 45 patients without cirrhosis (12 weeks treatment); 44 (100%, 93-100) of 44 patients without cirrhosis (24 weeks treatment); 30 (100%, 91-100) of 30 CTP-A patients (12 weeks treatment); 27 (96%, 84-100) of 28 CTP-A patients (24 weeks treatment); 19 (95%, 78-100) of 20 CTP-B patients (12 weeks treatment); 20 (100%, 86-100) of 20 CTP-B patients (24 weeks treatment); one (50%, 3-98) of two CTP-C patients (12 weeks treatment); and four (80%, 34-99) of five CTP-C patients (24 weeks treatment). All five patients with fibrosing cholestatic hepatitis achieved SVR12 (100%, 90% CI 55-100). Among all patients with genotype 4 HCV, SVR12 was achieved by 14 (78%, 56-92) of 18 patients (12 weeks treatment) and 16 (94%, 75-100) of 17 patients (24 weeks treatment). Seven patients (2%) discontinued ledipasvir-sofosbuvir prematurely due to adverse events. 17 patients died, mainly from complications of hepatic decompensation.

INTERPRETATION

Ledipasvir-sofosbuvir and ribavirin provided high rates of SVR12 for patients with advanced liver disease, including those with decompensated cirrhosis before or after liver transplantation.

FUNDING

Gilead Sciences.

Adefovir dipivoxil added to ongoing lamivudine in chronic hepatitis B with YMDD mutant hepatitis B virus

BACKGROUND AND AIMS

Prolonged lamivudine therapy is associated with treatment-resistant YMDD mutant hepatitis B virus (HBV). We evaluated the efficacy and safety of adding adefovir dipivoxil to lamivudine in 135 patients with chronic hepatitis B (CHB) and YMDD mutant HBV.

METHODS

Ninety-five patients with compensated CHB (group A) were randomized to adefovir 10 mg daily (n = 46) or placebo (n = 49) for 52 weeks while continuing treatment with lamivudine. Forty patients with decompensated hepatitis B or post-liver transplantation (group B) received adefovir and lamivudine. The primary end point was a decline in serum HBV DNA level to 10(5) copies/mL or a >2 log(10) reduction from baseline at weeks 48 and 52.

RESULTS

HBV DNA response occurred in 85% of patients (39 of 46) in group A given combined therapy versus 11% (5 of 46) receiving lamivudine alone (P < 0.001), with a significant change in HBV DNA level from baseline (P < 0.001) between treatment groups (median, -4.6 vs. +0.3 log(10) copies/mL, respectively). Normalization of alanine aminotransferase levels occurred in 31% of patients (14 of 45) receiving combined therapy versus 6% (3 of 48) receiving lamivudine alone (P = 0.002). Ninety-two percent of patients (36 of 39) in group B had an HBV DNA response (median change of -4.6 log(10) copies/mL) and improved liver chemistries (P < or = 0.001). Both treatment regimens were well tolerated, and renal function abnormalities were not observed in either group.

CONCLUSIONS

The addition of adefovir dipivoxil to lamivudine in patients with CHB with compensated or decompensated liver disease due to YMDD mutant HBV is associated with virologic and biochemical improvement during 52 weeks of treatment and is well tolerated.

Lamivudine prophylaxis against reinfection in liver transplantation for hepatitis B cirrhosis

BACKGROUND

Orthotopic liver transplantation in patients positive for hepatitis B virus (HBV) DNA is associated with a high reinfection rate, even with hepatitis B immunoglobulin (HBIG) prophylaxis. Nucleoside analogues that inhibit hepatitis B replication in patients with chronic hepatitis B could prevent reinfection after transplantation. The aim of this study was to analyse the efficacy and safety of prophylaxis both before and after transplantation with the nucleoside analogue lamivudine, without HBIG, in patients undergoing liver transplantation.

METHODS

17 HBsAg-positive patients with decompensated cirrhosis and previous evidence of viral replication were enrolled. 12 were HBV-DNA-positive by a signal amplification assay. Patients were treated with oral lamivudine (100 mg daily) for at least 4 weeks before transplantation and followed up for 18-90 weeks after transplantation.

FINDINGS

HBV DNA became undetectable in serum before transplantation in all HBV-DNA-positive patients. Four died before transplantation from complications of cirrhosis; one patient was withdrawn from the study because of a cerebrovascular accident. The remaining 12 patients underwent transplantation. Two patients died after transplantation (one at 3 days and one [suicide] at 20 weeks). HBV DNA reappeared in one patient with histological evidence of recurrent hepatitis (72 weeks). By week 24 the nine remaining patients had lost HBsAg and remained negative for HBV DNA.

INTERPRETATION

Lamivudine treatment may prove useful in preventing recurrence of hepatitis B after liver transplantation. The effect on survival of patients after transplantation remains to be assessed.

Enhanced liver fibrosis test can predict clinical outcomes in patients with chronic liver disease

BACKGROUND

Clinicians use fibrosis in a liver biopsy to predict clinical outcomes of chronic liver disease. The performance of non-invasive tests has been evaluated against histological assessment of fibrosis but use of clinical outcomes as the reference standard would be ideal. The enhanced liver fibrosis (ELF) test was derived and validated in a large cohort of patients and shown to have high diagnostic accuracy (area under the curve (AUC)=0.80 95% CI 0.76 to 0.85) in identification of significant fibrosis on biopsy.

OBJECTIVE

To evaluate ELF performance in predicting clinical outcomes by following up the original ELF cohort.

METHODS

Patients recruited to the ELF study at seven English centres were followed up for liver morbidity and mortality by examination of clinical data. Defaulting/discharged patients were followed up by family practitioner questionnaires. Primary outcome measure was liver-related morbidity/liver-related death.

RESULTS

457 patients were followed up (median 7 years), with ascertainment of clinical status in 92%. There were 61 liver-related outcomes (39 deaths). Survival analysis showed that the ELF score predicts liver outcomes, with people having the highest ELF scores being significantly more likely to have clinical outcomes than those in lower-score groups. A Cox proportional hazards model showed fully adjusted HRs of 75 (ELF score 12.52-16.67), 20 (10.426-12.51) and 5 (8.34-10.425) compared with patients with ELF <8.34. A unit change in ELF is associated with a doubling of risk of liver-related outcome.

CONCLUSIONS

An ELF test can predict clinical outcomes in patients with chronic liver disease and may be a useful prognostic tool in clinical practice.

Advancing donor liver age and rapid fibrosis progression following transplantation for hepatitis C

BACKGROUND AND AIM

Cirrhosis with liver failure due to hepatitis C virus (HCV) infection is the most common indication for liver transplantation (LT). Reinfection of the transplanted liver by HCV is inevitable, and aggressive hepatitis with accelerated progression to graft cirrhosis may be observed. Of concern, recent reports suggest that the outcome of LT for HCV may have deteriorated in recent years. Determinants of rate of progression to cirrhosis in the immunocompetent non-transplant patient are well defined, and the most powerful determinant is patient age at the time of infection. Following LT for HCV, recipient age does not affect outcome of HCV reinfection. However, the impact of donor age on graft fibrosis progression rate following LT has not been examined.

METHODS

We have examined post-transplant biopsies to assess histological activity, including fibrosis stage (scored 0-6 units, 6 representing established cirrhosis), and to calculate fibrosis progression rates in 101 post-transplant specimens from 56 HCV infected LT patients. Univariate and multivariate analyses examined the impact of parameters including recipient and donor age and sex on fibrosis progression rate, and on predicted time to cirrhosis.

RESULTS

For the cohort, median fibrosis progression rate was 0.78 units/year, and median interval from transplantation to development of cirrhosis was 7.7 years. In multivariate analysis, donor age (not recipient age) was a powerful determinant (p=0.02) of fibrosis progression rate. When the liver donor was younger than 40 years, median progression rate was 0.6 units/year and interval to cirrhosis was 10 years. When the donor was aged 50 years or more, median progression rate was 2.7 units/year and interval to cirrhosis only 2.2 years. During the observation period there has been a significant increase in donor age (p=0.01) but date of transplantation per se is not a determinant of progression rate when included in multivariate analyses.

CONCLUSIONS

Donor age has a major influence on graft outcome following transplantation for HCV. The changing organ donor profile will affect the long term results of LT for HCV. These observations have important implications for donor liver allocation.

Entecavir treatment does not eliminate the risk of hepatocellular carcinoma in chronic hepatitis B: limited role for risk scores in Caucasians

BACKGROUND

Hepatocellular carcinoma (HCC) risk-scores may predict HCC in Asian entecavir (ETV)-treated patients. We aimed to study risk factors and performance of risk scores during ETV treatment in an ethnically diverse Western population.

METHODS

We studied all HBV monoinfected patients treated with ETV from 11 European referral centres within the VIRGIL Network.

RESULTS

A total of 744 patients were included; 42% Caucasian, 29% Asian, 19% other, 10% unknown. At baseline, 164 patients (22%) had cirrhosis. During a median follow-up of 167 (IQR 82-212) weeks, 14 patients developed HCC of whom nine (64%) had cirrhosis at baseline. The 5-year cumulative incidence rate of HCC was 2.1% for non-cirrhotic and 10.9% for cirrhotic patients (p<0.001). HCC incidence was higher in older patients (p<0.001) and patients with lower baseline platelet counts (p=0.02). Twelve patients who developed HCC achieved virologic response (HBV DNA <80 IU/mL) before HCC. At baseline, higher CU-HCC and GAG-HCC, but not REACH-B scores were associated with development of HCC. Discriminatory performance of HCC risk scores was low, with sensitivity ranging from 18% to 73%, and c-statistics from 0.71 to 0.85. Performance was further reduced in Caucasians with c-statistics from 0.54 to 0.74. Predicted risk of HCC based on risk-scores declined during ETV therapy (all p<0.001), but predictive performances after 1 year were comparable to those at baseline.

CONCLUSIONS

Cumulative incidence of HCC is low in patients treated with ETV, but ETV does not eliminate the risk of HCC. Discriminatory performance of HCC risk scores was limited, particularly in Caucasians, at baseline and during therapy.

Entecavir treatment for chronic hepatitis B: adaptation is not needed for the majority of naïve patients with a partial virological response

Entecavir (ETV) is a potent inhibitor of viral replication in nucleos(t)ide analogue (NA)-naïve chronic hepatitis B (CHB) patients. The aim of this study was to investigate the long term efficacy and safety of ETV in NA-naïve CHB patients, particularly in those with detectable hepatitis B virus (HBV) DNA after 48 weeks, in whom treatment adaptation is suggested by current guidelines. In a multicenter cohort study, we investigated 333 CHB patients treated with entecavir monotherapy. The NA-naïve population consisted of 243 patients, whereas 90 were NA-experienced. Virological response (VR) (HBV DNA<80 IU/mL) was achieved in 48%, 76%, and 90% of hepatitis B e antigen (HBeAg)-positive and in 89%, 98%, and 99% of HBeAg-negative NA-naïve patients at weeks 48, 96, and 144, respectively. Thirty-six of 175 (21%) NA-naïve patients with at least 48 weeks of follow-up had a detectable load at week 48 (partial virological response [PVR]). Twenty-nine (81%) patients with PVR reached VR during prolonged ETV monotherapy, and none of them developed ETV-resistance. Among 22 patients with HBV DNA<1,000 IU/mL at week 48, VR was achieved in 21 (95%) patients, compared with eight of 14 (57%) patients with HBV DNA≥1,000 IU/mL. Continuous HBV DNA decline was observed in most patients without VR during follow-up, and in three patients adherence was suboptimal according to the treating physician. ETV was safe and did not affect renal function or cause lactic acidosis.

CONCLUSION

ETV monotherapy can be continued in NA-naïve patients with detectable HBV DNA at week 48, particularly in those with a low viral load because long-term ETV leads to a virological response in the vast majority of patients.

Glecaprevir/Pibrentasvir Treatment in Liver or Kidney Transplant Patients With Hepatitis C Virus Infection

Well-tolerated, ribavirin-free, pangenotypic hepatitis C virus (HCV) treatments for transplant recipients remain a high priority. Once-daily glecaprevir/pibrentasvir demonstrates high rates of sustained virologic response at 12 weeks posttreatment (SVR12) across all major HCV genotypes (GTs). This trial evaluated the safety and efficacy of glecaprevir/pibrentasvir for patients with chronic HCV GT1-6 infection who had received a liver or kidney transplant. MAGELLAN-2 was a phase 3, open-label trial conducted in patients who were ≥3 months posttransplant. Patients without cirrhosis who were HCV treatment-naive (GT1-6) or treatment-experienced (GT1, 2, 4-6; with interferon-based therapy with or without sofosbuvir, or sofosbuvir plus ribavirin) received glecaprevir/pibrentasvir (300/120 mg) once daily for 12 weeks. The primary endpoint compared the percentage of patients receiving glecaprevir/pibrentasvir with SVR12 to a historic SVR12 rate based on the standard of care. Safety of glecaprevir/pibrentasvir was assessed. In total, 80 liver transplant and 20 kidney transplant patients participated in the trial. Most patients had no or minimal fibrosis (80% had fibrosis scores F0-F1) and were infected with HCV GT1 (57%) or GT3 (24%). The overall SVR12 was 98% (n/N = 98/100; 95% confidence interval, 95.3%-100%), which exceeded the prespecified historic standard-of-care SVR12 threshold of 94%. One patient experienced virologic failure. One patient discontinued because of an adverse event considered to be unrelated to treatment; this patient achieved SVR12. Adverse events were mostly mild in severity, and laboratory abnormalities were infrequent.

CONCLUSION

Once-daily glecaprevir/pibrentasvir for 12 weeks is a well-tolerated and efficacious, ribavirin-free treatment for patients with chronic HCV GT1-6 infection who have received a liver or kidney transplant. (ClinicalTrials.gov NCT02692703.) (Hepatology 2018; 00:000-000).

Lamivudine without HBIg for prevention of graft reinfection by hepatitis B: long-term follow-up

BACKGROUND

This open, multicenter study was conducted to evaluate the efficacy and safety of lamivudine prophylaxis given to chronic hepatitis B virus-(HBV) infected patients before and after orthotopic liver transplantation (OLT). We now present long-term data that follow our previous short-term report.

METHODS

Twenty-three patients were treated with lamivudine (100 mg orally, daily); 13 (57%), were serum HBV DNA positive (Abbott Genostics, Abbott Laboratories, Chicago, IL) at study entry. Patients received lamivudine for at least 4 weeks before OLT, and for up to 50 months (median 25 months) after OLT.

RESULTS

Of the 23 treated patients, 17 survived to undergo OLT. Eleven patients (65%) survived up to 4 years (median 36 months) after OLT. One of the survivors stopped lamivudine because of a possible adverse reaction 9 months post-OLT, and prophylaxis with HBV immune globulin was then established. Ten survivors continue lamivudine. Eight long-term survivors have normal liver function without evidence of HBV reinfection. Of the 17 transplanted patients, 6 died. Four patients died (3 days to 5 months post-OLT) without evidence of graft reinfection. Two further patients died at 19 and 23 months post-OLT from graft failure. Both patients had YMDD variant detected at 12 months post-OLT. Two other patients with YMDD-variant HBV remain alive on lamivudine, 9 and 15 months after development of the variant.

CONCLUSIONS

Lamivudine, given before and after OLT, prevents significant graft reinfection for the majority of treated patients. The study has also shown that lamivudine is extremely well tolerated by liver failure patients and for a prolonged period after transplantation.

Outcome of lamivudine resistant hepatitis B virus infection in the liver transplant recipient

BACKGROUND

In many transplant centres lamivudine is an important component of prophylaxis against, and treatment of, hepatitis B virus (HBV) graft infection. Drug resistant HBV species with specific polymerase mutations may emerge during lamivudine treatment.

AIMS

To examine the clinical consequences of graft infection by lamivudine resistant virus.

METHODS

The clinical course of four liver transplant patients who developed graft infection with lamivudine resistant virus was reviewed. The response of HBV infection to reduction of immunosuppression and to manipulation of antiviral therapy was assessed. For each patient, serum viral titre was measured and the viral polymerase gene was sequenced at multiple time points.

RESULTS

High serum titres were observed following emergence of the lamivudine resistant species. Wild type HBV re-emerged as the dominant serum species after lamivudine withdrawal. All patients developed liver failure, and onset of liver dysfunction was observed when resistant virus was the dominant serum species. In three patients, liver recovery was observed when immunosuppression was stopped and when alternative antivirals were given. Wild type virus appeared to respond to ganciclovir, and to reintroduction of lamivudine. For one patient, introduction of famciclovir was associated with clinical, virological, and histological response.

CONCLUSIONS

Failure of lamivudine prophylaxis may identify patients at special risk for the development of severe graft infection. Treatment of graft reinfection should include reduction of immunosuppression, and systematic exposure to alternative antivirals. Viral quantitation and genetic sequencing are essential components of therapeutic monitoring.

High pre-treatment serum hepatitis B virus titre predicts failure of lamivudine prophylaxis and graft re-infection after liver transplantation

BACKGROUND/AIMS

Orthotopic liver transplantation has an established role for the treatment of patients with chronic liver failure secondary to hepatitis B virus (HBV) infection. Unfortunately, recurrent infection of the graft can be associated with aggressive disease, and with diminished graft and patient survival. Currently, the role of nucleoside analogues for prevention of graft re-infection is being evaluated. Preliminary results are encouraging, but treatment failure has been associated with emergence of drug-resistant virus.

METHODS

We have studied ten consecutive patients who received lamivudine prophylaxis for prevention of HBV graft reinfection. Sequential sera, collected prelamivudine then during treatment before and after liver transplantation, were examined. Conventional serological markers were measured, as were serum viral DNA levels with a sensitive quantitative polymerase chain reaction assay.

RESULTS

Lamivudine treatment effected a reduction in serum HBV levels, but six patients still had measurable viral DNA at the time of transplantation. Five patients developed graft re-infection with lamivudine-resistant virus. Resistant virus emerged 8 to 15 months post-transplant. The likelihood of emergence of resistant virus was related to the pre-treatment serum HBV titre. Persistent serum viral DNA positivity and evidence of graft re-infection during the early post-transplant period did not predict the subsequent emergence of resistant virus.

CONCLUSIONS

Our observations suggest that the resistant species may be present in the viral quasispecies in the serum and liver of patients with high-level replication prior to lamivudine exposure. The resistant species can persist during lamivudine treatment prior to transplantation, and emerge following transplantation. These observations suggest strategies which might prevent the emergence of drug-resistant species, and imply that graft re-infection may be a preventable phenomenon.

Combination alpha-interferon and lamivudine therapy for alpha-interferon-resistant chronic hepatitis B infection: results of a pilot study

BACKGROUND/AIMS

Alpha-interferon achieves seroconversion in about one third of naive patients. Attempts to achieve seroconversion in patients who have previously failed alpha-interferon have proved disappointing. Combination chemotherapy (alpha-interferon with a nucleoside analogue) might provide a treatment alternative for these patients. We have undertaken a phase 2 study in 20 patients who had previously failed at least one course of alpha-interferon. The study was designed to assess the safety, tolerability and efficacy of the combination.

METHODS

All patients were treated for 16 weeks with alpha-interferon in combination with 12 or 16 weeks of Lamivudine (3'TC). Patients were followed for 16 weeks post-treatment. Pharmacokinetic studies were performed to identify/exclude significant pharmacokinetic drug interaction.

RESULTS

The combination was well tolerated, and side-effects of the combination were indistinguishable from the recognised side-effects of alpha-interferon. Pharmacokinetic studies performed on days 1 and 29 did not show any significant interaction. All patients achieved HBV DNA clearance during treatment, but 19 relapsed at the end of treatment. HBeAg/anti-HBe seroconversion was observed for four patients, but was sustained for a single patient (who also had sustained DNA clearance).

CONCLUSIONS

Combination therapy with alpha-interferon and lamivudine given for 16 weeks appears safe and is well tolerated. However, for this group of patients who had previously failed interferon monotherapy, the efficacy of combination interferon/lamivudine therapy appears disappointing, and other treatment strategies should be investigated.

Outcome of liver transplantation for patients with pulmonary hypertension

It is generally believed that pulmonary hypertension (PHT) adversely affects outcome after liver transplantation (LT). Most transplant units consider severe PHT to be an absolute contraindication to LT. We examined the outcome of 145 patients who underwent LT between 1997 and 1999. Pulmonary artery pressures (PAPs) had been measured before surgery. Pre-LT workup included electrocardiography and echocardiography for the majority of patients. Also, the liver unit database was screened for patients with known PHT who had undergone LT before 1997. Based on pulmonary flotation catheter measurements made after the induction of anesthesia for LT, PHT was defined as mild or moderate to severe if the mean PAP (MPAP) exceeded 25 and 35 mm Hg, respectively. The incidence of PHT was 26% (38 of 145 patients); 31 of 38 patients had mild PHT. Kaplan-Meier survival analysis did not show a significant survival benefit for patients with normal PAPs compared with patients with PHT (all, mild, moderate to severe). For surviving patients, the duration of ventilation and intensive care unit stay was unaffected by PHT. Four of 5 patients (identified from the database 1982 to 1999) with MPAPs greater than 40 mm Hg survived LT by more than 1 year. PHT of this severity was usually associated with specific and suggestive abnormality of the echocardiogram. Mild PHT is common and does not affect patient outcome after LT. Moderate and severe PHT are uncommon. Our analysis suggests that when the cardiac index is preserved, the majority of patients with moderate and severe PHT can survive LT, and they will not die of PHT during long-term follow-up. Echocardiography detects most severe PHT, but not mild and moderate PHT.

Hepatitis C virus association with peripheral blood B lymphocytes potentiates viral infection of liver-derived hepatoma cells

Hepatitis C virus (HCV) primarily replicates within the liver, leading to hepatitis, fibrosis, and hepatocellular carcinoma. Infection is also associated with B-cell abnormalities, suggesting an association of the virus with B cells. The infectious JFH-1 strain of HCV can bind primary and immortalized B cells but fails to establish productive infection. However, B cell-associated virus readily infects hepatoma cells, showing an enhanced infectivity compared with extracellular virus. B cells express the viral receptors CD81, SR-BI, and the C-type lectins DC-SIGN and L-SIGN. Antibodies specific for SR-BI and DC-SIGN/L-SIGN reduced B-cell transinfection, supporting a role for these molecules in B-cell association with HCV. Stimulation of B cells with CD40 ligand and interleukin-4 promoted their ability to transinfect hepatoma cells. B cell-associated virus is resistant to trypsin proteolysis and HCV-specific neutralizing antibodies, consistent with particle internalization. HCV promoted the adhesion of primary B cells to Huh-7 hepatomas, providing a mechanism for B-cell retention in the infected liver. In summary, B cells may provide a vehicle for HCV to persist and transmit to the liver.

Selection of multiresistant hepatitis B virus during sequential nucleoside-analogue therapy

Hepatitis B virus (HBV) drug resistance to lamivudine is always accompanied by mutations in the viral polymerase gene at position 550, termed group 1 (M550V with L526M) or group 2 (M550I) mutations. The latter mutation has not been associated with famciclovir resistance. Thus, the addition of famciclovir to lamivudine therapy in persons with group 2 lamivudine resistance may lead to virus suppression. The effect of lamivudine/famciclovir combination therapy on HBV infection was monitored in 5 lamivudine-resistant patients by quantitative polymerase chain reaction and polymerase gene sequencing of serum virus. No patients treated with combination therapy had a decline in HBV load >1 log10. Continual evolution of the viral polymerase was detected in association with virologic resistance to both drugs. Cloning experiments identified the preexistence of these multidrug-resistant virus variants as minority species prior to addition of famciclovir therapy. HBV resistance to lamivudine monotherapy is associated with a complex mixture of variants that limit the efficacy of second-line nucleoside-analogue therapy. First-line potent combination therapy may reduce the emergence of HBV drug resistance.

Hepatitis C virus recurrence after liver transplantation

Cirrhosis due to hepatitis C virus (HCV) is now the most common indication of liver transplantation in Western Europe and the United States. In the absence of effective prophylaxis, recurrent HCV infection is almost inevitable. Though the natural history and intermediate term outcome of recurrent HCV are now better documented, those factors which may influence the recurrence of hepatitis and consequent progression of graft disease remain unclear. Interferon (IFN) as a sole agent for the treatment of recurrent infection has proved unsatisfactory. Early intervention with a combination of IFN and ribavirin seems promising, and this approach may prevent or delay progression of HCV related graft disease after liver transplantation.

Acute liver graft failure due to emergence of lamivudine resistant hepatitis B virus: rapid resolution during treatment with adefovir

BACKGROUND

Strategies for prevention of liver graft reinfection by hepatitis B virus (HBV) have been developed during recent years. Initially, passive immunoprophylaxis with high titre HBV immunoglobulin (HBIg), followed by lamivudine prophylaxis, and then the combination of lamivudine and HBIg have been employed. However, suboptimal use of the combination may be associated with failure of prophylaxis reflected by the emergence of HBV species with genetic changes that confer resistance to lamivudine and HBIg. Reinfection of the graft by HBV can be associated with rapid development of liver failure.

CASE REPORT

A 43 year old HBV infected man received lamivudine before transplantation, and lamivudine and HBIg after transplantation. Despite prophylaxis, graft reinfection and severe hepatitis were observed. The observed serological evolution and genetic sequencing of the emergent HBV species suggested selection of lamivudine resistant and surface antigen escape mutants consecutively. Adefovir treatment began after the development of graft failure.

OUTCOME

A rapid exponential decline in serum HBV titre was observed. Liver function tests normalised and signs of liver failure resolved.

CONCLUSION

The use of HBIg and lamivudine permits prevention of graft reinfection by HBV for the majority of patients. Adefovir, a potent inhibitor of lamivudine resistant HBV, should be used when failure of prophylaxis is associated with graft hepatitis.

Use of real-time PCR and fluorimetry to detect lamivudine resistance-associated mutations in hepatitis B virus

Very rapid amplification of DNA by PCR in small volumes can be continuously monitored by the detection of the binding of probes with a rapid cycler with built-in fluorometric detection. Primers were designed to amplify approximately 100 bp of the polymerase gene of hepatitis B virus (HBV) spanning codon 550, where mutations associated with resistance to lamivudine invariably occur. Four hybridization probes were synthesized: one was 3' labelled with fluorescein and hybridized upstream of codon 550. The others were 5' labelled with Cy5 and 3' labelled with biotin and spanned codon 550. The Cy5-labelled oligonucleotides contained either wild-type (ATG) or mutant (GTG or ATT) sequences. A Cy5-labelled probe and either the fluorescein-labelled probe or Sybr Green 1 (a compound that fluoresces when bound to double-stranded DNA) were included in each PCR. After completion of the amplification by using a LightCycler (Idaho Technology), the temperature at which the Cy5 probe melted from the product was determined in a melt program that took ca. 3 min. Pre- and posttreatment samples from eight patients (five chronic and three transplant) who failed lamivudine treatment were amplified, and the presence of mutations in codon 550 was determined by ABI sequencing and by using the LightCycler; in some cases PCR products were also cloned, and multiple clones were sequenced. Concordant results were obtained in all cases. We found the LightCycler to be better at resolving the sequences of genomic mixtures; for example, two samples showed a sequence at codon 550 of (A/G)T(G/T), which was found by fluorimetry to be mixtures of GTG and ATT but no ATG, and this finding was confirmed by the sequencing of clones. However, this approach was not more sensitive than population sequencing for the detection of the presence of mixtures. Overall, this pilot study has demonstrated an approach that could be an extremely rapid and economical method for the detection of lamivudine resistance-associated mutations in HBV.

Hepatitis C virus and nonliver solid organ transplantation

: Hepatitis C virus (HCV) infection is common in solid organ allograft recipients and is a significant cause of morbidity and mortality after transplantation, so effective management will improve outcomes. In this review, we discuss the extent of the problem associated with HCV infection in donors and kidney, heart, and lung transplant candidates and recipients and recommend follow-up and treatment.Patients with end-stage kidney disease without cirrhosis and selected patients with early-stage cirrhosis can be considered for kidney transplant alone. In HCV-infected kidney allograft recipients, the progression of fibrosis should be evaluated serially by Fibroscan or serologic measures of fibrosis. Transplantation of kidneys from HCV-positive donors should be restricted to HCV-positive recipients as it is associated with a reduced time waiting for a graft and does not affect posttransplant outcomes. Hepatitis C virus antiviral therapy should be considered for all HCV-RNA-positive kidney transplant candidates, irrespective of the baseline liver histopathology. Protease inhibitors have yet to be fully evaluated in patients with renal dysfunction and in the transplant population. As these agents may cause anemia in patients with normal renal function, tolerability may be a problem in patients with end-stage kidney disease.The impact of HCV infection on survival in heart and lung transplantation is unclear. Because of the shortage of organs, few HCV-infected patients are accepted for transplantation.Universal use of nucleic acid amplification testing (NAT) for the screening of potential organ donors should be reserved to high-risk donors. Assays that quantify HCV core antigen may become more cost-effective than NAT for the screening of potential organ donors.

Enhanced (cytomegalovirus) viral replication associated with septic bacterial complications in liver transplant recipients

BACKGROUND

Complications of the biliary anastomosis are the principal cause of clinically serious bacterial sepsis in liver transplant recipients. Reported series suggest an association of bacterial and fungal infection with cytomegalovirus (CMV) infection, although the mechanism of this association is unclear.

METHODS

We examined the association of serious bacterial sepsis with CMV replication in a cohort of 106 consecutive liver transplant recipients. Sequentially collected buffy coats were examined with a polymerase chain reaction (PCR) assay that has been shown to have good predictive value for the development of CMV infection. For selected patients, CMV-specific IgM response and serum tumor necrosis factor-alpha (TNF-alpha) were also measured.

RESULTS

Ten of 13 patients with serious bacterial sepsis developed buffy coat PCR positivity, compared with 26 of 93 patients without bacterial sepsis (chi-square, P<0.001). Ten of 10 septic recipients with a seropositive liver donor developed PCR positivity. For 9 of 10 recipients, bacterial sepsis developed before PCR positivity. Bacterial sepsis was associated with high serum levels of TNF-alpha. Immune response to CMV (reflected by the appearance CMV-specific IgM) was apparently affected by bacterial sepsis, and IgM response was not observed for the three septic patients who died during the study period.

CONCLUSIONS

We conclude that CMV replication is encouraged by serious bacterial sepsis. Replication may be promoted by high antecedent levels of TNF-alpha, and/or by poor immune response to CMV in the context of serious bacterial infection.

Chronic hepatitis C viral infection subverts vaccine-induced T-cell immunity in humans

Adenoviral vectors encoding hepatitis C virus (HCV) nonstructural (NS) proteins induce multispecific, high-magnitude, durable CD4(+) and CD8(+) T-cell responses in healthy volunteers. We assessed the capacity of these vaccines to induce functional HCV-specific immune responses and determine T-cell cross-reactivity to endogenous virus in patients with chronic HCV infection. HCV genotype 1-infected patients were vaccinated using heterologous adenoviral vectors (ChAd3-NSmut and Ad6-NSmut) encoding HCV NS proteins in a dose escalation, prime-boost regimen, with and without concomitant pegylated interferon-α/ribavirin therapy. Analysis of immune responses ex vivo used human leukocyte antigen class I pentamers, intracellular cytokine staining, and fine mapping in interferon-γ enzyme-linked immunospot assays. Cross-reactivity of T cells with population and endogenous viral variants was determined following viral sequence analysis. Compared to healthy volunteers, the magnitude of HCV-specific T-cell responses following vaccination was markedly reduced. CD8(+) HCV-specific T-cell responses were detected in 15/24 patients at the highest dose, whereas CD4(+) T-cell responses were rarely detectable. Analysis of the host circulating viral sequence showed that T-cell responses were rarely elicited when there was sequence homology between vaccine immunogen and endogenous virus. In contrast, T cells were induced in the context of genetic mismatch between vaccine immunogen and endogenous virus; however, these commonly failed to recognize circulating epitope variants and had a distinct partially functional phenotype. Vaccination was well tolerated but had no significant effect on HCV viral load.

CONCLUSION

Vaccination with potent HCV adenoviral vectored vaccines fails to restore T-cell immunity except where there is genetic mismatch between vaccine immunogen and endogenous virus; this highlights the major challenge of overcoming T-cell exhaustion in the context of persistent antigen exposure with implications for cancer and other persistent infections.

Recovery despite impaired cerebral perfusion in fulminant hepatic failure

We report 4 patients with fulminant hepatic failure who developed prolonged intracranial hypertension (> 35 mm Hg for 24-38 h) that was refractory to standard therapy and associated with impaired cerebral perfusion pressure (< 50 mm Hg for 2-72 h). All survived with complete neurological recovery. Refractory elevation of intracranial pressure and reduced cerebral perfusion pressure are generally thought to contra-indicate liver transplantation in hepatic failure and are indications to withdraw support. Our observations challenge this concept.